Replace Q_DECL_NOEXCEPT with noexcept in corelib

In preparation of Qt6 move away from pre-C++11 macros.

Change-Id: I44126693c20c18eca5620caab4f7e746218e0ce3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

153 files changed, 2269 insertions, 2269 deletions

diff --git a/src/corelib/codecs/qtextcodec.cpp b/src/corelib/codecs/qtextcodec.cpp
index e2598b7858..cac631d770 100644
--- a/src/corelib/codecs/qtextcodec.cpp
+++ b/src/corelib/codecs/qtextcodec.cpp
@@ -1061,7 +1061,7 @@ QString QTextDecoder::toUnicode(const char *chars, int len)
 }
 
 // in qstring.cpp:
-void qt_from_latin1(ushort *dst, const char *str, size_t size) Q_DECL_NOTHROW;
+void qt_from_latin1(ushort *dst, const char *str, size_t size) noexcept;
 
 /*! \overload
 
diff --git a/src/corelib/codecs/qutfcodec.cpp b/src/corelib/codecs/qutfcodec.cpp
index 643c8ee475..85736fdf02 100644
--- a/src/corelib/codecs/qutfcodec.cpp
+++ b/src/corelib/codecs/qutfcodec.cpp
@@ -54,7 +54,7 @@ static const uchar utf8bom[] = { 0xef, 0xbb, 0xbf };
 
 #if (defined(__SSE2__) && defined(QT_COMPILER_SUPPORTS_SSE2)) \
     || (defined(__ARM_NEON__) && defined(Q_PROCESSOR_ARM_64))
-static Q_ALWAYS_INLINE uint qBitScanReverse(unsigned v) Q_DECL_NOTHROW
+static Q_ALWAYS_INLINE uint qBitScanReverse(unsigned v) noexcept
 {
     uint result = qCountLeadingZeroBits(v);
     // Now Invert the result: clz will count *down* from the msb to the lsb, so the msb index is 31
@@ -504,7 +504,7 @@ QString QUtf8::convertToUnicode(const char *chars, int len)
     This function never throws.
 */
 
-QChar *QUtf8::convertToUnicode(QChar *buffer, const char *chars, int len) Q_DECL_NOTHROW
+QChar *QUtf8::convertToUnicode(QChar *buffer, const char *chars, int len) noexcept
 {
     ushort *dst = reinterpret_cast<ushort *>(buffer);
     const uchar *src = reinterpret_cast<const uchar *>(chars);
diff --git a/src/corelib/codecs/qutfcodec_p.h b/src/corelib/codecs/qutfcodec_p.h
index b24283ac5e..083e16317a 100644
--- a/src/corelib/codecs/qutfcodec_p.h
+++ b/src/corelib/codecs/qutfcodec_p.h
@@ -291,7 +291,7 @@ enum DataEndianness
 
 struct QUtf8
 {
-    static QChar *convertToUnicode(QChar *, const char *, int) Q_DECL_NOTHROW;
+    static QChar *convertToUnicode(QChar *, const char *, int) noexcept;
     static QString convertToUnicode(const char *, int);
     static QString convertToUnicode(const char *, int, QTextCodec::ConverterState *);
     static QByteArray convertFromUnicode(const QChar *, int);
diff --git a/src/corelib/global/qflags.h b/src/corelib/global/qflags.h
index 6aa6850c69..65f4892472 100644
--- a/src/corelib/global/qflags.h
+++ b/src/corelib/global/qflags.h
@@ -54,21 +54,21 @@ class QFlag
 {
     int i;
 public:
-    Q_DECL_CONSTEXPR inline QFlag(int value) Q_DECL_NOTHROW : i(value) {}
-    Q_DECL_CONSTEXPR inline operator int() const Q_DECL_NOTHROW { return i; }
+    Q_DECL_CONSTEXPR inline QFlag(int value) noexcept : i(value) {}
+    Q_DECL_CONSTEXPR inline operator int() const noexcept { return i; }
 
 #if !defined(Q_CC_MSVC)
     // Microsoft Visual Studio has buggy behavior when it comes to
     // unsigned enums: even if the enum is unsigned, the enum tags are
     // always signed
 #  if !defined(__LP64__) && !defined(Q_CLANG_QDOC)
-    Q_DECL_CONSTEXPR inline QFlag(long value) Q_DECL_NOTHROW : i(int(value)) {}
-    Q_DECL_CONSTEXPR inline QFlag(ulong value) Q_DECL_NOTHROW : i(int(long(value))) {}
+    Q_DECL_CONSTEXPR inline QFlag(long value) noexcept : i(int(value)) {}
+    Q_DECL_CONSTEXPR inline QFlag(ulong value) noexcept : i(int(long(value))) {}
 #  endif
-    Q_DECL_CONSTEXPR inline QFlag(uint value) Q_DECL_NOTHROW : i(int(value)) {}
-    Q_DECL_CONSTEXPR inline QFlag(short value) Q_DECL_NOTHROW : i(int(value)) {}
-    Q_DECL_CONSTEXPR inline QFlag(ushort value) Q_DECL_NOTHROW : i(int(uint(value))) {}
-    Q_DECL_CONSTEXPR inline operator uint() const Q_DECL_NOTHROW { return uint(i); }
+    Q_DECL_CONSTEXPR inline QFlag(uint value) noexcept : i(int(value)) {}
+    Q_DECL_CONSTEXPR inline QFlag(short value) noexcept : i(int(value)) {}
+    Q_DECL_CONSTEXPR inline QFlag(ushort value) noexcept : i(int(uint(value))) {}
+    Q_DECL_CONSTEXPR inline operator uint() const noexcept { return uint(i); }
 #endif
 };
 Q_DECLARE_TYPEINFO(QFlag, Q_PRIMITIVE_TYPE);
@@ -77,12 +77,12 @@ class QIncompatibleFlag
 {
     int i;
 public:
-    Q_DECL_CONSTEXPR inline explicit QIncompatibleFlag(int i) Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline operator int() const Q_DECL_NOTHROW { return i; }
+    Q_DECL_CONSTEXPR inline explicit QIncompatibleFlag(int i) noexcept;
+    Q_DECL_CONSTEXPR inline operator int() const noexcept { return i; }
 };
 Q_DECLARE_TYPEINFO(QIncompatibleFlag, Q_PRIMITIVE_TYPE);
 
-Q_DECL_CONSTEXPR inline QIncompatibleFlag::QIncompatibleFlag(int value) Q_DECL_NOTHROW : i(value) {}
+Q_DECL_CONSTEXPR inline QIncompatibleFlag::QIncompatibleFlag(int value) noexcept : i(value) {}
 
 
 #ifndef Q_NO_TYPESAFE_FLAGS
@@ -117,38 +117,38 @@ public:
     Q_DECL_CONSTEXPR inline QFlags(const QFlags &other);
     Q_DECL_CONSTEXPR inline QFlags &operator=(const QFlags &other);
 #endif
-    Q_DECL_CONSTEXPR inline QFlags(Enum flags) Q_DECL_NOTHROW : i(Int(flags)) {}
-    Q_DECL_CONSTEXPR inline QFlags(Zero = nullptr) Q_DECL_NOTHROW : i(0) {}
-    Q_DECL_CONSTEXPR inline QFlags(QFlag flag) Q_DECL_NOTHROW : i(flag) {}
+    Q_DECL_CONSTEXPR inline QFlags(Enum flags) noexcept : i(Int(flags)) {}
+    Q_DECL_CONSTEXPR inline QFlags(Zero = nullptr) noexcept : i(0) {}
+    Q_DECL_CONSTEXPR inline QFlags(QFlag flag) noexcept : i(flag) {}
 
 #ifdef Q_COMPILER_INITIALIZER_LISTS
-    Q_DECL_CONSTEXPR inline QFlags(std::initializer_list<Enum> flags) Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR inline QFlags(std::initializer_list<Enum> flags) noexcept
         : i(initializer_list_helper(flags.begin(), flags.end())) {}
 #endif
 
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(int mask) Q_DECL_NOTHROW { i &= mask; return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(uint mask) Q_DECL_NOTHROW { i &= mask; return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(Enum mask) Q_DECL_NOTHROW { i &= Int(mask); return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(QFlags other) Q_DECL_NOTHROW { i |= other.i; return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(Enum other) Q_DECL_NOTHROW { i |= Int(other); return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(QFlags other) Q_DECL_NOTHROW { i ^= other.i; return *this; }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(Enum other) Q_DECL_NOTHROW { i ^= Int(other); return *this; }
-
-    Q_DECL_CONSTEXPR inline operator Int() const Q_DECL_NOTHROW { return i; }
-
-    Q_DECL_CONSTEXPR inline QFlags operator|(QFlags other) const Q_DECL_NOTHROW { return QFlags(QFlag(i | other.i)); }
-    Q_DECL_CONSTEXPR inline QFlags operator|(Enum other) const Q_DECL_NOTHROW { return QFlags(QFlag(i | Int(other))); }
-    Q_DECL_CONSTEXPR inline QFlags operator^(QFlags other) const Q_DECL_NOTHROW { return QFlags(QFlag(i ^ other.i)); }
-    Q_DECL_CONSTEXPR inline QFlags operator^(Enum other) const Q_DECL_NOTHROW { return QFlags(QFlag(i ^ Int(other))); }
-    Q_DECL_CONSTEXPR inline QFlags operator&(int mask) const Q_DECL_NOTHROW { return QFlags(QFlag(i & mask)); }
-    Q_DECL_CONSTEXPR inline QFlags operator&(uint mask) const Q_DECL_NOTHROW { return QFlags(QFlag(i & mask)); }
-    Q_DECL_CONSTEXPR inline QFlags operator&(Enum other) const Q_DECL_NOTHROW { return QFlags(QFlag(i & Int(other))); }
-    Q_DECL_CONSTEXPR inline QFlags operator~() const Q_DECL_NOTHROW { return QFlags(QFlag(~i)); }
-
-    Q_DECL_CONSTEXPR inline bool operator!() const Q_DECL_NOTHROW { return !i; }
-
-    Q_DECL_CONSTEXPR inline bool testFlag(Enum flag) const Q_DECL_NOTHROW { return (i & Int(flag)) == Int(flag) && (Int(flag) != 0 || i == Int(flag) ); }
-    Q_DECL_RELAXED_CONSTEXPR inline QFlags &setFlag(Enum flag, bool on = true) Q_DECL_NOTHROW
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(int mask) noexcept { i &= mask; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(uint mask) noexcept { i &= mask; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator&=(Enum mask) noexcept { i &= Int(mask); return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(QFlags other) noexcept { i |= other.i; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator|=(Enum other) noexcept { i |= Int(other); return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(QFlags other) noexcept { i ^= other.i; return *this; }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &operator^=(Enum other) noexcept { i ^= Int(other); return *this; }
+
+    Q_DECL_CONSTEXPR inline operator Int() const noexcept { return i; }
+
+    Q_DECL_CONSTEXPR inline QFlags operator|(QFlags other) const noexcept { return QFlags(QFlag(i | other.i)); }
+    Q_DECL_CONSTEXPR inline QFlags operator|(Enum other) const noexcept { return QFlags(QFlag(i | Int(other))); }
+    Q_DECL_CONSTEXPR inline QFlags operator^(QFlags other) const noexcept { return QFlags(QFlag(i ^ other.i)); }
+    Q_DECL_CONSTEXPR inline QFlags operator^(Enum other) const noexcept { return QFlags(QFlag(i ^ Int(other))); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(int mask) const noexcept { return QFlags(QFlag(i & mask)); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(uint mask) const noexcept { return QFlags(QFlag(i & mask)); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(Enum other) const noexcept { return QFlags(QFlag(i & Int(other))); }
+    Q_DECL_CONSTEXPR inline QFlags operator~() const noexcept { return QFlags(QFlag(~i)); }
+
+    Q_DECL_CONSTEXPR inline bool operator!() const noexcept { return !i; }
+
+    Q_DECL_CONSTEXPR inline bool testFlag(Enum flag) const noexcept { return (i & Int(flag)) == Int(flag) && (Int(flag) != 0 || i == Int(flag) ); }
+    Q_DECL_RELAXED_CONSTEXPR inline QFlags &setFlag(Enum flag, bool on = true) noexcept
     {
         return on ? (*this |= flag) : (*this &= ~Int(flag));
     }
@@ -157,7 +157,7 @@ private:
 #ifdef Q_COMPILER_INITIALIZER_LISTS
     Q_DECL_CONSTEXPR static inline Int initializer_list_helper(typename std::initializer_list<Enum>::const_iterator it,
                                                                typename std::initializer_list<Enum>::const_iterator end)
-    Q_DECL_NOTHROW
+    noexcept
     {
         return (it == end ? Int(0) : (Int(*it) | initializer_list_helper(it + 1, end)));
     }
@@ -172,13 +172,13 @@ typedef QFlags<Enum> Flags;
 #endif
 
 #define Q_DECLARE_INCOMPATIBLE_FLAGS(Flags) \
-Q_DECL_CONSTEXPR inline QIncompatibleFlag operator|(Flags::enum_type f1, int f2) Q_DECL_NOTHROW \
+Q_DECL_CONSTEXPR inline QIncompatibleFlag operator|(Flags::enum_type f1, int f2) noexcept \
 { return QIncompatibleFlag(int(f1) | f2); }
 
 #define Q_DECLARE_OPERATORS_FOR_FLAGS(Flags) \
-Q_DECL_CONSTEXPR inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, Flags::enum_type f2) Q_DECL_NOTHROW \
+Q_DECL_CONSTEXPR inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, Flags::enum_type f2) noexcept \
 { return QFlags<Flags::enum_type>(f1) | f2; } \
-Q_DECL_CONSTEXPR inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, QFlags<Flags::enum_type> f2) Q_DECL_NOTHROW \
+Q_DECL_CONSTEXPR inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, QFlags<Flags::enum_type> f2) noexcept \
 { return f2 | f1; } Q_DECLARE_INCOMPATIBLE_FLAGS(Flags)
 
 
diff --git a/src/corelib/global/qfloat16.cpp b/src/corelib/global/qfloat16.cpp
index 110d7c4d7c..680268c59b 100644
--- a/src/corelib/global/qfloat16.cpp
+++ b/src/corelib/global/qfloat16.cpp
@@ -132,8 +132,8 @@ extern "C" {
 #  define f16cextern    extern
 #endif
 
-f16cextern void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) Q_DECL_NOTHROW;
-f16cextern void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) Q_DECL_NOTHROW;
+f16cextern void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) noexcept;
+f16cextern void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) noexcept;
 
 #undef f16cextern
 }
@@ -144,7 +144,7 @@ static inline bool hasFastF16()
     return true;
 }
 
-static void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) Q_DECL_NOTHROW
+static void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) noexcept
 {
     __fp16 *out_f16 = reinterpret_cast<__fp16 *>(out);
     qsizetype i = 0;
@@ -154,7 +154,7 @@ static void qFloatToFloat16_fast(quint16 *out, const float *in, qsizetype len) Q
         out_f16[i] = __fp16(in[i]);
 }
 
-static void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) Q_DECL_NOTHROW
+static void qFloatFromFloat16_fast(float *out, const quint16 *in, qsizetype len) noexcept
 {
     const __fp16 *in_f16 = reinterpret_cast<const __fp16 *>(in);
     qsizetype i = 0;
@@ -169,12 +169,12 @@ static inline bool hasFastF16()
     return false;
 }
 
-static void qFloatToFloat16_fast(quint16 *, const float *, qsizetype) Q_DECL_NOTHROW
+static void qFloatToFloat16_fast(quint16 *, const float *, qsizetype) noexcept
 {
     Q_UNREACHABLE();
 }
 
-static void qFloatFromFloat16_fast(float *, const quint16 *, qsizetype) Q_DECL_NOTHROW
+static void qFloatFromFloat16_fast(float *, const quint16 *, qsizetype) noexcept
 {
     Q_UNREACHABLE();
 }
@@ -186,7 +186,7 @@ static void qFloatFromFloat16_fast(float *, const quint16 *, qsizetype) Q_DECL_N
     Converts \a len floats from \a in to qfloat16 and stores them in \a out.
     Both \a in and \a out must have \a len allocated entries.
 */
-Q_CORE_EXPORT void qFloatToFloat16(qfloat16 *out, const float *in, qsizetype len) Q_DECL_NOTHROW
+Q_CORE_EXPORT void qFloatToFloat16(qfloat16 *out, const float *in, qsizetype len) noexcept
 {
     if (hasFastF16())
         return qFloatToFloat16_fast(reinterpret_cast<quint16 *>(out), in, len);
@@ -202,7 +202,7 @@ Q_CORE_EXPORT void qFloatToFloat16(qfloat16 *out, const float *in, qsizetype len
     Converts \a len qfloat16 from \a in to floats and stores them in \a out.
     Both \a in and \a out must have \a len allocated entries.
 */
-Q_CORE_EXPORT void qFloatFromFloat16(float *out, const qfloat16 *in, qsizetype len) Q_DECL_NOTHROW
+Q_CORE_EXPORT void qFloatFromFloat16(float *out, const qfloat16 *in, qsizetype len) noexcept
 {
     if (hasFastF16())
         return qFloatFromFloat16_fast(out, reinterpret_cast<const quint16 *>(in), len);
diff --git a/src/corelib/global/qfloat16.h b/src/corelib/global/qfloat16.h
index e823d0298b..243aea98be 100644
--- a/src/corelib/global/qfloat16.h
+++ b/src/corelib/global/qfloat16.h
@@ -67,14 +67,14 @@ QT_BEGIN_NAMESPACE
 class qfloat16
 {
 public:
-    constexpr inline qfloat16() Q_DECL_NOTHROW : b16(0) {}
-    inline qfloat16(float f) Q_DECL_NOTHROW;
-    inline operator float() const Q_DECL_NOTHROW;
+    constexpr inline qfloat16() noexcept : b16(0) {}
+    inline qfloat16(float f) noexcept;
+    inline operator float() const noexcept;
 
     // Support for qIs{Inf,NaN,Finite}:
-    bool isInf() const Q_DECL_NOTHROW { return ((b16 >> 8) & 0x7e) == 0x7c; }
-    bool isNaN() const Q_DECL_NOTHROW { return ((b16 >> 8) & 0x7e) == 0x7e; }
-    bool isFinite() const Q_DECL_NOTHROW { return ((b16 >> 8) & 0x7c) != 0x7c; }
+    bool isInf() const noexcept { return ((b16 >> 8) & 0x7e) == 0x7c; }
+    bool isNaN() const noexcept { return ((b16 >> 8) & 0x7e) == 0x7e; }
+    bool isFinite() const noexcept { return ((b16 >> 8) & 0x7c) != 0x7c; }
 private:
     quint16 b16;
 
@@ -84,29 +84,29 @@ private:
     Q_CORE_EXPORT static const quint32 basetable[];
     Q_CORE_EXPORT static const quint32 shifttable[];
 
-    friend bool qIsNull(qfloat16 f) Q_DECL_NOTHROW;
-    friend qfloat16 operator-(qfloat16 a) Q_DECL_NOTHROW;
+    friend bool qIsNull(qfloat16 f) noexcept;
+    friend qfloat16 operator-(qfloat16 a) noexcept;
 };
 
 Q_DECLARE_TYPEINFO(qfloat16, Q_PRIMITIVE_TYPE);
 
-Q_CORE_EXPORT void qFloatToFloat16(qfloat16 *, const float *, qsizetype length) Q_DECL_NOTHROW;
-Q_CORE_EXPORT void qFloatFromFloat16(float *, const qfloat16 *, qsizetype length) Q_DECL_NOTHROW;
+Q_CORE_EXPORT void qFloatToFloat16(qfloat16 *, const float *, qsizetype length) noexcept;
+Q_CORE_EXPORT void qFloatFromFloat16(float *, const qfloat16 *, qsizetype length) noexcept;
 
 // Complement qnumeric.h:
-Q_REQUIRED_RESULT inline bool qIsInf(qfloat16 f) Q_DECL_NOTHROW { return f.isInf(); }
-Q_REQUIRED_RESULT inline bool qIsNaN(qfloat16 f) Q_DECL_NOTHROW { return f.isNaN(); }
-Q_REQUIRED_RESULT inline bool qIsFinite(qfloat16 f) Q_DECL_NOTHROW { return f.isFinite(); }
+Q_REQUIRED_RESULT inline bool qIsInf(qfloat16 f) noexcept { return f.isInf(); }
+Q_REQUIRED_RESULT inline bool qIsNaN(qfloat16 f) noexcept { return f.isNaN(); }
+Q_REQUIRED_RESULT inline bool qIsFinite(qfloat16 f) noexcept { return f.isFinite(); }
 // Q_REQUIRED_RESULT quint32 qFloatDistance(qfloat16 a, qfloat16 b);
 
 // The remainder of these utility functions complement qglobal.h
-Q_REQUIRED_RESULT inline int qRound(qfloat16 d) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline int qRound(qfloat16 d) noexcept
 { return qRound(static_cast<float>(d)); }
 
-Q_REQUIRED_RESULT inline qint64 qRound64(qfloat16 d) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline qint64 qRound64(qfloat16 d) noexcept
 { return qRound64(static_cast<float>(d)); }
 
-Q_REQUIRED_RESULT inline bool qFuzzyCompare(qfloat16 p1, qfloat16 p2) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool qFuzzyCompare(qfloat16 p1, qfloat16 p2) noexcept
 {
     float f1 = static_cast<float>(p1);
     float f2 = static_cast<float>(p2);
@@ -119,19 +119,19 @@ Q_REQUIRED_RESULT inline bool qFuzzyCompare(qfloat16 p1, qfloat16 p2) Q_DECL_NOT
     return (qAbs(f1 - f2) * 102.5f <= qMin(qAbs(f1), qAbs(f2)));
 }
 
-Q_REQUIRED_RESULT inline bool qIsNull(qfloat16 f) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool qIsNull(qfloat16 f) noexcept
 {
     return (f.b16 & static_cast<quint16>(0x7fff)) == 0;
 }
 
-inline int qIntCast(qfloat16 f) Q_DECL_NOTHROW
+inline int qIntCast(qfloat16 f) noexcept
 { return int(static_cast<float>(f)); }
 
 #ifndef Q_QDOC
 QT_WARNING_PUSH
 QT_WARNING_DISABLE_CLANG("-Wc99-extensions")
 QT_WARNING_DISABLE_GCC("-Wold-style-cast")
-inline qfloat16::qfloat16(float f) Q_DECL_NOTHROW
+inline qfloat16::qfloat16(float f) noexcept
 {
 #if defined(QT_COMPILER_SUPPORTS_F16C) && defined(__F16C__)
     __m128 packsingle = _mm_set_ss(f);
@@ -149,7 +149,7 @@ inline qfloat16::qfloat16(float f) Q_DECL_NOTHROW
 }
 QT_WARNING_POP
 
-inline qfloat16::operator float() const Q_DECL_NOTHROW
+inline qfloat16::operator float() const noexcept
 {
 #if defined(QT_COMPILER_SUPPORTS_F16C) && defined(__F16C__)
     __m128i packhalf = _mm_cvtsi32_si128(b16);
@@ -169,23 +169,23 @@ inline qfloat16::operator float() const Q_DECL_NOTHROW
 }
 #endif
 
-inline qfloat16 operator-(qfloat16 a) Q_DECL_NOTHROW
+inline qfloat16 operator-(qfloat16 a) noexcept
 {
     qfloat16 f;
     f.b16 = a.b16 ^ quint16(0x8000);
     return f;
 }
 
-inline qfloat16 operator+(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return qfloat16(static_cast<float>(a) + static_cast<float>(b)); }
-inline qfloat16 operator-(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return qfloat16(static_cast<float>(a) - static_cast<float>(b)); }
-inline qfloat16 operator*(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return qfloat16(static_cast<float>(a) * static_cast<float>(b)); }
-inline qfloat16 operator/(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return qfloat16(static_cast<float>(a) / static_cast<float>(b)); }
+inline qfloat16 operator+(qfloat16 a, qfloat16 b) noexcept { return qfloat16(static_cast<float>(a) + static_cast<float>(b)); }
+inline qfloat16 operator-(qfloat16 a, qfloat16 b) noexcept { return qfloat16(static_cast<float>(a) - static_cast<float>(b)); }
+inline qfloat16 operator*(qfloat16 a, qfloat16 b) noexcept { return qfloat16(static_cast<float>(a) * static_cast<float>(b)); }
+inline qfloat16 operator/(qfloat16 a, qfloat16 b) noexcept { return qfloat16(static_cast<float>(a) / static_cast<float>(b)); }
 
 #define QF16_MAKE_ARITH_OP_FP(FP, OP) \
-    inline FP operator OP(qfloat16 lhs, FP rhs) Q_DECL_NOTHROW { return static_cast<FP>(lhs) OP rhs; } \
-    inline FP operator OP(FP lhs, qfloat16 rhs) Q_DECL_NOTHROW { return lhs OP static_cast<FP>(rhs); }
+    inline FP operator OP(qfloat16 lhs, FP rhs) noexcept { return static_cast<FP>(lhs) OP rhs; } \
+    inline FP operator OP(FP lhs, qfloat16 rhs) noexcept { return lhs OP static_cast<FP>(rhs); }
 #define QF16_MAKE_ARITH_OP_EQ_FP(FP, OP_EQ, OP) \
-    inline qfloat16& operator OP_EQ(qfloat16& lhs, FP rhs) Q_DECL_NOTHROW \
+    inline qfloat16& operator OP_EQ(qfloat16& lhs, FP rhs) noexcept \
     { lhs = qfloat16(float(static_cast<FP>(lhs) OP rhs)); return lhs; }
 #define QF16_MAKE_ARITH_OP(FP) \
     QF16_MAKE_ARITH_OP_FP(FP, +) \
@@ -203,8 +203,8 @@ QF16_MAKE_ARITH_OP(float)
 #undef QF16_MAKE_ARITH_OP_FP
 
 #define QF16_MAKE_ARITH_OP_INT(OP) \
-    inline double operator OP(qfloat16 lhs, int rhs) Q_DECL_NOTHROW { return static_cast<double>(lhs) OP rhs; } \
-    inline double operator OP(int lhs, qfloat16 rhs) Q_DECL_NOTHROW { return lhs OP static_cast<double>(rhs); }
+    inline double operator OP(qfloat16 lhs, int rhs) noexcept { return static_cast<double>(lhs) OP rhs; } \
+    inline double operator OP(int lhs, qfloat16 rhs) noexcept { return lhs OP static_cast<double>(rhs); }
 QF16_MAKE_ARITH_OP_INT(+)
 QF16_MAKE_ARITH_OP_INT(-)
 QF16_MAKE_ARITH_OP_INT(*)
@@ -215,16 +215,16 @@ QT_WARNING_PUSH
 QT_WARNING_DISABLE_CLANG("-Wfloat-equal")
 QT_WARNING_DISABLE_GCC("-Wfloat-equal")
 
-inline bool operator>(qfloat16 a, qfloat16 b)  Q_DECL_NOTHROW { return static_cast<float>(a) >  static_cast<float>(b); }
-inline bool operator<(qfloat16 a, qfloat16 b)  Q_DECL_NOTHROW { return static_cast<float>(a) <  static_cast<float>(b); }
-inline bool operator>=(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return static_cast<float>(a) >= static_cast<float>(b); }
-inline bool operator<=(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return static_cast<float>(a) <= static_cast<float>(b); }
-inline bool operator==(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return static_cast<float>(a) == static_cast<float>(b); }
-inline bool operator!=(qfloat16 a, qfloat16 b) Q_DECL_NOTHROW { return static_cast<float>(a) != static_cast<float>(b); }
+inline bool operator>(qfloat16 a, qfloat16 b)  noexcept { return static_cast<float>(a) >  static_cast<float>(b); }
+inline bool operator<(qfloat16 a, qfloat16 b)  noexcept { return static_cast<float>(a) <  static_cast<float>(b); }
+inline bool operator>=(qfloat16 a, qfloat16 b) noexcept { return static_cast<float>(a) >= static_cast<float>(b); }
+inline bool operator<=(qfloat16 a, qfloat16 b) noexcept { return static_cast<float>(a) <= static_cast<float>(b); }
+inline bool operator==(qfloat16 a, qfloat16 b) noexcept { return static_cast<float>(a) == static_cast<float>(b); }
+inline bool operator!=(qfloat16 a, qfloat16 b) noexcept { return static_cast<float>(a) != static_cast<float>(b); }
 
 #define QF16_MAKE_BOOL_OP_FP(FP, OP) \
-    inline bool operator OP(qfloat16 lhs, FP rhs) Q_DECL_NOTHROW { return static_cast<FP>(lhs) OP rhs; } \
-    inline bool operator OP(FP lhs, qfloat16 rhs) Q_DECL_NOTHROW { return lhs OP static_cast<FP>(rhs); }
+    inline bool operator OP(qfloat16 lhs, FP rhs) noexcept { return static_cast<FP>(lhs) OP rhs; } \
+    inline bool operator OP(FP lhs, qfloat16 rhs) noexcept { return lhs OP static_cast<FP>(rhs); }
 #define QF16_MAKE_BOOL_OP(FP) \
     QF16_MAKE_BOOL_OP_FP(FP, <) \
     QF16_MAKE_BOOL_OP_FP(FP, >) \
@@ -239,8 +239,8 @@ QF16_MAKE_BOOL_OP(float)
 #undef QF16_MAKE_BOOL_OP_FP
 
 #define QF16_MAKE_BOOL_OP_INT(OP) \
-    inline bool operator OP(qfloat16 a, int b) Q_DECL_NOTHROW { return static_cast<float>(a) OP b; } \
-    inline bool operator OP(int a, qfloat16 b) Q_DECL_NOTHROW { return a OP static_cast<float>(b); }
+    inline bool operator OP(qfloat16 a, int b) noexcept { return static_cast<float>(a) OP b; } \
+    inline bool operator OP(int a, qfloat16 b) noexcept { return a OP static_cast<float>(b); }
 QF16_MAKE_BOOL_OP_INT(>)
 QF16_MAKE_BOOL_OP_INT(<)
 QF16_MAKE_BOOL_OP_INT(>=)
@@ -254,7 +254,7 @@ QT_WARNING_POP
 /*!
   \internal
 */
-Q_REQUIRED_RESULT inline bool qFuzzyIsNull(qfloat16 f) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool qFuzzyIsNull(qfloat16 f) noexcept
 {
     return qAbs(static_cast<float>(f)) <= 0.001f;
 }
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index 7879109930..d95064af27 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -1147,12 +1147,12 @@ Q_STATIC_ASSERT((std::is_same<qsizetype, qptrdiff>::value));
     \sa QT_VERSION_STR, QLibraryInfo::version()
 */
 
-const char *qVersion() Q_DECL_NOTHROW
+const char *qVersion() noexcept
 {
     return QT_VERSION_STR;
 }
 
-bool qSharedBuild() Q_DECL_NOTHROW
+bool qSharedBuild() noexcept
 {
 #ifdef QT_SHARED
     return true;
@@ -3206,7 +3206,7 @@ QByteArray QSysInfo::bootUniqueId()
     The Q_CHECK_PTR macro calls this function if an allocation check
     fails.
 */
-void qt_check_pointer(const char *n, int l) Q_DECL_NOTHROW
+void qt_check_pointer(const char *n, int l) noexcept
 {
     // make separate printing calls so that the first one may flush;
     // the second one could want to allocate memory (fputs prints a
@@ -3233,7 +3233,7 @@ void qBadAlloc()
    Allows you to call std::terminate() without including <exception>.
    Called internally from QT_TERMINATE_ON_EXCEPTION
 */
-Q_NORETURN void qTerminate() Q_DECL_NOTHROW
+Q_NORETURN void qTerminate() noexcept
 {
     std::terminate();
 }
@@ -3242,7 +3242,7 @@ Q_NORETURN void qTerminate() Q_DECL_NOTHROW
 /*
   The Q_ASSERT macro calls this function when the test fails.
 */
-void qt_assert(const char *assertion, const char *file, int line) Q_DECL_NOTHROW
+void qt_assert(const char *assertion, const char *file, int line) noexcept
 {
     QMessageLogger(file, line, nullptr).fatal("ASSERT: \"%s\" in file %s, line %d", assertion, file, line);
 }
@@ -3250,7 +3250,7 @@ void qt_assert(const char *assertion, const char *file, int line) Q_DECL_NOTHROW
 /*
   The Q_ASSERT_X macro calls this function when the test fails.
 */
-void qt_assert_x(const char *where, const char *what, const char *file, int line) Q_DECL_NOTHROW
+void qt_assert_x(const char *where, const char *what, const char *file, int line) noexcept
 {
     QMessageLogger(file, line, nullptr).fatal("ASSERT failure in %s: \"%s\", file %s, line %d", where, what, file, line);
 }
@@ -3457,7 +3457,7 @@ QString qEnvironmentVariable(const char *varName)
 
     \sa qgetenv(), qEnvironmentVariable(), qEnvironmentVariableIsSet()
 */
-bool qEnvironmentVariableIsEmpty(const char *varName) Q_DECL_NOEXCEPT
+bool qEnvironmentVariableIsEmpty(const char *varName) noexcept
 {
     QMutexLocker locker(&environmentMutex);
 #ifdef Q_CC_MSVC
@@ -3492,7 +3492,7 @@ bool qEnvironmentVariableIsEmpty(const char *varName) Q_DECL_NOEXCEPT
 
     \sa qgetenv(), qEnvironmentVariable(), qEnvironmentVariableIsSet()
 */
-int qEnvironmentVariableIntValue(const char *varName, bool *ok) Q_DECL_NOEXCEPT
+int qEnvironmentVariableIntValue(const char *varName, bool *ok) noexcept
 {
     static const int NumBinaryDigitsPerOctalDigit = 3;
     static const int MaxDigitsForOctalInt =
@@ -3561,7 +3561,7 @@ int qEnvironmentVariableIntValue(const char *varName, bool *ok) Q_DECL_NOEXCEPT
 
     \sa qgetenv(), qEnvironmentVariable(), qEnvironmentVariableIsEmpty()
 */
-bool qEnvironmentVariableIsSet(const char *varName) Q_DECL_NOEXCEPT
+bool qEnvironmentVariableIsSet(const char *varName) noexcept
 {
     QMutexLocker locker(&environmentMutex);
 #ifdef Q_CC_MSVC
diff --git a/src/corelib/global/qglobal.h b/src/corelib/global/qglobal.h
index 223ebbcabe..f62d078035 100644
--- a/src/corelib/global/qglobal.h
+++ b/src/corelib/global/qglobal.h
@@ -411,7 +411,7 @@ typedef double qreal;
 #if !defined(QT_NAMESPACE) && defined(__cplusplus) && !defined(Q_QDOC)
 extern "C"
 #endif
-Q_CORE_EXPORT Q_DECL_CONST_FUNCTION const char *qVersion(void) Q_DECL_NOTHROW;
+Q_CORE_EXPORT Q_DECL_CONST_FUNCTION const char *qVersion(void) Q_DECL_NOEXCEPT;
 
 #if defined(__cplusplus)
 
@@ -730,7 +730,7 @@ inline void qt_noop(void) {}
 #  define QT_CATCH(A) catch (A)
 #  define QT_THROW(A) throw A
 #  define QT_RETHROW throw
-Q_NORETURN Q_DECL_COLD_FUNCTION Q_CORE_EXPORT void qTerminate() Q_DECL_NOTHROW;
+Q_NORETURN Q_DECL_COLD_FUNCTION Q_CORE_EXPORT void qTerminate() noexcept;
 #  ifdef Q_COMPILER_NOEXCEPT
 #    define QT_TERMINATE_ON_EXCEPTION(expr) do { expr; } while (false)
 #  else
@@ -738,7 +738,7 @@ Q_NORETURN Q_DECL_COLD_FUNCTION Q_CORE_EXPORT void qTerminate() Q_DECL_NOTHROW;
 #  endif
 #endif
 
-Q_CORE_EXPORT Q_DECL_CONST_FUNCTION bool qSharedBuild() Q_DECL_NOTHROW;
+Q_CORE_EXPORT Q_DECL_CONST_FUNCTION bool qSharedBuild() noexcept;
 
 #ifndef Q_OUTOFLINE_TEMPLATE
 #  define Q_OUTOFLINE_TEMPLATE
@@ -781,7 +781,7 @@ Q_CORE_EXPORT QString qt_error_string(int errorCode = -1);
 Q_NORETURN
 #endif
 Q_DECL_COLD_FUNCTION
-Q_CORE_EXPORT void qt_assert(const char *assertion, const char *file, int line) Q_DECL_NOTHROW;
+Q_CORE_EXPORT void qt_assert(const char *assertion, const char *file, int line) noexcept;
 
 #if !defined(Q_ASSERT)
 #  if defined(QT_NO_DEBUG) && !defined(QT_FORCE_ASSERTS)
@@ -799,7 +799,7 @@ Q_CORE_EXPORT void qt_assert(const char *assertion, const char *file, int line)
 Q_NORETURN
 #endif
 Q_DECL_COLD_FUNCTION
-Q_CORE_EXPORT void qt_assert_x(const char *where, const char *what, const char *file, int line) Q_DECL_NOTHROW;
+Q_CORE_EXPORT void qt_assert_x(const char *where, const char *what, const char *file, int line) noexcept;
 
 #if !defined(Q_ASSERT_X)
 #  if defined(QT_NO_DEBUG) && !defined(QT_FORCE_ASSERTS)
@@ -809,7 +809,7 @@ Q_CORE_EXPORT void qt_assert_x(const char *where, const char *what, const char *
 #  endif
 #endif
 
-Q_NORETURN Q_CORE_EXPORT void qt_check_pointer(const char *, int) Q_DECL_NOTHROW;
+Q_NORETURN Q_CORE_EXPORT void qt_check_pointer(const char *, int) noexcept;
 Q_DECL_COLD_FUNCTION
 Q_CORE_EXPORT void qBadAlloc();
 
@@ -968,7 +968,7 @@ QT_WARNING_DISABLE_MSVC(4530) /* C++ exception handler used, but unwind semantic
 
 // this adds const to non-const objects (like std::as_const)
 template <typename T>
-Q_DECL_CONSTEXPR typename std::add_const<T>::type &qAsConst(T &t) Q_DECL_NOTHROW { return t; }
+Q_DECL_CONSTEXPR typename std::add_const<T>::type &qAsConst(T &t) noexcept { return t; }
 // prevent rvalue arguments:
 template <typename T>
 void qAsConst(const T &&) Q_DECL_EQ_DELETE;
@@ -1130,11 +1130,11 @@ template <typename... Args>
 struct QNonConstOverload
 {
     template <typename R, typename T>
-    Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...)) const Q_DECL_NOTHROW -> decltype(ptr)
+    Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...)) const noexcept -> decltype(ptr)
     { return ptr; }
 
     template <typename R, typename T>
-    static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...)) Q_DECL_NOTHROW -> decltype(ptr)
+    static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...)) noexcept -> decltype(ptr)
     { return ptr; }
 };
 
@@ -1142,11 +1142,11 @@ template <typename... Args>
 struct QConstOverload
 {
     template <typename R, typename T>
-    Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...) const) const Q_DECL_NOTHROW -> decltype(ptr)
+    Q_DECL_CONSTEXPR auto operator()(R (T::*ptr)(Args...) const) const noexcept -> decltype(ptr)
     { return ptr; }
 
     template <typename R, typename T>
-    static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...) const) Q_DECL_NOTHROW -> decltype(ptr)
+    static Q_DECL_CONSTEXPR auto of(R (T::*ptr)(Args...) const) noexcept -> decltype(ptr)
     { return ptr; }
 };
 
@@ -1159,11 +1159,11 @@ struct QOverload : QConstOverload<Args...>, QNonConstOverload<Args...>
     using QNonConstOverload<Args...>::operator();
 
     template <typename R>
-    Q_DECL_CONSTEXPR auto operator()(R (*ptr)(Args...)) const Q_DECL_NOTHROW -> decltype(ptr)
+    Q_DECL_CONSTEXPR auto operator()(R (*ptr)(Args...)) const noexcept -> decltype(ptr)
     { return ptr; }
 
     template <typename R>
-    static Q_DECL_CONSTEXPR auto of(R (*ptr)(Args...)) Q_DECL_NOTHROW -> decltype(ptr)
+    static Q_DECL_CONSTEXPR auto of(R (*ptr)(Args...)) noexcept -> decltype(ptr)
     { return ptr; }
 };
 
@@ -1184,9 +1184,9 @@ Q_CORE_EXPORT QString qEnvironmentVariable(const char *varName, const QString &d
 Q_CORE_EXPORT bool qputenv(const char *varName, const QByteArray& value);
 Q_CORE_EXPORT bool qunsetenv(const char *varName);
 
-Q_CORE_EXPORT bool qEnvironmentVariableIsEmpty(const char *varName) Q_DECL_NOEXCEPT;
-Q_CORE_EXPORT bool qEnvironmentVariableIsSet(const char *varName) Q_DECL_NOEXCEPT;
-Q_CORE_EXPORT int  qEnvironmentVariableIntValue(const char *varName, bool *ok=nullptr) Q_DECL_NOEXCEPT;
+Q_CORE_EXPORT bool qEnvironmentVariableIsEmpty(const char *varName) noexcept;
+Q_CORE_EXPORT bool qEnvironmentVariableIsSet(const char *varName) noexcept;
+Q_CORE_EXPORT int  qEnvironmentVariableIntValue(const char *varName, bool *ok=nullptr) noexcept;
 
 inline int qIntCast(double f) { return int(f); }
 inline int qIntCast(float f) { return int(f); }
diff --git a/src/corelib/global/qglobalstatic.h b/src/corelib/global/qglobalstatic.h
index 93d71cee57..6d27e3a984 100644
--- a/src/corelib/global/qglobalstatic.h
+++ b/src/corelib/global/qglobalstatic.h
@@ -79,7 +79,7 @@ enum GuardValues {
     Q_GLOBAL_STATIC_INTERNAL_DECORATION Type *innerFunction()   \
     {                                                           \
         struct HolderBase {                                     \
-            ~HolderBase() Q_DECL_NOTHROW                        \
+            ~HolderBase() noexcept                        \
             { if (guard.load() == QtGlobalStatic::Initialized)  \
                   guard.store(QtGlobalStatic::Destroyed); }     \
         };                                                      \
diff --git a/src/corelib/global/qlibraryinfo.cpp b/src/corelib/global/qlibraryinfo.cpp
index 88cc5b0b01..c3eb469767 100644
--- a/src/corelib/global/qlibraryinfo.cpp
+++ b/src/corelib/global/qlibraryinfo.cpp
@@ -350,7 +350,7 @@ QLibraryInfo::buildDate()
   \since 5.3
 */
 
-const char *QLibraryInfo::build() Q_DECL_NOTHROW
+const char *QLibraryInfo::build() noexcept
 {
     return QT_BUILD_STR;
 }
@@ -377,7 +377,7 @@ QLibraryInfo::isDebugBuild()
 
     \sa qVersion()
 */
-QVersionNumber QLibraryInfo::version() Q_DECL_NOTHROW
+QVersionNumber QLibraryInfo::version() noexcept
 {
     return QVersionNumber(QT_VERSION_MAJOR, QT_VERSION_MINOR, QT_VERSION_PATCH);
 }
diff --git a/src/corelib/global/qlibraryinfo.h b/src/corelib/global/qlibraryinfo.h
index 80fc5bd4fc..20fd3897f7 100644
--- a/src/corelib/global/qlibraryinfo.h
+++ b/src/corelib/global/qlibraryinfo.h
@@ -62,12 +62,12 @@ public:
 #endif // QT_DEPRECATED_SINCE(5, 5)
 #endif // datestring
 
-    static const char * build() Q_DECL_NOTHROW;
+    static const char * build() noexcept;
 
     static bool isDebugBuild();
 
 #ifndef QT_BOOTSTRAPPED
-    static QVersionNumber version() Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static QVersionNumber version() noexcept Q_DECL_CONST_FUNCTION;
 #endif
 
     enum LibraryLocation
diff --git a/src/corelib/global/qlogging.cpp b/src/corelib/global/qlogging.cpp
index b2093101fa..a4d86e393b 100644
--- a/src/corelib/global/qlogging.cpp
+++ b/src/corelib/global/qlogging.cpp
@@ -346,7 +346,7 @@ using namespace QtPrivate;
 */
 
 #if defined(Q_CC_MSVC) && defined(QT_DEBUG) && defined(_DEBUG) && defined(_CRT_ERROR)
-static inline void convert_to_wchar_t_elided(wchar_t *d, size_t space, const char *s) Q_DECL_NOEXCEPT
+static inline void convert_to_wchar_t_elided(wchar_t *d, size_t space, const char *s) noexcept
 {
     size_t len = qstrlen(s);
     if (len + 1 > space) {
@@ -529,7 +529,7 @@ QDebug QMessageLogger::debug(QMessageLogger::CategoryFunction catFunc) const
 
     \sa QNoDebug, qDebug()
 */
-QNoDebug QMessageLogger::noDebug() const Q_DECL_NOTHROW
+QNoDebug QMessageLogger::noDebug() const noexcept
 {
     return QNoDebug();
 }
@@ -875,7 +875,7 @@ QDebug QMessageLogger::critical(QMessageLogger::CategoryFunction catFunc) const
 
     \sa qFatal()
 */
-void QMessageLogger::fatal(const char *msg, ...) const Q_DECL_NOTHROW
+void QMessageLogger::fatal(const char *msg, ...) const noexcept
 {
     QString message;
 
diff --git a/src/corelib/global/qlogging.h b/src/corelib/global/qlogging.h
index dded09999b..8f39780112 100644
--- a/src/corelib/global/qlogging.h
+++ b/src/corelib/global/qlogging.h
@@ -121,7 +121,7 @@ public:
     Q_NORETURN
 #endif
     Q_DECL_COLD_FUNCTION
-    void fatal(const char *msg, ...) const Q_DECL_NOTHROW Q_ATTRIBUTE_FORMAT_PRINTF(2, 3);
+    void fatal(const char *msg, ...) const noexcept Q_ATTRIBUTE_FORMAT_PRINTF(2, 3);
 
 #ifndef QT_NO_DEBUG_STREAM
     QDebug debug() const;
@@ -137,7 +137,7 @@ public:
     QDebug critical(const QLoggingCategory &cat) const;
     QDebug critical(CategoryFunction catFunc) const;
 
-    QNoDebug noDebug() const Q_DECL_NOTHROW;
+    QNoDebug noDebug() const noexcept;
 #endif // QT_NO_DEBUG_STREAM
 
 private:
diff --git a/src/corelib/global/qnamespace.h b/src/corelib/global/qnamespace.h
index 6488426e64..610d7e4db7 100644
--- a/src/corelib/global/qnamespace.h
+++ b/src/corelib/global/qnamespace.h
@@ -50,10 +50,10 @@ QT_BEGIN_NAMESPACE
 
 #if !defined(Q_QDOC) && !defined(Q_MOC_RUN)
 struct QMetaObject;
-const QMetaObject *qt_getQtMetaObject() Q_DECL_NOEXCEPT; // defined in qobject.h (which can't be included here)
+const QMetaObject *qt_getQtMetaObject() noexcept; // defined in qobject.h (which can't be included here)
 #define QT_Q_ENUM(ENUM) \
-    inline const QMetaObject *qt_getEnumMetaObject(ENUM) Q_DECL_NOEXCEPT { return qt_getQtMetaObject(); } \
-    inline Q_DECL_CONSTEXPR const char *qt_getEnumName(ENUM) Q_DECL_NOEXCEPT { return #ENUM; }
+    inline const QMetaObject *qt_getEnumMetaObject(ENUM) noexcept { return qt_getQtMetaObject(); } \
+    inline Q_DECL_CONSTEXPR const char *qt_getEnumName(ENUM) noexcept { return #ENUM; }
 #define QT_Q_FLAG(ENUM) QT_Q_ENUM(ENUM)
 #else
 #define QT_Q_ENUM Q_ENUM
diff --git a/src/corelib/global/qnumeric_p.h b/src/corelib/global/qnumeric_p.h
index 56e670c477..21f9cfbef0 100644
--- a/src/corelib/global/qnumeric_p.h
+++ b/src/corelib/global/qnumeric_p.h
@@ -126,7 +126,7 @@ Q_DECL_CONST_FUNCTION static inline int fpclassify(float f) { return std::fpclas
 #endif
 }
 
-Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_inf() Q_DECL_NOEXCEPT
+Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_inf() noexcept
 {
     Q_STATIC_ASSERT_X(std::numeric_limits<double>::has_infinity,
                       "platform has no definition for infinity for type double");
@@ -134,7 +134,7 @@ Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_inf() Q_DECL_NOEX
 }
 
 // Signaling NaN
-Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_snan() Q_DECL_NOEXCEPT
+Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_snan() noexcept
 {
     Q_STATIC_ASSERT_X(std::numeric_limits<double>::has_signaling_NaN,
                       "platform has no definition for signaling NaN for type double");
@@ -142,7 +142,7 @@ Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_snan() Q_DECL_NOE
 }
 
 // Quiet NaN
-Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_qnan() Q_DECL_NOEXCEPT
+Q_DECL_CONSTEXPR Q_DECL_CONST_FUNCTION static inline double qt_qnan() noexcept
 {
     Q_STATIC_ASSERT_X(std::numeric_limits<double>::has_quiet_NaN,
                       "platform has no definition for quiet NaN for type double");
diff --git a/src/corelib/global/qrandom.cpp b/src/corelib/global/qrandom.cpp
index 90df8653a7..fbc4222763 100644
--- a/src/corelib/global/qrandom.cpp
+++ b/src/corelib/global/qrandom.cpp
@@ -91,7 +91,7 @@ DECLSPEC_IMPORT BOOLEAN WINAPI SystemFunction036(PVOID RandomBuffer, ULONG Rando
 QT_BEGIN_NAMESPACE
 
 #if defined(Q_PROCESSOR_X86) && QT_COMPILER_SUPPORTS_HERE(RDRND)
-static qsizetype qt_random_cpu(void *buffer, qsizetype count) Q_DECL_NOTHROW;
+static qsizetype qt_random_cpu(void *buffer, qsizetype count) noexcept;
 
 #  ifdef Q_PROCESSOR_X86_64
 #    define _rdrandXX_step _rdrand64_step
@@ -99,7 +99,7 @@ static qsizetype qt_random_cpu(void *buffer, qsizetype count) Q_DECL_NOTHROW;
 #    define _rdrandXX_step _rdrand32_step
 #  endif
 
-static QT_FUNCTION_TARGET(RDRND) qsizetype qt_random_cpu(void *buffer, qsizetype count) Q_DECL_NOTHROW
+static QT_FUNCTION_TARGET(RDRND) qsizetype qt_random_cpu(void *buffer, qsizetype count) noexcept
 {
     unsigned *ptr = reinterpret_cast<unsigned *>(buffer);
     unsigned *end = ptr + count;
@@ -134,7 +134,7 @@ enum {
 struct QRandomGenerator::SystemGenerator
 {
 #if QT_CONFIG(getentropy)
-    static qsizetype fillBuffer(void *buffer, qsizetype count) Q_DECL_NOTHROW
+    static qsizetype fillBuffer(void *buffer, qsizetype count) noexcept
     {
         // getentropy can read at most 256 bytes, so break the reading
         qsizetype read = 0;
@@ -204,13 +204,13 @@ struct QRandomGenerator::SystemGenerator
     }
 
 #elif defined(Q_OS_WIN) && !defined(Q_OS_WINRT)
-    qsizetype fillBuffer(void *buffer, qsizetype count) Q_DECL_NOTHROW
+    qsizetype fillBuffer(void *buffer, qsizetype count) noexcept
     {
         auto RtlGenRandom = SystemFunction036;
         return RtlGenRandom(buffer, ULONG(count)) ? count: 0;
     }
 #elif defined(Q_OS_WINRT)
-    qsizetype fillBuffer(void *, qsizetype) Q_DECL_NOTHROW
+    qsizetype fillBuffer(void *, qsizetype) noexcept
     {
         // always use the fallback
         return 0;
@@ -242,7 +242,7 @@ struct QRandomGenerator::SystemGenerator
 
 #if defined(Q_OS_WIN)
 static void fallback_update_seed(unsigned) {}
-static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *ptr, qsizetype left) noexcept
 {
     // on Windows, rand_s is a high-quality random number generator
     // and it requires no seeding
@@ -254,14 +254,14 @@ static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
 }
 #elif QT_CONFIG(getentropy)
 static void fallback_update_seed(unsigned) {}
-static void fallback_fill(quint32 *, qsizetype) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *, qsizetype) noexcept
 {
     // no fallback necessary, getentropy cannot fail under normal circumstances
     Q_UNREACHABLE();
 }
 #elif defined(Q_OS_BSD4) && !defined(__GLIBC__)
 static void fallback_update_seed(unsigned) {}
-static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *ptr, qsizetype left) noexcept
 {
     // BSDs have arc4random(4) and these work even in chroot(2)
     arc4random_buf(ptr, left * sizeof(*ptr));
@@ -280,7 +280,7 @@ Q_NEVER_INLINE
 #ifdef Q_CC_GNU
 __attribute__((cold))   // this function is pretty big, so optimize for size
 #endif
-static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *ptr, qsizetype left) noexcept
 {
     quint32 scratch[12];    // see element count below
     quint32 *end = scratch;
@@ -1167,7 +1167,7 @@ QRandomGenerator &QRandomGenerator::operator=(const QRandomGenerator &other)
     return *this;
 }
 
-QRandomGenerator::QRandomGenerator(std::seed_seq &sseq) Q_DECL_NOTHROW
+QRandomGenerator::QRandomGenerator(std::seed_seq &sseq) noexcept
     : type(MersenneTwister)
 {
     Q_ASSERT(this != system());
diff --git a/src/corelib/global/qrandom.h b/src/corelib/global/qrandom.h
index 46d3e0e152..2f72528266 100644
--- a/src/corelib/global/qrandom.h
+++ b/src/corelib/global/qrandom.h
@@ -68,7 +68,7 @@ public:
     QRandomGenerator(const quint32 *seedBuffer, qsizetype len)
         : QRandomGenerator(seedBuffer, seedBuffer + len)
     {}
-    Q_CORE_EXPORT QRandomGenerator(std::seed_seq &sseq) Q_DECL_NOTHROW;
+    Q_CORE_EXPORT QRandomGenerator(std::seed_seq &sseq) noexcept;
     Q_CORE_EXPORT QRandomGenerator(const quint32 *begin, const quint32 *end);
 
     // copy constructor & assignment operator (move unnecessary)
@@ -165,7 +165,7 @@ public:
     typedef quint32 result_type;
     result_type operator()() { return generate(); }
     void seed(quint32 s = 1) { *this = { s }; }
-    void seed(std::seed_seq &sseq) Q_DECL_NOTHROW { *this = { sseq }; }
+    void seed(std::seed_seq &sseq) noexcept { *this = { sseq }; }
     Q_CORE_EXPORT void discard(unsigned long long z);
     static Q_DECL_CONSTEXPR result_type min() { return std::numeric_limits<result_type>::min(); }
     static Q_DECL_CONSTEXPR result_type max() { return std::numeric_limits<result_type>::max(); }
@@ -228,7 +228,7 @@ public:
     QRandomGenerator64(const quint32 *seedBuffer, qsizetype len)
         : QRandomGenerator(seedBuffer, len)
     {}
-    QRandomGenerator64(std::seed_seq &sseq) Q_DECL_NOTHROW
+    QRandomGenerator64(std::seed_seq &sseq) noexcept
         : QRandomGenerator(sseq)
     {}
     QRandomGenerator64(const quint32 *begin, const quint32 *end)
diff --git a/src/corelib/io/qdebug.h b/src/corelib/io/qdebug.h
index 91fde75fa5..ea2d57370d 100644
--- a/src/corelib/io/qdebug.h
+++ b/src/corelib/io/qdebug.h
@@ -116,7 +116,7 @@ public:
     inline QDebug(const QDebug &o):stream(o.stream) { ++stream->ref; }
     inline QDebug &operator=(const QDebug &other);
     ~QDebug();
-    inline void swap(QDebug &other) Q_DECL_NOTHROW { qSwap(stream, other.stream); }
+    inline void swap(QDebug &other) noexcept { qSwap(stream, other.stream); }
 
     QDebug &resetFormat();
 
diff --git a/src/corelib/io/qdir.h b/src/corelib/io/qdir.h
index 9abb833ab1..547ac163c7 100644
--- a/src/corelib/io/qdir.h
+++ b/src/corelib/io/qdir.h
@@ -110,10 +110,10 @@ public:
     QDir &operator=(const QString &path);
 #endif
 #ifdef Q_COMPILER_RVALUE_REFS
-    QDir &operator=(QDir &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QDir &operator=(QDir &&other) noexcept { swap(other); return *this; }
 #endif
 
-    void swap(QDir &other) Q_DECL_NOTHROW
+    void swap(QDir &other) noexcept
     { qSwap(d_ptr, other.d_ptr); }
 
     void setPath(const QString &path);
@@ -190,7 +190,7 @@ public:
 
     static QFileInfoList drives();
 
-    Q_DECL_CONSTEXPR static inline QChar listSeparator() Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR static inline QChar listSeparator() noexcept
     {
 #if defined(Q_OS_WIN)
         return QLatin1Char(';');
diff --git a/src/corelib/io/qfileinfo.h b/src/corelib/io/qfileinfo.h
index baea18fab1..bd9e1d216f 100644
--- a/src/corelib/io/qfileinfo.h
+++ b/src/corelib/io/qfileinfo.h
@@ -68,10 +68,10 @@ public:
 
     QFileInfo &operator=(const QFileInfo &fileinfo);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QFileInfo &operator=(QFileInfo &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QFileInfo &operator=(QFileInfo &&other) noexcept { swap(other); return *this; }
 #endif
 
-    void swap(QFileInfo &other) Q_DECL_NOTHROW
+    void swap(QFileInfo &other) noexcept
     { qSwap(d_ptr, other.d_ptr); }
 
     bool operator==(const QFileInfo &fileinfo) const;
diff --git a/src/corelib/io/qprocess.h b/src/corelib/io/qprocess.h
index a2e3c01f7c..83b7138ff9 100644
--- a/src/corelib/io/qprocess.h
+++ b/src/corelib/io/qprocess.h
@@ -73,11 +73,11 @@ public:
     QProcessEnvironment(const QProcessEnvironment &other);
     ~QProcessEnvironment();
 #ifdef Q_COMPILER_RVALUE_REFS
-    QProcessEnvironment &operator=(QProcessEnvironment && other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QProcessEnvironment &operator=(QProcessEnvironment && other) noexcept { swap(other); return *this; }
 #endif
     QProcessEnvironment &operator=(const QProcessEnvironment &other);
 
-    void swap(QProcessEnvironment &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    void swap(QProcessEnvironment &other) noexcept { qSwap(d, other.d); }
 
     bool operator==(const QProcessEnvironment &other) const;
     inline bool operator!=(const QProcessEnvironment &other) const
diff --git a/src/corelib/io/qstorageinfo.h b/src/corelib/io/qstorageinfo.h
index 4ab7a353ef..addcbb2990 100644
--- a/src/corelib/io/qstorageinfo.h
+++ b/src/corelib/io/qstorageinfo.h
@@ -63,10 +63,10 @@ public:
 
     QStorageInfo &operator=(const QStorageInfo &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QStorageInfo &operator=(QStorageInfo &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QStorageInfo &operator=(QStorageInfo &&other) noexcept { swap(other); return *this; }
 #endif
 
-    inline void swap(QStorageInfo &other) Q_DECL_NOTHROW
+    inline void swap(QStorageInfo &other) noexcept
     { qSwap(d, other.d); }
 
     void setPath(const QString &path);
diff --git a/src/corelib/io/qurl.cpp b/src/corelib/io/qurl.cpp
index 6d82981fd6..b4090f710e 100644
--- a/src/corelib/io/qurl.cpp
+++ b/src/corelib/io/qurl.cpp
@@ -4159,7 +4159,7 @@ QList<QUrl> QUrl::fromStringList(const QStringList &urls, ParsingMode mode)
     \relates QHash
     \since 5.0
 */
-uint qHash(const QUrl &url, uint seed) Q_DECL_NOTHROW
+uint qHash(const QUrl &url, uint seed) noexcept
 {
     if (!url.d)
         return qHash(-1, seed); // the hash of an unset port (-1)
diff --git a/src/corelib/io/qurl.h b/src/corelib/io/qurl.h
index 5062ef7905..70e549c1a9 100644
--- a/src/corelib/io/qurl.h
+++ b/src/corelib/io/qurl.h
@@ -119,7 +119,7 @@ class QTypeInfo<QUrlTwoFlags<E1, E2> > : public QTypeInfoMerger<QUrlTwoFlags<E1,
 
 class QUrl;
 // qHash is a friend, but we can't use default arguments for friends (§8.3.6.4)
-Q_CORE_EXPORT uint qHash(const QUrl &url, uint seed = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT uint qHash(const QUrl &url, uint seed = 0) noexcept;
 
 class Q_CORE_EXPORT QUrl
 {
@@ -183,14 +183,14 @@ public:
     QUrl &operator=(const QString &url);
 #endif
 #ifdef Q_COMPILER_RVALUE_REFS
-    QUrl(QUrl &&other) Q_DECL_NOTHROW : d(other.d)
+    QUrl(QUrl &&other) noexcept : d(other.d)
     { other.d = nullptr; }
-    inline QUrl &operator=(QUrl &&other) Q_DECL_NOTHROW
+    inline QUrl &operator=(QUrl &&other) noexcept
     { qSwap(d, other.d); return *this; }
 #endif
     ~QUrl();
 
-    inline void swap(QUrl &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    inline void swap(QUrl &other) noexcept { qSwap(d, other.d); }
 
     void setUrl(const QString &url, ParsingMode mode = TolerantMode);
     QString url(FormattingOptions options = FormattingOptions(PrettyDecoded)) const;
@@ -361,7 +361,7 @@ public:
     static QList<QUrl> fromStringList(const QStringList &uris, ParsingMode mode = TolerantMode);
 
     static void setIdnWhitelist(const QStringList &);
-    friend Q_CORE_EXPORT uint qHash(const QUrl &url, uint seed) Q_DECL_NOTHROW;
+    friend Q_CORE_EXPORT uint qHash(const QUrl &url, uint seed) noexcept;
 
 private:
     QUrlPrivate *d;
diff --git a/src/corelib/io/qurlquery.cpp b/src/corelib/io/qurlquery.cpp
index 10c3f836c8..d76107abfd 100644
--- a/src/corelib/io/qurlquery.cpp
+++ b/src/corelib/io/qurlquery.cpp
@@ -434,7 +434,7 @@ bool QUrlQuery::operator ==(const QUrlQuery &other) const
     Returns the hash value for \a key,
     using \a seed to seed the calculation.
 */
-uint qHash(const QUrlQuery &key, uint seed) Q_DECL_NOTHROW
+uint qHash(const QUrlQuery &key, uint seed) noexcept
 {
     if (const QUrlQueryPrivate *d = key.d) {
         QtPrivate::QHashCombine hash;
diff --git a/src/corelib/io/qurlquery.h b/src/corelib/io/qurlquery.h
index e3688aae2c..2a497dc8da 100644
--- a/src/corelib/io/qurlquery.h
+++ b/src/corelib/io/qurlquery.h
@@ -52,7 +52,7 @@
 
 QT_BEGIN_NAMESPACE
 
-Q_CORE_EXPORT uint qHash(const QUrlQuery &key, uint seed = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT uint qHash(const QUrlQuery &key, uint seed = 0) noexcept;
 
 class QUrlQueryPrivate;
 class Q_CORE_EXPORT QUrlQuery
@@ -71,7 +71,7 @@ public:
     QUrlQuery(const QUrlQuery &other);
     QUrlQuery &operator=(const QUrlQuery &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QUrlQuery &operator=(QUrlQuery &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QUrlQuery &operator=(QUrlQuery &&other) noexcept { swap(other); return *this; }
 #endif
     ~QUrlQuery();
 
@@ -79,7 +79,7 @@ public:
     bool operator!=(const QUrlQuery &other) const
     { return !(*this == other); }
 
-    void swap(QUrlQuery &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    void swap(QUrlQuery &other) noexcept { qSwap(d, other.d); }
 
     bool isEmpty() const;
     bool isDetached() const;
@@ -111,7 +111,7 @@ public:
 
 private:
     friend class QUrl;
-    friend Q_CORE_EXPORT uint qHash(const QUrlQuery &key, uint seed) Q_DECL_NOTHROW;
+    friend Q_CORE_EXPORT uint qHash(const QUrlQuery &key, uint seed) noexcept;
     QSharedDataPointer<QUrlQueryPrivate> d;
 public:
     typedef QSharedDataPointer<QUrlQueryPrivate> DataPtr;
diff --git a/src/corelib/io/qurlrecode.cpp b/src/corelib/io/qurlrecode.cpp
index 443ae18b21..f23480c755 100644
--- a/src/corelib/io/qurlrecode.cpp
+++ b/src/corelib/io/qurlrecode.cpp
@@ -692,7 +692,7 @@ qt_urlRecode(QString &appendTo, const QChar *begin, const QChar *end,
 }
 
 // qstring.cpp
-bool qt_is_ascii(const char *&ptr, const char *end) Q_DECL_NOTHROW;
+bool qt_is_ascii(const char *&ptr, const char *end) noexcept;
 
 /*!
     \internal
diff --git a/src/corelib/itemmodels/qabstractitemmodel.h b/src/corelib/itemmodels/qabstractitemmodel.h
index c34876d1d6..496f583c22 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.h
+++ b/src/corelib/itemmodels/qabstractitemmodel.h
@@ -57,12 +57,12 @@ class Q_CORE_EXPORT QModelIndex
 {
     friend class QAbstractItemModel;
 public:
-    Q_DECL_CONSTEXPR inline QModelIndex() Q_DECL_NOTHROW : r(-1), c(-1), i(0), m(nullptr) {}
+    Q_DECL_CONSTEXPR inline QModelIndex() noexcept : r(-1), c(-1), i(0), m(nullptr) {}
     // compiler-generated copy/move ctors/assignment operators are fine!
-    Q_DECL_CONSTEXPR inline int row() const Q_DECL_NOTHROW { return r; }
-    Q_DECL_CONSTEXPR inline int column() const Q_DECL_NOTHROW { return c; }
-    Q_DECL_CONSTEXPR inline quintptr internalId() const Q_DECL_NOTHROW { return i; }
-    inline void *internalPointer() const Q_DECL_NOTHROW { return reinterpret_cast<void*>(i); }
+    Q_DECL_CONSTEXPR inline int row() const noexcept { return r; }
+    Q_DECL_CONSTEXPR inline int column() const noexcept { return c; }
+    Q_DECL_CONSTEXPR inline quintptr internalId() const noexcept { return i; }
+    inline void *internalPointer() const noexcept { return reinterpret_cast<void*>(i); }
     inline QModelIndex parent() const;
     inline QModelIndex sibling(int row, int column) const;
     inline QModelIndex siblingAtColumn(int column) const;
@@ -72,13 +72,13 @@ public:
 #endif
     inline QVariant data(int role = Qt::DisplayRole) const;
     inline Qt::ItemFlags flags() const;
-    Q_DECL_CONSTEXPR inline const QAbstractItemModel *model() const Q_DECL_NOTHROW { return m; }
-    Q_DECL_CONSTEXPR inline bool isValid() const Q_DECL_NOTHROW { return (r >= 0) && (c >= 0) && (m != nullptr); }
-    Q_DECL_CONSTEXPR inline bool operator==(const QModelIndex &other) const Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR inline const QAbstractItemModel *model() const noexcept { return m; }
+    Q_DECL_CONSTEXPR inline bool isValid() const noexcept { return (r >= 0) && (c >= 0) && (m != nullptr); }
+    Q_DECL_CONSTEXPR inline bool operator==(const QModelIndex &other) const noexcept
         { return (other.r == r) && (other.i == i) && (other.c == c) && (other.m == m); }
-    Q_DECL_CONSTEXPR inline bool operator!=(const QModelIndex &other) const Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR inline bool operator!=(const QModelIndex &other) const noexcept
         { return !(*this == other); }
-    Q_DECL_CONSTEXPR inline bool operator<(const QModelIndex &other) const Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR inline bool operator<(const QModelIndex &other) const noexcept
         {
             return  r <  other.r
                 || (r == other.r && (c <  other.c
@@ -86,9 +86,9 @@ public:
                                                   || (i == other.i && std::less<const QAbstractItemModel *>()(m, other.m))))));
         }
 private:
-    inline QModelIndex(int arow, int acolumn, void *ptr, const QAbstractItemModel *amodel) Q_DECL_NOTHROW
+    inline QModelIndex(int arow, int acolumn, void *ptr, const QAbstractItemModel *amodel) noexcept
         : r(arow), c(acolumn), i(reinterpret_cast<quintptr>(ptr)), m(amodel) {}
-    Q_DECL_CONSTEXPR inline QModelIndex(int arow, int acolumn, quintptr id, const QAbstractItemModel *amodel) Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR inline QModelIndex(int arow, int acolumn, quintptr id, const QAbstractItemModel *amodel) noexcept
         : r(arow), c(acolumn), i(id), m(amodel) {}
     int r, c;
     quintptr i;
@@ -103,7 +103,7 @@ Q_CORE_EXPORT QDebug operator<<(QDebug, const QModelIndex &);
 class QPersistentModelIndexData;
 
 // qHash is a friend, but we can't use default arguments for friends (§8.3.6.4)
-uint qHash(const QPersistentModelIndex &index, uint seed = 0) Q_DECL_NOTHROW;
+uint qHash(const QPersistentModelIndex &index, uint seed = 0) noexcept;
 
 class Q_CORE_EXPORT QPersistentModelIndex
 {
@@ -118,12 +118,12 @@ public:
     { return !operator==(other); }
     QPersistentModelIndex &operator=(const QPersistentModelIndex &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QPersistentModelIndex(QPersistentModelIndex &&other) Q_DECL_NOTHROW
+    inline QPersistentModelIndex(QPersistentModelIndex &&other) noexcept
         : d(other.d) { other.d = nullptr; }
-    inline QPersistentModelIndex &operator=(QPersistentModelIndex &&other) Q_DECL_NOTHROW
+    inline QPersistentModelIndex &operator=(QPersistentModelIndex &&other) noexcept
     { qSwap(d, other.d); return *this; }
 #endif
-    inline void swap(QPersistentModelIndex &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    inline void swap(QPersistentModelIndex &other) noexcept { qSwap(d, other.d); }
     bool operator==(const QModelIndex &other) const;
     bool operator!=(const QModelIndex &other) const;
     QPersistentModelIndex &operator=(const QModelIndex &other);
@@ -143,14 +143,14 @@ public:
     bool isValid() const;
 private:
     QPersistentModelIndexData *d;
-    friend uint qHash(const QPersistentModelIndex &, uint seed) Q_DECL_NOTHROW;
+    friend uint qHash(const QPersistentModelIndex &, uint seed) noexcept;
 #ifndef QT_NO_DEBUG_STREAM
     friend Q_CORE_EXPORT QDebug operator<<(QDebug, const QPersistentModelIndex &);
 #endif
 };
 Q_DECLARE_SHARED(QPersistentModelIndex)
 
-inline uint qHash(const QPersistentModelIndex &index, uint seed) Q_DECL_NOTHROW
+inline uint qHash(const QPersistentModelIndex &index, uint seed) noexcept
 { return qHash(index.d, seed); }
 
 
@@ -464,7 +464,7 @@ inline QVariant QModelIndex::data(int arole) const
 inline Qt::ItemFlags QModelIndex::flags() const
 { return m ? m->flags(*this) : Qt::ItemFlags(); }
 
-inline uint qHash(const QModelIndex &index) Q_DECL_NOTHROW
+inline uint qHash(const QModelIndex &index) noexcept
 { return uint((uint(index.row()) << 4) + index.column() + index.internalId()); }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/itemmodels/qitemselectionmodel.h b/src/corelib/itemmodels/qitemselectionmodel.h
index 1c924053a5..e5cd24817b 100644
--- a/src/corelib/itemmodels/qitemselectionmodel.h
+++ b/src/corelib/itemmodels/qitemselectionmodel.h
@@ -61,9 +61,9 @@ public:
     inline QItemSelectionRange(const QItemSelectionRange &other)
         : tl(other.tl), br(other.br) {}
 # ifdef Q_COMPILER_RVALUE_REFS
-    QItemSelectionRange(QItemSelectionRange &&other) Q_DECL_NOTHROW
+    QItemSelectionRange(QItemSelectionRange &&other) noexcept
         : tl(std::move(other.tl)), br(std::move(other.br)) {}
-    QItemSelectionRange &operator=(QItemSelectionRange &&other) Q_DECL_NOTHROW
+    QItemSelectionRange &operator=(QItemSelectionRange &&other) noexcept
     { tl = std::move(other.tl); br = std::move(other.br); return *this; }
 # endif
     QItemSelectionRange &operator=(const QItemSelectionRange &other)
@@ -72,7 +72,7 @@ public:
     QItemSelectionRange(const QModelIndex &topL, const QModelIndex &bottomR) : tl(topL), br(bottomR) {}
     explicit QItemSelectionRange(const QModelIndex &index) : tl(index), br(tl) {}
 
-    void swap(QItemSelectionRange &other) Q_DECL_NOTHROW
+    void swap(QItemSelectionRange &other) noexcept
     {
         qSwap(tl, other.tl);
         qSwap(br, other.br);
@@ -249,7 +249,7 @@ Q_TEMPLATE_EXTERN template class Q_CORE_EXPORT QList<QItemSelectionRange>;
 class Q_CORE_EXPORT QItemSelection : public QList<QItemSelectionRange>
 {
 public:
-    QItemSelection() Q_DECL_NOTHROW : QList<QItemSelectionRange>() {}
+    QItemSelection() noexcept : QList<QItemSelectionRange>() {}
     QItemSelection(const QModelIndex &topLeft, const QModelIndex &bottomRight);
 
     // reusing QList::swap() here is OK!
diff --git a/src/corelib/kernel/qcore_unix_p.h b/src/corelib/kernel/qcore_unix_p.h
index 32ef6408c2..7f58813535 100644
--- a/src/corelib/kernel/qcore_unix_p.h
+++ b/src/corelib/kernel/qcore_unix_p.h
@@ -347,7 +347,7 @@ static inline pid_t qt_safe_waitpid(pid_t pid, int *status, int options)
 #endif
 
 // in qelapsedtimer_mac.cpp or qtimestamp_unix.cpp
-timespec qt_gettime() Q_DECL_NOTHROW;
+timespec qt_gettime() noexcept;
 void qt_nanosleep(timespec amount);
 QByteArray qt_readlink(const char *path);
 
diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index 5da33a5aae..038de264cb 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -369,7 +369,7 @@ uint QCoreApplicationPrivate::attribs =
     (1 << Qt::AA_SynthesizeMouseForUnhandledTabletEvents);
 
 struct QCoreApplicationData {
-    QCoreApplicationData() Q_DECL_NOTHROW {
+    QCoreApplicationData() noexcept {
         applicationNameSet = false;
         applicationVersionSet = false;
     }
diff --git a/src/corelib/kernel/qcoreevent.cpp b/src/corelib/kernel/qcoreevent.cpp
index cacbb1e495..aabd32b4a8 100644
--- a/src/corelib/kernel/qcoreevent.cpp
+++ b/src/corelib/kernel/qcoreevent.cpp
@@ -421,7 +421,7 @@ struct QBasicAtomicBitField {
     QBasicAtomicInteger<uint> next;
     QBasicAtomicInteger<uint> data[NumInts];
 
-    bool allocateSpecific(int which) Q_DECL_NOTHROW
+    bool allocateSpecific(int which) noexcept
     {
         QBasicAtomicInteger<uint> &entry = data[which / BitsPerInt];
         const uint old = entry.load();
@@ -437,7 +437,7 @@ struct QBasicAtomicBitField {
         // loop.
     }
 
-    int allocateNext() Q_DECL_NOTHROW
+    int allocateNext() noexcept
     {
         // Unroll loop to iterate over ints, then bits? Would save
         // potentially a lot of cmpxchgs, because we can scan the
@@ -463,7 +463,7 @@ typedef QBasicAtomicBitField<QEvent::MaxUser - QEvent::User + 1> UserEventTypeRe
 
 static UserEventTypeRegistry userEventTypeRegistry;
 
-static inline int registerEventTypeZeroBased(int id) Q_DECL_NOTHROW
+static inline int registerEventTypeZeroBased(int id) noexcept
 {
     // if the type hint hasn't been registered yet, take it:
     if (id < UserEventTypeRegistry::NumBits && id >= 0 && userEventTypeRegistry.allocateSpecific(id))
@@ -486,7 +486,7 @@ static inline int registerEventTypeZeroBased(int id) Q_DECL_NOTHROW
     Returns -1 if all available values are already taken or the
     program is shutting down.
 */
-int QEvent::registerEventType(int hint) Q_DECL_NOTHROW
+int QEvent::registerEventType(int hint) noexcept
 {
     const int result = registerEventTypeZeroBased(QEvent::MaxUser - hint);
     return result < 0 ? -1 : QEvent::MaxUser - result ;
diff --git a/src/corelib/kernel/qcoreevent.h b/src/corelib/kernel/qcoreevent.h
index ac974ba411..05af1a6132 100644
--- a/src/corelib/kernel/qcoreevent.h
+++ b/src/corelib/kernel/qcoreevent.h
@@ -307,7 +307,7 @@ public:
     inline void accept() { m_accept = true; }
     inline void ignore() { m_accept = false; }
 
-    static int registerEventType(int hint = -1) Q_DECL_NOTHROW;
+    static int registerEventType(int hint = -1) noexcept;
 
 protected:
     QEventPrivate *d;
diff --git a/src/corelib/kernel/qdeadlinetimer.cpp b/src/corelib/kernel/qdeadlinetimer.cpp
index 6aa886cfe1..e0d9d9de73 100644
--- a/src/corelib/kernel/qdeadlinetimer.cpp
+++ b/src/corelib/kernel/qdeadlinetimer.cpp
@@ -188,7 +188,7 @@ Q_DECL_CONST_FUNCTION static inline QPair<qint64, qint64> toSecsAndNSecs(qint64
 
     \sa hasExpired(), isForever(), remainingTime(), setRemainingTime()
 */
-QDeadlineTimer::QDeadlineTimer(qint64 msecs, Qt::TimerType type) Q_DECL_NOTHROW
+QDeadlineTimer::QDeadlineTimer(qint64 msecs, Qt::TimerType type) noexcept
     : t2(0)
 {
     setRemainingTime(msecs, type);
@@ -260,7 +260,7 @@ QDeadlineTimer::QDeadlineTimer(qint64 msecs, Qt::TimerType type) Q_DECL_NOTHROW
 
     \sa setPreciseRemainingTime(), hasExpired(), isForever(), remainingTime()
 */
-void QDeadlineTimer::setRemainingTime(qint64 msecs, Qt::TimerType timerType) Q_DECL_NOTHROW
+void QDeadlineTimer::setRemainingTime(qint64 msecs, Qt::TimerType timerType) noexcept
 {
     if (msecs == -1)
         *this = QDeadlineTimer(Forever, timerType);
@@ -279,7 +279,7 @@ void QDeadlineTimer::setRemainingTime(qint64 msecs, Qt::TimerType timerType) Q_D
 
     \sa setRemainingTime(), hasExpired(), isForever(), remainingTime()
 */
-void QDeadlineTimer::setPreciseRemainingTime(qint64 secs, qint64 nsecs, Qt::TimerType timerType) Q_DECL_NOTHROW
+void QDeadlineTimer::setPreciseRemainingTime(qint64 secs, qint64 nsecs, Qt::TimerType timerType) noexcept
 {
     if (secs == -1) {
         *this = QDeadlineTimer(Forever, timerType);
@@ -342,7 +342,7 @@ void QDeadlineTimer::setPreciseRemainingTime(qint64 secs, qint64 nsecs, Qt::Time
 
     \sa isForever(), remainingTime()
 */
-bool QDeadlineTimer::hasExpired() const Q_DECL_NOTHROW
+bool QDeadlineTimer::hasExpired() const noexcept
 {
     if (isForever())
         return false;
@@ -389,7 +389,7 @@ void QDeadlineTimer::setTimerType(Qt::TimerType timerType)
 
     \sa remainingTimeNSecs(), isForever(), hasExpired()
 */
-qint64 QDeadlineTimer::remainingTime() const Q_DECL_NOTHROW
+qint64 QDeadlineTimer::remainingTime() const noexcept
 {
     qint64 ns = remainingTimeNSecs();
     return ns <= 0 ? ns : (ns + 999999) / (1000 * 1000);
@@ -403,7 +403,7 @@ qint64 QDeadlineTimer::remainingTime() const Q_DECL_NOTHROW
 
     \sa remainingTime(), isForever(), hasExpired()
 */
-qint64 QDeadlineTimer::remainingTimeNSecs() const Q_DECL_NOTHROW
+qint64 QDeadlineTimer::remainingTimeNSecs() const noexcept
 {
     if (isForever())
         return -1;
@@ -416,7 +416,7 @@ qint64 QDeadlineTimer::remainingTimeNSecs() const Q_DECL_NOTHROW
     Same as remainingTimeNSecs, but may return negative remaining times. Does
     not deal with Forever.
 */
-qint64 QDeadlineTimer::rawRemainingTimeNSecs() const Q_DECL_NOTHROW
+qint64 QDeadlineTimer::rawRemainingTimeNSecs() const noexcept
 {
     QDeadlineTimer now = current(timerType());
     if (QDeadlineTimerNanosecondsInT2)
@@ -444,7 +444,7 @@ qint64 QDeadlineTimer::rawRemainingTimeNSecs() const Q_DECL_NOTHROW
 
     \sa remainingTime(), deadlineNSecs(), setDeadline()
 */
-qint64 QDeadlineTimer::deadline() const Q_DECL_NOTHROW
+qint64 QDeadlineTimer::deadline() const noexcept
 {
     if (isForever())
         return t1;
@@ -471,7 +471,7 @@ qint64 QDeadlineTimer::deadline() const Q_DECL_NOTHROW
 
     \sa remainingTime(), deadlineNSecs()
 */
-qint64 QDeadlineTimer::deadlineNSecs() const Q_DECL_NOTHROW
+qint64 QDeadlineTimer::deadlineNSecs() const noexcept
 {
     if (isForever())
         return t1;
@@ -492,7 +492,7 @@ qint64 QDeadlineTimer::deadlineNSecs() const Q_DECL_NOTHROW
 
     \sa setPreciseDeadline(), deadline(), deadlineNSecs(), setRemainingTime()
 */
-void QDeadlineTimer::setDeadline(qint64 msecs, Qt::TimerType timerType) Q_DECL_NOTHROW
+void QDeadlineTimer::setDeadline(qint64 msecs, Qt::TimerType timerType) noexcept
 {
     if (msecs == (std::numeric_limits<qint64>::max)()) {
         setPreciseDeadline(msecs, 0, timerType);    // msecs == MAX implies Forever
@@ -513,7 +513,7 @@ void QDeadlineTimer::setDeadline(qint64 msecs, Qt::TimerType timerType) Q_DECL_N
 
     \sa setDeadline(), deadline(), deadlineNSecs(), setRemainingTime()
 */
-void QDeadlineTimer::setPreciseDeadline(qint64 secs, qint64 nsecs, Qt::TimerType timerType) Q_DECL_NOTHROW
+void QDeadlineTimer::setPreciseDeadline(qint64 secs, qint64 nsecs, Qt::TimerType timerType) noexcept
 {
     type = timerType;
     if (secs == (std::numeric_limits<qint64>::max)() || nsecs == (std::numeric_limits<qint64>::max)()) {
@@ -534,7 +534,7 @@ void QDeadlineTimer::setPreciseDeadline(qint64 secs, qint64 nsecs, Qt::TimerType
     \note if \a dt was created as expired, its deadline is indeterminate and
     adding an amount of time may or may not cause it to become unexpired.
 */
-QDeadlineTimer QDeadlineTimer::addNSecs(QDeadlineTimer dt, qint64 nsecs) Q_DECL_NOTHROW
+QDeadlineTimer QDeadlineTimer::addNSecs(QDeadlineTimer dt, qint64 nsecs) noexcept
 {
     if (dt.isForever() || nsecs == (std::numeric_limits<qint64>::max)()) {
         dt = QDeadlineTimer(Forever, dt.timerType());
diff --git a/src/corelib/kernel/qdeadlinetimer.h b/src/corelib/kernel/qdeadlinetimer.h
index 1a4ee04a96..8032ee9018 100644
--- a/src/corelib/kernel/qdeadlinetimer.h
+++ b/src/corelib/kernel/qdeadlinetimer.h
@@ -63,49 +63,49 @@ class Q_CORE_EXPORT QDeadlineTimer
 public:
     enum ForeverConstant { Forever };
 
-    Q_DECL_CONSTEXPR QDeadlineTimer(Qt::TimerType type_ = Qt::CoarseTimer) Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR QDeadlineTimer(Qt::TimerType type_ = Qt::CoarseTimer) noexcept
         : t1(0), t2(0), type(type_) {}
-    Q_DECL_CONSTEXPR QDeadlineTimer(ForeverConstant, Qt::TimerType type_ = Qt::CoarseTimer) Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR QDeadlineTimer(ForeverConstant, Qt::TimerType type_ = Qt::CoarseTimer) noexcept
         : t1(std::numeric_limits<qint64>::max()), t2(0), type(type_) {}
-    explicit QDeadlineTimer(qint64 msecs, Qt::TimerType type = Qt::CoarseTimer) Q_DECL_NOTHROW;
+    explicit QDeadlineTimer(qint64 msecs, Qt::TimerType type = Qt::CoarseTimer) noexcept;
 
-    void swap(QDeadlineTimer &other) Q_DECL_NOTHROW
+    void swap(QDeadlineTimer &other) noexcept
     { qSwap(t1, other.t1); qSwap(t2, other.t2); qSwap(type, other.type); }
 
-    Q_DECL_CONSTEXPR bool isForever() const Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR bool isForever() const noexcept
     { return t1 == (std::numeric_limits<qint64>::max)(); }
-    bool hasExpired() const Q_DECL_NOTHROW;
+    bool hasExpired() const noexcept;
 
-    Qt::TimerType timerType() const Q_DECL_NOTHROW
+    Qt::TimerType timerType() const noexcept
     { return Qt::TimerType(type & 0xff); }
     void setTimerType(Qt::TimerType type);
 
-    qint64 remainingTime() const Q_DECL_NOTHROW;
-    qint64 remainingTimeNSecs() const Q_DECL_NOTHROW;
-    void setRemainingTime(qint64 msecs, Qt::TimerType type = Qt::CoarseTimer) Q_DECL_NOTHROW;
+    qint64 remainingTime() const noexcept;
+    qint64 remainingTimeNSecs() const noexcept;
+    void setRemainingTime(qint64 msecs, Qt::TimerType type = Qt::CoarseTimer) noexcept;
     void setPreciseRemainingTime(qint64 secs, qint64 nsecs = 0,
-                                 Qt::TimerType type = Qt::CoarseTimer) Q_DECL_NOTHROW;
+                                 Qt::TimerType type = Qt::CoarseTimer) noexcept;
 
-    qint64 deadline() const Q_DECL_NOTHROW Q_DECL_PURE_FUNCTION;
-    qint64 deadlineNSecs() const Q_DECL_NOTHROW Q_DECL_PURE_FUNCTION;
-    void setDeadline(qint64 msecs, Qt::TimerType timerType = Qt::CoarseTimer) Q_DECL_NOTHROW;
+    qint64 deadline() const noexcept Q_DECL_PURE_FUNCTION;
+    qint64 deadlineNSecs() const noexcept Q_DECL_PURE_FUNCTION;
+    void setDeadline(qint64 msecs, Qt::TimerType timerType = Qt::CoarseTimer) noexcept;
     void setPreciseDeadline(qint64 secs, qint64 nsecs = 0,
-                            Qt::TimerType type = Qt::CoarseTimer) Q_DECL_NOTHROW;
+                            Qt::TimerType type = Qt::CoarseTimer) noexcept;
 
-    static QDeadlineTimer addNSecs(QDeadlineTimer dt, qint64 nsecs) Q_DECL_NOTHROW Q_DECL_PURE_FUNCTION;
-    static QDeadlineTimer current(Qt::TimerType timerType = Qt::CoarseTimer) Q_DECL_NOTHROW;
+    static QDeadlineTimer addNSecs(QDeadlineTimer dt, qint64 nsecs) noexcept Q_DECL_PURE_FUNCTION;
+    static QDeadlineTimer current(Qt::TimerType timerType = Qt::CoarseTimer) noexcept;
 
-    friend bool operator==(QDeadlineTimer d1, QDeadlineTimer d2) Q_DECL_NOTHROW
+    friend bool operator==(QDeadlineTimer d1, QDeadlineTimer d2) noexcept
     { return d1.t1 == d2.t1 && d1.t2 == d2.t2; }
-    friend bool operator!=(QDeadlineTimer d1, QDeadlineTimer d2) Q_DECL_NOTHROW
+    friend bool operator!=(QDeadlineTimer d1, QDeadlineTimer d2) noexcept
     { return !(d1 == d2); }
-    friend bool operator<(QDeadlineTimer d1, QDeadlineTimer d2) Q_DECL_NOTHROW
+    friend bool operator<(QDeadlineTimer d1, QDeadlineTimer d2) noexcept
     { return d1.t1 < d2.t1 || (d1.t1 == d2.t1 && d1.t2 < d2.t2); }
-    friend bool operator<=(QDeadlineTimer d1, QDeadlineTimer d2) Q_DECL_NOTHROW
+    friend bool operator<=(QDeadlineTimer d1, QDeadlineTimer d2) noexcept
     { return d1 == d2 || d1 < d2; }
-    friend bool operator>(QDeadlineTimer d1, QDeadlineTimer d2) Q_DECL_NOTHROW
+    friend bool operator>(QDeadlineTimer d1, QDeadlineTimer d2) noexcept
     { return d2 < d1; }
-    friend bool operator>=(QDeadlineTimer d1, QDeadlineTimer d2) Q_DECL_NOTHROW
+    friend bool operator>=(QDeadlineTimer d1, QDeadlineTimer d2) noexcept
     { return !(d1 < d2); }
 
     friend QDeadlineTimer operator+(QDeadlineTimer dt, qint64 msecs)
@@ -160,7 +160,7 @@ public:
             setPreciseRemainingTime(0, std::chrono::nanoseconds(remaining).count(), type_);
     }
 
-    std::chrono::nanoseconds remainingTimeAsDuration() const Q_DECL_NOTHROW
+    std::chrono::nanoseconds remainingTimeAsDuration() const noexcept
     {
         if (isForever())
             return std::chrono::nanoseconds::max();
@@ -186,7 +186,7 @@ private:
     unsigned t2;
     unsigned type;
 
-    qint64 rawRemainingTimeNSecs() const Q_DECL_NOTHROW;
+    qint64 rawRemainingTimeNSecs() const noexcept;
 
 public:
     // This is not a public function, it's here only for Qt's internal convenience...
diff --git a/src/corelib/kernel/qelapsedtimer.cpp b/src/corelib/kernel/qelapsedtimer.cpp
index e578b5b8b3..adb554b624 100644
--- a/src/corelib/kernel/qelapsedtimer.cpp
+++ b/src/corelib/kernel/qelapsedtimer.cpp
@@ -236,7 +236,7 @@ static const qint64 invalidData = Q_INT64_C(0x8000000000000000);
 
     \sa isValid(), start(), restart()
 */
-void QElapsedTimer::invalidate() Q_DECL_NOTHROW
+void QElapsedTimer::invalidate() noexcept
 {
      t1 = t2 = invalidData;
 }
@@ -247,7 +247,7 @@ void QElapsedTimer::invalidate() Q_DECL_NOTHROW
 
     \sa invalidate(), start(), restart()
 */
-bool QElapsedTimer::isValid() const Q_DECL_NOTHROW
+bool QElapsedTimer::isValid() const noexcept
 {
     return t1 != invalidData && t2 != invalidData;
 }
@@ -260,7 +260,7 @@ bool QElapsedTimer::isValid() const Q_DECL_NOTHROW
 
     \sa elapsed(), QDeadlineTimer
 */
-bool QElapsedTimer::hasExpired(qint64 timeout) const Q_DECL_NOTHROW
+bool QElapsedTimer::hasExpired(qint64 timeout) const noexcept
 {
     // if timeout is -1, quint64(timeout) is LLINT_MAX, so this will be
     // considered as never expired
diff --git a/src/corelib/kernel/qelapsedtimer.h b/src/corelib/kernel/qelapsedtimer.h
index 7954b41bf4..873847f6b6 100644
--- a/src/corelib/kernel/qelapsedtimer.h
+++ b/src/corelib/kernel/qelapsedtimer.h
@@ -62,28 +62,28 @@ public:
     {
     }
 
-    static ClockType clockType() Q_DECL_NOTHROW;
-    static bool isMonotonic() Q_DECL_NOTHROW;
+    static ClockType clockType() noexcept;
+    static bool isMonotonic() noexcept;
 
-    void start() Q_DECL_NOTHROW;
-    qint64 restart() Q_DECL_NOTHROW;
-    void invalidate() Q_DECL_NOTHROW;
-    bool isValid() const Q_DECL_NOTHROW;
+    void start() noexcept;
+    qint64 restart() noexcept;
+    void invalidate() noexcept;
+    bool isValid() const noexcept;
 
-    qint64 nsecsElapsed() const Q_DECL_NOTHROW;
-    qint64 elapsed() const Q_DECL_NOTHROW;
-    bool hasExpired(qint64 timeout) const Q_DECL_NOTHROW;
+    qint64 nsecsElapsed() const noexcept;
+    qint64 elapsed() const noexcept;
+    bool hasExpired(qint64 timeout) const noexcept;
 
-    qint64 msecsSinceReference() const Q_DECL_NOTHROW;
-    qint64 msecsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW;
-    qint64 secsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW;
+    qint64 msecsSinceReference() const noexcept;
+    qint64 msecsTo(const QElapsedTimer &other) const noexcept;
+    qint64 secsTo(const QElapsedTimer &other) const noexcept;
 
-    bool operator==(const QElapsedTimer &other) const Q_DECL_NOTHROW
+    bool operator==(const QElapsedTimer &other) const noexcept
     { return t1 == other.t1 && t2 == other.t2; }
-    bool operator!=(const QElapsedTimer &other) const Q_DECL_NOTHROW
+    bool operator!=(const QElapsedTimer &other) const noexcept
     { return !(*this == other); }
 
-    friend bool Q_CORE_EXPORT operator<(const QElapsedTimer &v1, const QElapsedTimer &v2) Q_DECL_NOTHROW;
+    friend bool Q_CORE_EXPORT operator<(const QElapsedTimer &v1, const QElapsedTimer &v2) noexcept;
 
 private:
     qint64 t1;
diff --git a/src/corelib/kernel/qelapsedtimer_generic.cpp b/src/corelib/kernel/qelapsedtimer_generic.cpp
index fdeb385188..fe959e3c94 100644
--- a/src/corelib/kernel/qelapsedtimer_generic.cpp
+++ b/src/corelib/kernel/qelapsedtimer_generic.cpp
@@ -48,7 +48,7 @@ QT_BEGIN_NAMESPACE
 
     \sa isMonotonic()
 */
-QElapsedTimer::ClockType QElapsedTimer::clockType() Q_DECL_NOTHROW
+QElapsedTimer::ClockType QElapsedTimer::clockType() noexcept
 {
     return SystemTime;
 }
@@ -60,7 +60,7 @@ QElapsedTimer::ClockType QElapsedTimer::clockType() Q_DECL_NOTHROW
 
     \sa clockType(), QElapsedTimer::ClockType
 */
-bool QElapsedTimer::isMonotonic() Q_DECL_NOTHROW
+bool QElapsedTimer::isMonotonic() noexcept
 {
     return false;
 }
@@ -75,7 +75,7 @@ bool QElapsedTimer::isMonotonic() Q_DECL_NOTHROW
 
     \sa restart(), invalidate(), elapsed()
 */
-void QElapsedTimer::start() Q_DECL_NOTHROW
+void QElapsedTimer::start() noexcept
 {
     restart();
 }
@@ -97,7 +97,7 @@ void QElapsedTimer::start() Q_DECL_NOTHROW
 
     \sa start(), invalidate(), elapsed(), isValid()
 */
-qint64 QElapsedTimer::restart() Q_DECL_NOTHROW
+qint64 QElapsedTimer::restart() noexcept
 {
     qint64 old = t1;
     t1 = QDateTime::currentMSecsSinceEpoch();
@@ -118,7 +118,7 @@ qint64 QElapsedTimer::restart() Q_DECL_NOTHROW
 
     \sa start(), restart(), hasExpired(), invalidate()
 */
-qint64 QElapsedTimer::nsecsElapsed() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::nsecsElapsed() const noexcept
 {
     return elapsed() * 1000000;
 }
@@ -132,7 +132,7 @@ qint64 QElapsedTimer::nsecsElapsed() const Q_DECL_NOTHROW
 
     \sa start(), restart(), hasExpired(), isValid(), invalidate()
 */
-qint64 QElapsedTimer::elapsed() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::elapsed() const noexcept
 {
     return QDateTime::currentMSecsSinceEpoch() - t1;
 }
@@ -152,7 +152,7 @@ qint64 QElapsedTimer::elapsed() const Q_DECL_NOTHROW
 
     \sa clockType(), elapsed()
 */
-qint64 QElapsedTimer::msecsSinceReference() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::msecsSinceReference() const noexcept
 {
     return t1;
 }
@@ -167,7 +167,7 @@ qint64 QElapsedTimer::msecsSinceReference() const Q_DECL_NOTHROW
 
     \sa secsTo(), elapsed()
 */
-qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW
+qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const noexcept
 {
     qint64 diff = other.t1 - t1;
     return diff;
@@ -183,7 +183,7 @@ qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW
 
     \sa msecsTo(), elapsed()
 */
-qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW
+qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const noexcept
 {
     return msecsTo(other) / 1000;
 }
@@ -197,12 +197,12 @@ qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW
     and the other isn't. However, two invalid timers are equal and thus this
     function will return false.
 */
-bool operator<(const QElapsedTimer &v1, const QElapsedTimer &v2) Q_DECL_NOTHROW
+bool operator<(const QElapsedTimer &v1, const QElapsedTimer &v2) noexcept
 {
     return v1.t1 < v2.t1;
 }
 
-QDeadlineTimer QDeadlineTimer::current(Qt::TimerType timerType) Q_DECL_NOTHROW
+QDeadlineTimer QDeadlineTimer::current(Qt::TimerType timerType) noexcept
 {
     QDeadlineTimer result;
     result.t1 = QDateTime::currentMSecsSinceEpoch() * 1000 * 1000;
diff --git a/src/corelib/kernel/qelapsedtimer_mac.cpp b/src/corelib/kernel/qelapsedtimer_mac.cpp
index 7490693991..5370cf7b3d 100644
--- a/src/corelib/kernel/qelapsedtimer_mac.cpp
+++ b/src/corelib/kernel/qelapsedtimer_mac.cpp
@@ -58,12 +58,12 @@ typedef __int128_t LargeInt;
 typedef qint64 LargeInt;
 #endif
 
-QElapsedTimer::ClockType QElapsedTimer::clockType() Q_DECL_NOTHROW
+QElapsedTimer::ClockType QElapsedTimer::clockType() noexcept
 {
     return MachAbsoluteTime;
 }
 
-bool QElapsedTimer::isMonotonic() Q_DECL_NOTHROW
+bool QElapsedTimer::isMonotonic() noexcept
 {
     return true;
 }
@@ -87,7 +87,7 @@ static qint64 absoluteToMSecs(qint64 cpuTime)
     return absoluteToNSecs(cpuTime) / 1000000;
 }
 
-timespec qt_gettime() Q_DECL_NOTHROW
+timespec qt_gettime() noexcept
 {
     timespec tv;
 
@@ -107,13 +107,13 @@ void qt_nanosleep(timespec amount)
     EINTR_LOOP(r, nanosleep(&amount, &amount));
 }
 
-void QElapsedTimer::start() Q_DECL_NOTHROW
+void QElapsedTimer::start() noexcept
 {
     t1 = mach_absolute_time();
     t2 = 0;
 }
 
-qint64 QElapsedTimer::restart() Q_DECL_NOTHROW
+qint64 QElapsedTimer::restart() noexcept
 {
     qint64 old = t1;
     t1 = mach_absolute_time();
@@ -122,39 +122,39 @@ qint64 QElapsedTimer::restart() Q_DECL_NOTHROW
     return absoluteToMSecs(t1 - old);
 }
 
-qint64 QElapsedTimer::nsecsElapsed() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::nsecsElapsed() const noexcept
 {
     uint64_t cpu_time = mach_absolute_time();
     return absoluteToNSecs(cpu_time - t1);
 }
 
-qint64 QElapsedTimer::elapsed() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::elapsed() const noexcept
 {
     uint64_t cpu_time = mach_absolute_time();
     return absoluteToMSecs(cpu_time - t1);
 }
 
-qint64 QElapsedTimer::msecsSinceReference() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::msecsSinceReference() const noexcept
 {
     return absoluteToMSecs(t1);
 }
 
-qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW
+qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const noexcept
 {
     return absoluteToMSecs(other.t1 - t1);
 }
 
-qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW
+qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const noexcept
 {
     return msecsTo(other) / 1000;
 }
 
-bool operator<(const QElapsedTimer &v1, const QElapsedTimer &v2) Q_DECL_NOTHROW
+bool operator<(const QElapsedTimer &v1, const QElapsedTimer &v2) noexcept
 {
     return v1.t1 < v2.t1;
 }
 
-QDeadlineTimer QDeadlineTimer::current(Qt::TimerType timerType) Q_DECL_NOTHROW
+QDeadlineTimer QDeadlineTimer::current(Qt::TimerType timerType) noexcept
 {
     Q_STATIC_ASSERT(!QDeadlineTimerNanosecondsInT2);
     QDeadlineTimer result;
diff --git a/src/corelib/kernel/qelapsedtimer_unix.cpp b/src/corelib/kernel/qelapsedtimer_unix.cpp
index e166d4e3d2..ccc2eeafa3 100644
--- a/src/corelib/kernel/qelapsedtimer_unix.cpp
+++ b/src/corelib/kernel/qelapsedtimer_unix.cpp
@@ -150,12 +150,12 @@ static int unixCheckClockType()
 #endif
 }
 
-bool QElapsedTimer::isMonotonic() Q_DECL_NOTHROW
+bool QElapsedTimer::isMonotonic() noexcept
 {
     return clockType() == MonotonicClock;
 }
 
-QElapsedTimer::ClockType QElapsedTimer::clockType() Q_DECL_NOTHROW
+QElapsedTimer::ClockType QElapsedTimer::clockType() noexcept
 {
     return unixCheckClockType() == CLOCK_REALTIME ? SystemTime : MonotonicClock;
 }
@@ -169,7 +169,7 @@ static inline void do_gettime(qint64 *sec, qint64 *frac)
 }
 
 // used in qcore_unix.cpp and qeventdispatcher_unix.cpp
-struct timespec qt_gettime() Q_DECL_NOTHROW
+struct timespec qt_gettime() noexcept
 {
     qint64 sec, frac;
     do_gettime(&sec, &frac);
@@ -204,17 +204,17 @@ static qint64 elapsedAndRestart(qint64 sec, qint64 frac,
     return (sec * Q_INT64_C(1000000000) + frac) / Q_INT64_C(1000000);
 }
 
-void QElapsedTimer::start() Q_DECL_NOTHROW
+void QElapsedTimer::start() noexcept
 {
     do_gettime(&t1, &t2);
 }
 
-qint64 QElapsedTimer::restart() Q_DECL_NOTHROW
+qint64 QElapsedTimer::restart() noexcept
 {
     return elapsedAndRestart(t1, t2, &t1, &t2);
 }
 
-qint64 QElapsedTimer::nsecsElapsed() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::nsecsElapsed() const noexcept
 {
     qint64 sec, frac;
     do_gettime(&sec, &frac);
@@ -223,34 +223,34 @@ qint64 QElapsedTimer::nsecsElapsed() const Q_DECL_NOTHROW
     return sec * Q_INT64_C(1000000000) + frac;
 }
 
-qint64 QElapsedTimer::elapsed() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::elapsed() const noexcept
 {
     return nsecsElapsed() / Q_INT64_C(1000000);
 }
 
-qint64 QElapsedTimer::msecsSinceReference() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::msecsSinceReference() const noexcept
 {
     return t1 * Q_INT64_C(1000) + t2 / Q_INT64_C(1000000);
 }
 
-qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW
+qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const noexcept
 {
     qint64 secs = other.t1 - t1;
     qint64 fraction = other.t2 - t2;
     return (secs * Q_INT64_C(1000000000) + fraction) / Q_INT64_C(1000000);
 }
 
-qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW
+qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const noexcept
 {
     return other.t1 - t1;
 }
 
-bool operator<(const QElapsedTimer &v1, const QElapsedTimer &v2) Q_DECL_NOTHROW
+bool operator<(const QElapsedTimer &v1, const QElapsedTimer &v2) noexcept
 {
     return v1.t1 < v2.t1 || (v1.t1 == v2.t1 && v1.t2 < v2.t2);
 }
 
-QDeadlineTimer QDeadlineTimer::current(Qt::TimerType timerType) Q_DECL_NOTHROW
+QDeadlineTimer QDeadlineTimer::current(Qt::TimerType timerType) noexcept
 {
     Q_STATIC_ASSERT(QDeadlineTimerNanosecondsInT2);
     QDeadlineTimer result;
diff --git a/src/corelib/kernel/qelapsedtimer_win.cpp b/src/corelib/kernel/qelapsedtimer_win.cpp
index a63290d2f8..d8a50a8277 100644
--- a/src/corelib/kernel/qelapsedtimer_win.cpp
+++ b/src/corelib/kernel/qelapsedtimer_win.cpp
@@ -110,25 +110,25 @@ quint64 qt_msectime()
     return ticksToNanoseconds(getTickCount()) / 1000000;
 }
 
-QElapsedTimer::ClockType QElapsedTimer::clockType() Q_DECL_NOTHROW
+QElapsedTimer::ClockType QElapsedTimer::clockType() noexcept
 {
     resolveCounterFrequency();
 
     return counterFrequency > 0 ? PerformanceCounter : TickCounter;
 }
 
-bool QElapsedTimer::isMonotonic() Q_DECL_NOTHROW
+bool QElapsedTimer::isMonotonic() noexcept
 {
     return true;
 }
 
-void QElapsedTimer::start() Q_DECL_NOTHROW
+void QElapsedTimer::start() noexcept
 {
     t1 = getTickCount();
     t2 = 0;
 }
 
-qint64 QElapsedTimer::restart() Q_DECL_NOTHROW
+qint64 QElapsedTimer::restart() noexcept
 {
     qint64 oldt1 = t1;
     t1 = getTickCount();
@@ -136,40 +136,40 @@ qint64 QElapsedTimer::restart() Q_DECL_NOTHROW
     return ticksToNanoseconds(t1 - oldt1) / 1000000;
 }
 
-qint64 QElapsedTimer::nsecsElapsed() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::nsecsElapsed() const noexcept
 {
     qint64 elapsed = getTickCount() - t1;
     return ticksToNanoseconds(elapsed);
 }
 
-qint64 QElapsedTimer::elapsed() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::elapsed() const noexcept
 {
     qint64 elapsed = getTickCount() - t1;
     return ticksToNanoseconds(elapsed) / 1000000;
 }
 
-qint64 QElapsedTimer::msecsSinceReference() const Q_DECL_NOTHROW
+qint64 QElapsedTimer::msecsSinceReference() const noexcept
 {
     return ticksToNanoseconds(t1) / 1000000;
 }
 
-qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW
+qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const noexcept
 {
     qint64 difference = other.t1 - t1;
     return ticksToNanoseconds(difference) / 1000000;
 }
 
-qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW
+qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const noexcept
 {
     return msecsTo(other) / 1000;
 }
 
-bool operator<(const QElapsedTimer &v1, const QElapsedTimer &v2) Q_DECL_NOTHROW
+bool operator<(const QElapsedTimer &v1, const QElapsedTimer &v2) noexcept
 {
     return (v1.t1 - v2.t1) < 0;
 }
 
-QDeadlineTimer QDeadlineTimer::current(Qt::TimerType timerType) Q_DECL_NOTHROW
+QDeadlineTimer QDeadlineTimer::current(Qt::TimerType timerType) noexcept
 {
     Q_STATIC_ASSERT(!QDeadlineTimerNanosecondsInT2);
     QDeadlineTimer result;
diff --git a/src/corelib/kernel/qeventdispatcher_unix_p.h b/src/corelib/kernel/qeventdispatcher_unix_p.h
index 8cfa4bbdf7..f37edfc967 100644
--- a/src/corelib/kernel/qeventdispatcher_unix_p.h
+++ b/src/corelib/kernel/qeventdispatcher_unix_p.h
@@ -64,10 +64,10 @@ class QEventDispatcherUNIXPrivate;
 
 struct Q_CORE_EXPORT QSocketNotifierSetUNIX final
 {
-    inline QSocketNotifierSetUNIX() Q_DECL_NOTHROW;
+    inline QSocketNotifierSetUNIX() noexcept;
 
-    inline bool isEmpty() const Q_DECL_NOTHROW;
-    inline short events() const Q_DECL_NOTHROW;
+    inline bool isEmpty() const noexcept;
+    inline short events() const noexcept;
 
     QSocketNotifier *notifiers[3];
 };
@@ -150,19 +150,19 @@ public:
     QAtomicInt interrupt; // bool
 };
 
-inline QSocketNotifierSetUNIX::QSocketNotifierSetUNIX() Q_DECL_NOTHROW
+inline QSocketNotifierSetUNIX::QSocketNotifierSetUNIX() noexcept
 {
     notifiers[0] = nullptr;
     notifiers[1] = nullptr;
     notifiers[2] = nullptr;
 }
 
-inline bool QSocketNotifierSetUNIX::isEmpty() const Q_DECL_NOTHROW
+inline bool QSocketNotifierSetUNIX::isEmpty() const noexcept
 {
     return !notifiers[0] && !notifiers[1] && !notifiers[2];
 }
 
-inline short QSocketNotifierSetUNIX::events() const Q_DECL_NOTHROW
+inline short QSocketNotifierSetUNIX::events() const noexcept
 {
     short result = 0;
 
diff --git a/src/corelib/kernel/qfunctions_fake_env_p.h b/src/corelib/kernel/qfunctions_fake_env_p.h
index 7010d2cf5d..68d17ed4a1 100644
--- a/src/corelib/kernel/qfunctions_fake_env_p.h
+++ b/src/corelib/kernel/qfunctions_fake_env_p.h
@@ -72,8 +72,8 @@ Q_DECLARE_TYPEINFO(Variable, Q_MOVABLE_TYPE);
 struct NameEquals {
     typedef bool result_type;
     const char *name;
-    explicit NameEquals(const char *name) Q_DECL_NOTHROW : name(name) {}
-    result_type operator()(const Variable &other) const Q_DECL_NOTHROW
+    explicit NameEquals(const char *name) noexcept : name(name) {}
+    result_type operator()(const Variable &other) const noexcept
     { return qstrcmp(other.name, name) == 0; }
 };
 
diff --git a/src/corelib/kernel/qmetaobject.cpp b/src/corelib/kernel/qmetaobject.cpp
index c15a9f7b0f..ace3eac2ac 100644
--- a/src/corelib/kernel/qmetaobject.cpp
+++ b/src/corelib/kernel/qmetaobject.cpp
@@ -335,7 +335,7 @@ const char *QMetaObject::className() const
 
     \since 5.7
 */
-bool QMetaObject::inherits(const QMetaObject *metaObject) const Q_DECL_NOEXCEPT
+bool QMetaObject::inherits(const QMetaObject *metaObject) const noexcept
 {
     const QMetaObject *m = this;
     do {
diff --git a/src/corelib/kernel/qmetatype.cpp b/src/corelib/kernel/qmetatype.cpp
index 45d0b5df6c..19bda7e8d6 100644
--- a/src/corelib/kernel/qmetatype.cpp
+++ b/src/corelib/kernel/qmetatype.cpp
@@ -915,7 +915,7 @@ template <int... TypeIds> struct MetaTypeOffsets<QtPrivate::IndexesList<TypeIds.
     short offsets[sizeof...(TypeIds)];
     constexpr MetaTypeOffsets() : offsets{calculateOffsetForTypeId(TypeIds)...} {}
 
-    const char *operator[](int typeId) const Q_DECL_NOTHROW
+    const char *operator[](int typeId) const noexcept
     {
         short o = offsets[typeId];
         return o < 0 ? nullptr : metaTypeStrings + o;
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 45e88a2082..0bdf9779b8 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -1427,7 +1427,7 @@ bool QObject::eventFilter(QObject * /* watched */, QEvent * /* event */)
     \sa signalsBlocked(), QSignalBlocker
 */
 
-bool QObject::blockSignals(bool block) Q_DECL_NOTHROW
+bool QObject::blockSignals(bool block) noexcept
 {
     Q_D(QObject);
     bool previous = d->blockSig;
diff --git a/src/corelib/kernel/qobject.h b/src/corelib/kernel/qobject.h
index 63c5a9ad73..6d7b9521c2 100644
--- a/src/corelib/kernel/qobject.h
+++ b/src/corelib/kernel/qobject.h
@@ -142,8 +142,8 @@ public:
     inline bool isWidgetType() const { return d_ptr->isWidget; }
     inline bool isWindowType() const { return d_ptr->isWindow; }
 
-    inline bool signalsBlocked() const Q_DECL_NOTHROW { return d_ptr->blockSig; }
-    bool blockSignals(bool b) Q_DECL_NOTHROW;
+    inline bool signalsBlocked() const noexcept { return d_ptr->blockSig; }
+    bool blockSignals(bool b) noexcept;
 
     QThread *thread() const;
     void moveToThread(QThread *thread);
@@ -436,7 +436,7 @@ protected:
     QScopedPointer<QObjectData> d_ptr;
 
     static const QMetaObject staticQtMetaObject;
-    friend inline const QMetaObject *qt_getQtMetaObject() Q_DECL_NOEXCEPT;
+    friend inline const QMetaObject *qt_getQtMetaObject() noexcept;
 
     friend struct QMetaObject;
     friend struct QMetaObjectPrivate;
@@ -467,7 +467,7 @@ inline QMetaObject::Connection QObject::connect(const QObject *asender, const ch
                                             const char *amember, Qt::ConnectionType atype) const
 { return connect(asender, asignal, this, amember, atype); }
 
-inline const QMetaObject *qt_getQtMetaObject() Q_DECL_NOEXCEPT
+inline const QMetaObject *qt_getQtMetaObject() noexcept
 { return &QObject::staticQtMetaObject; }
 
 #ifndef QT_NO_USERDATA
@@ -540,17 +540,17 @@ Q_CORE_EXPORT QDebug operator<<(QDebug, const QObject *);
 class QSignalBlocker
 {
 public:
-    inline explicit QSignalBlocker(QObject *o) Q_DECL_NOTHROW;
-    inline explicit QSignalBlocker(QObject &o) Q_DECL_NOTHROW;
+    inline explicit QSignalBlocker(QObject *o) noexcept;
+    inline explicit QSignalBlocker(QObject &o) noexcept;
     inline ~QSignalBlocker();
 
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QSignalBlocker(QSignalBlocker &&other) Q_DECL_NOTHROW;
-    inline QSignalBlocker &operator=(QSignalBlocker &&other) Q_DECL_NOTHROW;
+    inline QSignalBlocker(QSignalBlocker &&other) noexcept;
+    inline QSignalBlocker &operator=(QSignalBlocker &&other) noexcept;
 #endif
 
-    inline void reblock() Q_DECL_NOTHROW;
-    inline void unblock() Q_DECL_NOTHROW;
+    inline void reblock() noexcept;
+    inline void unblock() noexcept;
 private:
     Q_DISABLE_COPY(QSignalBlocker)
     QObject * m_o;
@@ -558,20 +558,20 @@ private:
     bool m_inhibited;
 };
 
-QSignalBlocker::QSignalBlocker(QObject *o) Q_DECL_NOTHROW
+QSignalBlocker::QSignalBlocker(QObject *o) noexcept
     : m_o(o),
       m_blocked(o && o->blockSignals(true)),
       m_inhibited(false)
 {}
 
-QSignalBlocker::QSignalBlocker(QObject &o) Q_DECL_NOTHROW
+QSignalBlocker::QSignalBlocker(QObject &o) noexcept
     : m_o(&o),
       m_blocked(o.blockSignals(true)),
       m_inhibited(false)
 {}
 
 #ifdef Q_COMPILER_RVALUE_REFS
-QSignalBlocker::QSignalBlocker(QSignalBlocker &&other) Q_DECL_NOTHROW
+QSignalBlocker::QSignalBlocker(QSignalBlocker &&other) noexcept
     : m_o(other.m_o),
       m_blocked(other.m_blocked),
       m_inhibited(other.m_inhibited)
@@ -579,7 +579,7 @@ QSignalBlocker::QSignalBlocker(QSignalBlocker &&other) Q_DECL_NOTHROW
     other.m_o = nullptr;
 }
 
-QSignalBlocker &QSignalBlocker::operator=(QSignalBlocker &&other) Q_DECL_NOTHROW
+QSignalBlocker &QSignalBlocker::operator=(QSignalBlocker &&other) noexcept
 {
     if (this != &other) {
         // if both *this and other block the same object's signals:
@@ -602,13 +602,13 @@ QSignalBlocker::~QSignalBlocker()
         m_o->blockSignals(m_blocked);
 }
 
-void QSignalBlocker::reblock() Q_DECL_NOTHROW
+void QSignalBlocker::reblock() noexcept
 {
     if (m_o) m_o->blockSignals(true);
     m_inhibited = false;
 }
 
-void QSignalBlocker::unblock() Q_DECL_NOTHROW
+void QSignalBlocker::unblock() noexcept
 {
     if (m_o) m_o->blockSignals(m_blocked);
     m_inhibited = true;
diff --git a/src/corelib/kernel/qobjectdefs.h b/src/corelib/kernel/qobjectdefs.h
index d7ed2b0282..a437a994fd 100644
--- a/src/corelib/kernel/qobjectdefs.h
+++ b/src/corelib/kernel/qobjectdefs.h
@@ -119,13 +119,13 @@ class QString;
 #define Q_ENUMS(x) QT_ANNOTATE_CLASS(qt_enums, x)
 #define Q_FLAGS(x) QT_ANNOTATE_CLASS(qt_enums, x)
 #define Q_ENUM_IMPL(ENUM) \
-    friend Q_DECL_CONSTEXPR const QMetaObject *qt_getEnumMetaObject(ENUM) Q_DECL_NOEXCEPT { return &staticMetaObject; } \
-    friend Q_DECL_CONSTEXPR const char *qt_getEnumName(ENUM) Q_DECL_NOEXCEPT { return #ENUM; }
+    friend Q_DECL_CONSTEXPR const QMetaObject *qt_getEnumMetaObject(ENUM) noexcept { return &staticMetaObject; } \
+    friend Q_DECL_CONSTEXPR const char *qt_getEnumName(ENUM) noexcept { return #ENUM; }
 #define Q_ENUM(x) Q_ENUMS(x) Q_ENUM_IMPL(x)
 #define Q_FLAG(x) Q_FLAGS(x) Q_ENUM_IMPL(x)
 #define Q_ENUM_NS_IMPL(ENUM) \
-    inline Q_DECL_CONSTEXPR const QMetaObject *qt_getEnumMetaObject(ENUM) Q_DECL_NOEXCEPT { return &staticMetaObject; } \
-    inline Q_DECL_CONSTEXPR const char *qt_getEnumName(ENUM) Q_DECL_NOEXCEPT { return #ENUM; }
+    inline Q_DECL_CONSTEXPR const QMetaObject *qt_getEnumMetaObject(ENUM) noexcept { return &staticMetaObject; } \
+    inline Q_DECL_CONSTEXPR const char *qt_getEnumName(ENUM) noexcept { return #ENUM; }
 #define Q_ENUM_NS(x) Q_ENUMS(x) Q_ENUM_NS_IMPL(x)
 #define Q_FLAG_NS(x) Q_FLAGS(x) Q_ENUM_NS_IMPL(x)
 #define Q_SCRIPTABLE QT_ANNOTATE_FUNCTION(qt_scriptable)
@@ -340,7 +340,7 @@ struct Q_CORE_EXPORT QMetaObject
     const char *className() const;
     const QMetaObject *superClass() const;
 
-    bool inherits(const QMetaObject *metaObject) const Q_DECL_NOEXCEPT;
+    bool inherits(const QMetaObject *metaObject) const noexcept;
     QObject *cast(QObject *obj) const;
     const QObject *cast(const QObject *obj) const;
 
@@ -605,8 +605,8 @@ public:
     operator RestrictedBool() const { return d_ptr && isConnected_helper() ? &Connection::d_ptr : nullptr; }
 #endif
 
-    Connection(Connection &&o) Q_DECL_NOTHROW : d_ptr(o.d_ptr) { o.d_ptr = nullptr; }
-    Connection &operator=(Connection &&other) Q_DECL_NOTHROW
+    Connection(Connection &&o) noexcept : d_ptr(o.d_ptr) { o.d_ptr = nullptr; }
+    Connection &operator=(Connection &&other) noexcept
     { qSwap(d_ptr, other.d_ptr); return *this; }
 };
 
diff --git a/src/corelib/kernel/qobjectdefs_impl.h b/src/corelib/kernel/qobjectdefs_impl.h
index aa6bd84e95..31ecc8b20d 100644
--- a/src/corelib/kernel/qobjectdefs_impl.h
+++ b/src/corelib/kernel/qobjectdefs_impl.h
@@ -386,8 +386,8 @@ namespace QtPrivate {
     public:
         explicit QSlotObjectBase(ImplFn fn) : m_ref(1), m_impl(fn) {}
 
-        inline int ref() Q_DECL_NOTHROW { return m_ref.ref(); }
-        inline void destroyIfLastRef() Q_DECL_NOTHROW
+        inline int ref() noexcept { return m_ref.ref(); }
+        inline void destroyIfLastRef() noexcept
         { if (!m_ref.deref()) m_impl(Destroy, this, nullptr, nullptr, nullptr); }
 
         inline bool compare(void **a) { bool ret = false; m_impl(Compare, this, nullptr, a, &ret); return ret; }
diff --git a/src/corelib/kernel/qtimer.h b/src/corelib/kernel/qtimer.h
index 66f317c567..ae5552f1c9 100644
--- a/src/corelib/kernel/qtimer.h
+++ b/src/corelib/kernel/qtimer.h
@@ -218,7 +218,7 @@ private:
     inline int startTimer(int){ return -1;}
     inline void killTimer(int){}
 
-    static Q_DECL_CONSTEXPR Qt::TimerType defaultTypeFor(int msecs) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR Qt::TimerType defaultTypeFor(int msecs) noexcept
     { return msecs >= 2000 ? Qt::CoarseTimer : Qt::PreciseTimer; }
     static void singleShotImpl(int msec, Qt::TimerType timerType,
                                const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj);
diff --git a/src/corelib/kernel/qvariant.h b/src/corelib/kernel/qvariant.h
index 90f5f5fc34..6b35bfa9e9 100644
--- a/src/corelib/kernel/qvariant.h
+++ b/src/corelib/kernel/qvariant.h
@@ -201,7 +201,7 @@ class Q_CORE_EXPORT QVariant
         LastType = 0xffffffff // need this so that gcc >= 3.4 allocates 32 bits for Type
     };
 
-    QVariant() Q_DECL_NOTHROW : d() {}
+    QVariant() noexcept : d() {}
     ~QVariant();
     QVariant(Type type);
     QVariant(int typeId, const void *copy);
@@ -268,13 +268,13 @@ class Q_CORE_EXPORT QVariant
 
     QVariant& operator=(const QVariant &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QVariant(QVariant &&other) Q_DECL_NOTHROW : d(other.d)
+    inline QVariant(QVariant &&other) noexcept : d(other.d)
     { other.d = Private(); }
-    inline QVariant &operator=(QVariant &&other) Q_DECL_NOTHROW
+    inline QVariant &operator=(QVariant &&other) noexcept
     { qSwap(d, other.d); return *this; }
 #endif
 
-    inline void swap(QVariant &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    inline void swap(QVariant &other) noexcept { qSwap(d, other.d); }
 
     Type type() const;
     int userType() const;
@@ -387,15 +387,15 @@ class Q_CORE_EXPORT QVariant
     };
     struct Private
     {
-        inline Private() Q_DECL_NOTHROW : type(Invalid), is_shared(false), is_null(true)
+        inline Private() noexcept : type(Invalid), is_shared(false), is_null(true)
         { data.ptr = nullptr; }
 
         // Internal constructor for initialized variants.
-        explicit inline Private(uint variantType) Q_DECL_NOTHROW
+        explicit inline Private(uint variantType) noexcept
             : type(variantType), is_shared(false), is_null(false)
         {}
 
-        inline Private(const Private &other) Q_DECL_NOTHROW
+        inline Private(const Private &other) noexcept
             : data(other.data), type(other.type),
               is_shared(other.is_shared), is_null(other.is_null)
         {}
diff --git a/src/corelib/mimetypes/qmimeglobpattern_p.h b/src/corelib/mimetypes/qmimeglobpattern_p.h
index bb6f64320b..cf27d6ab30 100644
--- a/src/corelib/mimetypes/qmimeglobpattern_p.h
+++ b/src/corelib/mimetypes/qmimeglobpattern_p.h
@@ -88,7 +88,7 @@ public:
     {
     }
 
-    void swap(QMimeGlobPattern &other) Q_DECL_NOTHROW
+    void swap(QMimeGlobPattern &other) noexcept
     {
         qSwap(m_pattern,         other.m_pattern);
         qSwap(m_mimeType,        other.m_mimeType);
diff --git a/src/corelib/mimetypes/qmimemagicrule_p.h b/src/corelib/mimetypes/qmimemagicrule_p.h
index 6962a6ca59..5091d483b6 100644
--- a/src/corelib/mimetypes/qmimemagicrule_p.h
+++ b/src/corelib/mimetypes/qmimemagicrule_p.h
@@ -69,7 +69,7 @@ public:
     QMimeMagicRule(const QString &typeStr, const QByteArray &value, const QString &offsets,
                    const QByteArray &mask, QString *errorString);
 
-    void swap(QMimeMagicRule &other) Q_DECL_NOTHROW
+    void swap(QMimeMagicRule &other) noexcept
     {
         qSwap(m_type,          other.m_type);
         qSwap(m_value,         other.m_value);
diff --git a/src/corelib/mimetypes/qmimemagicrulematcher_p.h b/src/corelib/mimetypes/qmimemagicrulematcher_p.h
index 5e74e2e3fc..fe714987e6 100644
--- a/src/corelib/mimetypes/qmimemagicrulematcher_p.h
+++ b/src/corelib/mimetypes/qmimemagicrulematcher_p.h
@@ -66,7 +66,7 @@ class QMimeMagicRuleMatcher
 public:
     explicit QMimeMagicRuleMatcher(const QString &mime, unsigned priority = 65535);
 
-    void swap(QMimeMagicRuleMatcher &other) Q_DECL_NOTHROW
+    void swap(QMimeMagicRuleMatcher &other) noexcept
     {
         qSwap(m_list,     other.m_list);
         qSwap(m_priority, other.m_priority);
diff --git a/src/corelib/mimetypes/qmimetype.cpp b/src/corelib/mimetypes/qmimetype.cpp
index 55c7de0c87..cf01c9503b 100644
--- a/src/corelib/mimetypes/qmimetype.cpp
+++ b/src/corelib/mimetypes/qmimetype.cpp
@@ -192,7 +192,7 @@ bool QMimeType::operator==(const QMimeType &other) const
     Returns the hash value for \a key, using
     \a seed to seed the calculation.
  */
-uint qHash(const QMimeType &key, uint seed) Q_DECL_NOTHROW
+uint qHash(const QMimeType &key, uint seed) noexcept
 {
     return qHash(key.d->name, seed);
 }
diff --git a/src/corelib/mimetypes/qmimetype.h b/src/corelib/mimetypes/qmimetype.h
index 8287f1434b..c496af7d58 100644
--- a/src/corelib/mimetypes/qmimetype.h
+++ b/src/corelib/mimetypes/qmimetype.h
@@ -55,7 +55,7 @@ class QMimeTypePrivate;
 class QStringList;
 class QMimeType;
 
-Q_CORE_EXPORT uint qHash(const QMimeType &key, uint seed = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT uint qHash(const QMimeType &key, uint seed = 0) noexcept;
 
 class Q_CORE_EXPORT QMimeType
 {
@@ -79,9 +79,9 @@ public:
     QMimeType(const QMimeType &other);
     QMimeType &operator=(const QMimeType &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QMimeType &operator=(QMimeType &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QMimeType &operator=(QMimeType &&other) noexcept { swap(other); return *this; }
 #endif
-    void swap(QMimeType &other) Q_DECL_NOTHROW
+    void swap(QMimeType &other) noexcept
     {
         qSwap(d, other.d);
     }
@@ -121,7 +121,7 @@ protected:
     friend class QMimeXMLProvider;
     friend class QMimeBinaryProvider;
     friend class QMimeTypePrivate;
-    friend Q_CORE_EXPORT uint qHash(const QMimeType &key, uint seed) Q_DECL_NOTHROW;
+    friend Q_CORE_EXPORT uint qHash(const QMimeType &key, uint seed) noexcept;
 
     QExplicitlySharedDataPointer<QMimeTypePrivate> d;
 };
diff --git a/src/corelib/plugin/quuid.cpp b/src/corelib/plugin/quuid.cpp
index 8bb5e1463a..83873edf6f 100644
--- a/src/corelib/plugin/quuid.cpp
+++ b/src/corelib/plugin/quuid.cpp
@@ -397,7 +397,7 @@ QUuid::QUuid(const QString &text)
 
     \sa toString(), QUuid()
 */
-QUuid QUuid::fromString(QStringView text) Q_DECL_NOTHROW
+QUuid QUuid::fromString(QStringView text) noexcept
 {
     if (text.size() > MaxStringUuidLength)
         text = text.left(MaxStringUuidLength); // text.truncate(MaxStringUuidLength);
@@ -427,7 +427,7 @@ QUuid QUuid::fromString(QStringView text) Q_DECL_NOTHROW
 
     \sa toString(), QUuid()
 */
-QUuid QUuid::fromString(QLatin1String text) Q_DECL_NOTHROW
+QUuid QUuid::fromString(QLatin1String text) noexcept
 {
     if (Q_UNLIKELY(text.size() < MaxStringUuidLength - 2
                    || (text.front() == QLatin1Char('{') && text.size() < MaxStringUuidLength - 1))) {
@@ -864,7 +864,7 @@ QDataStream &operator>>(QDataStream &s, QUuid &id)
     Returns \c true if this is the null UUID
     {00000000-0000-0000-0000-000000000000}; otherwise returns \c false.
 */
-bool QUuid::isNull() const Q_DECL_NOTHROW
+bool QUuid::isNull() const noexcept
 {
     return data4[0] == 0 && data4[1] == 0 && data4[2] == 0 && data4[3] == 0 &&
            data4[4] == 0 && data4[5] == 0 && data4[6] == 0 && data4[7] == 0 &&
@@ -913,7 +913,7 @@ bool QUuid::isNull() const Q_DECL_NOTHROW
 
     \sa version()
 */
-QUuid::Variant QUuid::variant() const Q_DECL_NOTHROW
+QUuid::Variant QUuid::variant() const noexcept
 {
     if (isNull())
         return VarUnknown;
@@ -934,7 +934,7 @@ QUuid::Variant QUuid::variant() const Q_DECL_NOTHROW
 
     \sa variant()
 */
-QUuid::Version QUuid::version() const Q_DECL_NOTHROW
+QUuid::Version QUuid::version() const noexcept
 {
     // Check the 4 MSB of data3
     Version ver = (Version)(data3>>12);
@@ -957,7 +957,7 @@ QUuid::Version QUuid::version() const Q_DECL_NOTHROW
 
     \sa variant()
 */
-bool QUuid::operator<(const QUuid &other) const Q_DECL_NOTHROW
+bool QUuid::operator<(const QUuid &other) const noexcept
 {
     if (variant() != other.variant())
         return variant() < other.variant();
@@ -984,7 +984,7 @@ bool QUuid::operator<(const QUuid &other) const Q_DECL_NOTHROW
 
     \sa variant()
 */
-bool QUuid::operator>(const QUuid &other) const Q_DECL_NOTHROW
+bool QUuid::operator>(const QUuid &other) const noexcept
 {
     return other < *this;
 }
@@ -1089,7 +1089,7 @@ QDebug operator<<(QDebug dbg, const QUuid &id)
     \relates QUuid
     Returns a hash of the UUID \a uuid, using \a seed to seed the calculation.
 */
-uint qHash(const QUuid &uuid, uint seed) Q_DECL_NOTHROW
+uint qHash(const QUuid &uuid, uint seed) noexcept
 {
     return uuid.data1 ^ uuid.data2 ^ (uuid.data3 << 16)
             ^ ((uuid.data4[0] << 24) | (uuid.data4[1] << 16) | (uuid.data4[2] << 8) | uuid.data4[3])
diff --git a/src/corelib/plugin/quuid.h b/src/corelib/plugin/quuid.h
index 08a1843640..713ca070c8 100644
--- a/src/corelib/plugin/quuid.h
+++ b/src/corelib/plugin/quuid.h
@@ -93,13 +93,13 @@ public:
 
 #if defined(Q_COMPILER_UNIFORM_INIT) && !defined(Q_CLANG_QDOC)
 
-    Q_DECL_CONSTEXPR QUuid() Q_DECL_NOTHROW : data1(0), data2(0), data3(0), data4{0,0,0,0,0,0,0,0} {}
+    Q_DECL_CONSTEXPR QUuid() noexcept : data1(0), data2(0), data3(0), data4{0,0,0,0,0,0,0,0} {}
 
     Q_DECL_CONSTEXPR QUuid(uint l, ushort w1, ushort w2, uchar b1, uchar b2, uchar b3,
-                           uchar b4, uchar b5, uchar b6, uchar b7, uchar b8) Q_DECL_NOTHROW
+                           uchar b4, uchar b5, uchar b6, uchar b7, uchar b8) noexcept
         : data1(l), data2(w1), data3(w2), data4{b1, b2, b3, b4, b5, b6, b7, b8} {}
 #else
-    QUuid() Q_DECL_NOTHROW
+    QUuid() noexcept
     {
         data1 = 0;
         data2 = 0;
@@ -107,7 +107,7 @@ public:
         for(int i = 0; i < 8; i++)
             data4[i] = 0;
     }
-    QUuid(uint l, ushort w1, ushort w2, uchar b1, uchar b2, uchar b3, uchar b4, uchar b5, uchar b6, uchar b7, uchar b8) Q_DECL_NOTHROW
+    QUuid(uint l, ushort w1, ushort w2, uchar b1, uchar b2, uchar b3, uchar b4, uchar b5, uchar b6, uchar b7, uchar b8) noexcept
     {
         data1 = l;
         data2 = w1;
@@ -124,8 +124,8 @@ public:
 #endif
 
     QUuid(const QString &);
-    static QUuid fromString(QStringView string) Q_DECL_NOTHROW;
-    static QUuid fromString(QLatin1String string) Q_DECL_NOTHROW;
+    static QUuid fromString(QStringView string) noexcept;
+    static QUuid fromString(QLatin1String string) noexcept;
     QUuid(const char *);
     QString toString() const;
     QString toString(StringFormat mode) const; // ### Qt6: merge with previous
@@ -134,9 +134,9 @@ public:
     QByteArray toByteArray(StringFormat mode) const; // ### Qt6: merge with previous
     QByteArray toRfc4122() const;
     static QUuid fromRfc4122(const QByteArray &);
-    bool isNull() const Q_DECL_NOTHROW;
+    bool isNull() const noexcept;
 
-    Q_DECL_RELAXED_CONSTEXPR bool operator==(const QUuid &orig) const Q_DECL_NOTHROW
+    Q_DECL_RELAXED_CONSTEXPR bool operator==(const QUuid &orig) const noexcept
     {
         if (data1 != orig.data1 || data2 != orig.data2 ||
              data3 != orig.data3)
@@ -149,24 +149,24 @@ public:
         return true;
     }
 
-    Q_DECL_RELAXED_CONSTEXPR bool operator!=(const QUuid &orig) const Q_DECL_NOTHROW
+    Q_DECL_RELAXED_CONSTEXPR bool operator!=(const QUuid &orig) const noexcept
     {
         return !(*this == orig);
     }
 
-    bool operator<(const QUuid &other) const Q_DECL_NOTHROW;
-    bool operator>(const QUuid &other) const Q_DECL_NOTHROW;
+    bool operator<(const QUuid &other) const noexcept;
+    bool operator>(const QUuid &other) const noexcept;
 
 #if defined(Q_OS_WIN) || defined(Q_CLANG_QDOC)
     // On Windows we have a type GUID that is used by the platform API, so we
     // provide convenience operators to cast from and to this type.
 #if defined(Q_COMPILER_UNIFORM_INIT) && !defined(Q_CLANG_QDOC)
-    Q_DECL_CONSTEXPR QUuid(const GUID &guid) Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR QUuid(const GUID &guid) noexcept
         : data1(guid.Data1), data2(guid.Data2), data3(guid.Data3),
           data4{guid.Data4[0], guid.Data4[1], guid.Data4[2], guid.Data4[3],
                 guid.Data4[4], guid.Data4[5], guid.Data4[6], guid.Data4[7]} {}
 #else
-    QUuid(const GUID &guid) Q_DECL_NOTHROW
+    QUuid(const GUID &guid) noexcept
     {
         data1 = guid.Data1;
         data2 = guid.Data2;
@@ -176,24 +176,24 @@ public:
     }
 #endif
 
-    Q_DECL_RELAXED_CONSTEXPR QUuid &operator=(const GUID &guid) Q_DECL_NOTHROW
+    Q_DECL_RELAXED_CONSTEXPR QUuid &operator=(const GUID &guid) noexcept
     {
         *this = QUuid(guid);
         return *this;
     }
 
-    Q_DECL_RELAXED_CONSTEXPR operator GUID() const Q_DECL_NOTHROW
+    Q_DECL_RELAXED_CONSTEXPR operator GUID() const noexcept
     {
         GUID guid = { data1, data2, data3, { data4[0], data4[1], data4[2], data4[3], data4[4], data4[5], data4[6], data4[7] } };
         return guid;
     }
 
-    Q_DECL_RELAXED_CONSTEXPR bool operator==(const GUID &guid) const Q_DECL_NOTHROW
+    Q_DECL_RELAXED_CONSTEXPR bool operator==(const GUID &guid) const noexcept
     {
         return *this == QUuid(guid);
     }
 
-    Q_DECL_RELAXED_CONSTEXPR bool operator!=(const GUID &guid) const Q_DECL_NOTHROW
+    Q_DECL_RELAXED_CONSTEXPR bool operator!=(const GUID &guid) const noexcept
     {
         return !(*this == guid);
     }
@@ -216,8 +216,8 @@ public:
     }
 
 
-    QUuid::Variant variant() const Q_DECL_NOTHROW;
-    QUuid::Version version() const Q_DECL_NOTHROW;
+    QUuid::Variant variant() const noexcept;
+    QUuid::Version version() const noexcept;
 
 #if defined(Q_OS_DARWIN) || defined(Q_CLANG_QDOC)
     static QUuid fromCFUUID(CFUUIDRef uuid);
@@ -243,11 +243,11 @@ Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QUuid &);
 Q_CORE_EXPORT QDebug operator<<(QDebug, const QUuid &);
 #endif
 
-Q_CORE_EXPORT uint qHash(const QUuid &uuid, uint seed = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT uint qHash(const QUuid &uuid, uint seed = 0) noexcept;
 
-inline bool operator<=(const QUuid &lhs, const QUuid &rhs) Q_DECL_NOTHROW
+inline bool operator<=(const QUuid &lhs, const QUuid &rhs) noexcept
 { return !(rhs < lhs); }
-inline bool operator>=(const QUuid &lhs, const QUuid &rhs) Q_DECL_NOTHROW
+inline bool operator>=(const QUuid &lhs, const QUuid &rhs) noexcept
 { return !(lhs < rhs); }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/serialization/qjson_p.h b/src/corelib/serialization/qjson_p.h
index a9e7059cbe..85fb2a1254 100644
--- a/src/corelib/serialization/qjson_p.h
+++ b/src/corelib/serialization/qjson_p.h
@@ -304,7 +304,7 @@ public:
         return *this;
     }
 
-    QLatin1String toQLatin1String() const Q_DECL_NOTHROW {
+    QLatin1String toQLatin1String() const noexcept {
         return QLatin1String(d->latin1, d->length);
     }
 
@@ -339,23 +339,23 @@ public:
 };
 
 #define DEF_OP(op) \
-    inline bool operator op(Latin1String lhs, Latin1String rhs) Q_DECL_NOTHROW \
+    inline bool operator op(Latin1String lhs, Latin1String rhs) noexcept \
     { \
         return lhs.toQLatin1String() op rhs.toQLatin1String(); \
     } \
-    inline bool operator op(QLatin1String lhs, Latin1String rhs) Q_DECL_NOTHROW \
+    inline bool operator op(QLatin1String lhs, Latin1String rhs) noexcept \
     { \
         return lhs op rhs.toQLatin1String(); \
     } \
-    inline bool operator op(Latin1String lhs, QLatin1String rhs) Q_DECL_NOTHROW \
+    inline bool operator op(Latin1String lhs, QLatin1String rhs) noexcept \
     { \
         return lhs.toQLatin1String() op rhs; \
     } \
-    inline bool operator op(const QString &lhs, Latin1String rhs) Q_DECL_NOTHROW \
+    inline bool operator op(const QString &lhs, Latin1String rhs) noexcept \
     { \
         return lhs op rhs.toQLatin1String(); \
     } \
-    inline bool operator op(Latin1String lhs, const QString &rhs) Q_DECL_NOTHROW \
+    inline bool operator op(Latin1String lhs, const QString &rhs) noexcept \
     { \
         return lhs.toQLatin1String() op rhs; \
     } \
diff --git a/src/corelib/serialization/qjsonarray.h b/src/corelib/serialization/qjsonarray.h
index ba346fb848..86b7bf9d76 100644
--- a/src/corelib/serialization/qjsonarray.h
+++ b/src/corelib/serialization/qjsonarray.h
@@ -72,7 +72,7 @@ public:
     QJsonArray(const QJsonArray &other);
     QJsonArray &operator =(const QJsonArray &other);
 
-    QJsonArray(QJsonArray &&other) Q_DECL_NOTHROW
+    QJsonArray(QJsonArray &&other) noexcept
         : d(other.d),
           a(other.a)
     {
@@ -80,7 +80,7 @@ public:
         other.a = nullptr;
     }
 
-    QJsonArray &operator =(QJsonArray &&other) Q_DECL_NOTHROW
+    QJsonArray &operator =(QJsonArray &&other) noexcept
     {
         swap(other);
         return *this;
@@ -115,7 +115,7 @@ public:
     bool operator==(const QJsonArray &other) const;
     bool operator!=(const QJsonArray &other) const;
 
-    void swap(QJsonArray &other) Q_DECL_NOTHROW
+    void swap(QJsonArray &other) noexcept
     {
         qSwap(d, other.d);
         qSwap(a, other.a);
diff --git a/src/corelib/serialization/qjsondocument.h b/src/corelib/serialization/qjsondocument.h
index a749439b7d..a8006a6cc5 100644
--- a/src/corelib/serialization/qjsondocument.h
+++ b/src/corelib/serialization/qjsondocument.h
@@ -93,19 +93,19 @@ public:
     QJsonDocument(const QJsonDocument &other);
     QJsonDocument &operator =(const QJsonDocument &other);
 
-    QJsonDocument(QJsonDocument &&other) Q_DECL_NOTHROW
+    QJsonDocument(QJsonDocument &&other) noexcept
         : d(other.d)
     {
         other.d = nullptr;
     }
 
-    QJsonDocument &operator =(QJsonDocument &&other) Q_DECL_NOTHROW
+    QJsonDocument &operator =(QJsonDocument &&other) noexcept
     {
         swap(other);
         return *this;
     }
 
-    void swap(QJsonDocument &other) Q_DECL_NOTHROW
+    void swap(QJsonDocument &other) noexcept
     {
         qSwap(d, other.d);
     }
diff --git a/src/corelib/serialization/qjsonobject.h b/src/corelib/serialization/qjsonobject.h
index 80fe6b2f3f..92d45cc838 100644
--- a/src/corelib/serialization/qjsonobject.h
+++ b/src/corelib/serialization/qjsonobject.h
@@ -74,20 +74,20 @@ public:
     QJsonObject(const QJsonObject &other);
     QJsonObject &operator =(const QJsonObject &other);
 
-    QJsonObject(QJsonObject &&other) Q_DECL_NOTHROW
+    QJsonObject(QJsonObject &&other) noexcept
         : d(other.d), o(other.o)
     {
         other.d = nullptr;
         other.o = nullptr;
     }
 
-    QJsonObject &operator =(QJsonObject &&other) Q_DECL_NOTHROW
+    QJsonObject &operator =(QJsonObject &&other) noexcept
     {
         swap(other);
         return *this;
     }
 
-    void swap(QJsonObject &other) Q_DECL_NOTHROW
+    void swap(QJsonObject &other) noexcept
     {
         qSwap(d, other.d);
         qSwap(o, other.o);
diff --git a/src/corelib/serialization/qjsonvalue.h b/src/corelib/serialization/qjsonvalue.h
index 0339eb59f7..37d84f9e60 100644
--- a/src/corelib/serialization/qjsonvalue.h
+++ b/src/corelib/serialization/qjsonvalue.h
@@ -92,7 +92,7 @@ public:
     QJsonValue(const QJsonValue &other);
     QJsonValue &operator =(const QJsonValue &other);
 
-    QJsonValue(QJsonValue &&other) Q_DECL_NOTHROW
+    QJsonValue(QJsonValue &&other) noexcept
         : ui(other.ui),
           d(other.d),
           t(other.t)
@@ -102,13 +102,13 @@ public:
         other.t = Null;
     }
 
-    QJsonValue &operator =(QJsonValue &&other) Q_DECL_NOTHROW
+    QJsonValue &operator =(QJsonValue &&other) noexcept
     {
         swap(other);
         return *this;
     }
 
-    void swap(QJsonValue &other) Q_DECL_NOTHROW
+    void swap(QJsonValue &other) noexcept
     {
         qSwap(ui, other.ui);
         qSwap(d, other.d);
diff --git a/src/corelib/serialization/qtextstream.h b/src/corelib/serialization/qtextstream.h
index 7673e5d87e..4efa84f1f1 100644
--- a/src/corelib/serialization/qtextstream.h
+++ b/src/corelib/serialization/qtextstream.h
@@ -213,8 +213,8 @@ typedef void (QTextStream::*QTSMFC)(QChar); // manipulator w/QChar argument
 class Q_CORE_EXPORT QTextStreamManipulator
 {
 public:
-    Q_DECL_CONSTEXPR QTextStreamManipulator(QTSMFI m, int a) Q_DECL_NOTHROW : mf(m), mc(nullptr), arg(a), ch() {}
-    Q_DECL_CONSTEXPR QTextStreamManipulator(QTSMFC m, QChar c) Q_DECL_NOTHROW : mf(nullptr), mc(m), arg(-1), ch(c) {}
+    Q_DECL_CONSTEXPR QTextStreamManipulator(QTSMFI m, int a) noexcept : mf(m), mc(nullptr), arg(a), ch() {}
+    Q_DECL_CONSTEXPR QTextStreamManipulator(QTSMFC m, QChar c) noexcept : mf(nullptr), mc(m), arg(-1), ch(c) {}
     void exec(QTextStream &s) { if (mf) { (s.*mf)(arg); } else { (s.*mc)(ch); } }
 
 private:
diff --git a/src/corelib/serialization/qxmlstream.h b/src/corelib/serialization/qxmlstream.h
index d30c6bc01f..fedd149fd0 100644
--- a/src/corelib/serialization/qxmlstream.h
+++ b/src/corelib/serialization/qxmlstream.h
@@ -60,16 +60,16 @@ public:
         :m_string(aString.string()?*aString.string():QString()), m_position(aString.position()), m_size(aString.size()){}
     QXmlStreamStringRef(const QString &aString) : m_string(aString), m_position(0), m_size(m_string.size()) {}
 #ifdef Q_COMPILER_RVALUE_REFS
-    QXmlStreamStringRef(QString &&aString) Q_DECL_NOTHROW : m_string(std::move(aString)), m_position(0), m_size(m_string.size()) {}
+    QXmlStreamStringRef(QString &&aString) noexcept : m_string(std::move(aString)), m_position(0), m_size(m_string.size()) {}
 #endif
 
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
     QXmlStreamStringRef(const QXmlStreamStringRef &other) // = default
         : m_string(other.m_string), m_position(other.m_position), m_size(other.m_size) {}
 #ifdef Q_COMPILER_RVALUE_REFS
-    QXmlStreamStringRef(QXmlStreamStringRef &&other) Q_DECL_NOTHROW // = default
+    QXmlStreamStringRef(QXmlStreamStringRef &&other) noexcept // = default
         : m_string(std::move(other.m_string)), m_position(other.m_position), m_size(other.m_size) {}
-    QXmlStreamStringRef &operator=(QXmlStreamStringRef &&other) Q_DECL_NOTHROW // = default
+    QXmlStreamStringRef &operator=(QXmlStreamStringRef &&other) noexcept // = default
     { swap(other); return *this; }
 #endif
     QXmlStreamStringRef &operator=(const QXmlStreamStringRef &other) // = default
@@ -79,7 +79,7 @@ public:
                                      // ### Qt 5, since that would change the way its passed to functions. In Qt 6, remove all.
 #endif // Qt < 6.0
 
-    void swap(QXmlStreamStringRef &other) Q_DECL_NOTHROW
+    void swap(QXmlStreamStringRef &other) noexcept
     {
         qSwap(m_string, other.m_string);
         qSwap(m_position, other.m_position);
@@ -112,7 +112,7 @@ public:
     QXmlStreamAttribute(const QString &namespaceUri, const QString &name, const QString &value);
     QXmlStreamAttribute(const QXmlStreamAttribute &);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QXmlStreamAttribute(QXmlStreamAttribute &&other) Q_DECL_NOTHROW // = default;
+    QXmlStreamAttribute(QXmlStreamAttribute &&other) noexcept // = default;
         : m_name(std::move(other.m_name)),
           m_namespaceUri(std::move(other.m_namespaceUri)),
           m_qualifiedName(std::move(other.m_qualifiedName)),
@@ -122,7 +122,7 @@ public:
     {
         other.reserved = nullptr;
     }
-    QXmlStreamAttribute &operator=(QXmlStreamAttribute &&other) Q_DECL_NOTHROW // = default;
+    QXmlStreamAttribute &operator=(QXmlStreamAttribute &&other) noexcept // = default;
     {
         m_name = std::move(other.m_name);
         m_namespaceUri = std::move(other.m_namespaceUri);
@@ -199,14 +199,14 @@ public:
     QXmlStreamNamespaceDeclaration();
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     QXmlStreamNamespaceDeclaration(const QXmlStreamNamespaceDeclaration &);
-    QXmlStreamNamespaceDeclaration(QXmlStreamNamespaceDeclaration &&other) Q_DECL_NOTHROW // = default
+    QXmlStreamNamespaceDeclaration(QXmlStreamNamespaceDeclaration &&other) noexcept // = default
         : m_prefix(std::move(other.m_prefix)),
           m_namespaceUri(std::move(other.m_namespaceUri)),
           reserved(other.reserved)
     {
         other.reserved = nullptr;
     }
-    QXmlStreamNamespaceDeclaration &operator=(QXmlStreamNamespaceDeclaration &&other) Q_DECL_NOTHROW // = default
+    QXmlStreamNamespaceDeclaration &operator=(QXmlStreamNamespaceDeclaration &&other) noexcept // = default
     {
         m_prefix = std::move(other.m_prefix);
         m_namespaceUri = std::move(other.m_namespaceUri);
@@ -242,7 +242,7 @@ public:
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     ~QXmlStreamNotationDeclaration();
     QXmlStreamNotationDeclaration(const QXmlStreamNotationDeclaration &);
-    QXmlStreamNotationDeclaration(QXmlStreamNotationDeclaration &&other) Q_DECL_NOTHROW // = default
+    QXmlStreamNotationDeclaration(QXmlStreamNotationDeclaration &&other) noexcept // = default
         : m_name(std::move(other.m_name)),
           m_systemId(std::move(other.m_systemId)),
           m_publicId(std::move(other.m_publicId)),
@@ -251,7 +251,7 @@ public:
         other.reserved = nullptr;
     }
     QXmlStreamNotationDeclaration& operator=(const QXmlStreamNotationDeclaration &);
-    QXmlStreamNotationDeclaration &operator=(QXmlStreamNotationDeclaration &&other) Q_DECL_NOTHROW // = default
+    QXmlStreamNotationDeclaration &operator=(QXmlStreamNotationDeclaration &&other) noexcept // = default
     {
         m_name = std::move(other.m_name);
         m_systemId = std::move(other.m_systemId);
@@ -287,7 +287,7 @@ public:
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     ~QXmlStreamEntityDeclaration();
     QXmlStreamEntityDeclaration(const QXmlStreamEntityDeclaration &);
-    QXmlStreamEntityDeclaration(QXmlStreamEntityDeclaration &&other) Q_DECL_NOTHROW // = default
+    QXmlStreamEntityDeclaration(QXmlStreamEntityDeclaration &&other) noexcept // = default
         : m_name(std::move(other.m_name)),
           m_notationName(std::move(other.m_notationName)),
           m_systemId(std::move(other.m_systemId)),
@@ -298,7 +298,7 @@ public:
         other.reserved = nullptr;
     }
     QXmlStreamEntityDeclaration& operator=(const QXmlStreamEntityDeclaration &);
-    QXmlStreamEntityDeclaration &operator=(QXmlStreamEntityDeclaration &&other) Q_DECL_NOTHROW // = default
+    QXmlStreamEntityDeclaration &operator=(QXmlStreamEntityDeclaration &&other) noexcept // = default
     {
         m_name = std::move(other.m_name);
         m_notationName = std::move(other.m_notationName);
diff --git a/src/corelib/statemachine/qstatemachine_p.h b/src/corelib/statemachine/qstatemachine_p.h
index c66130b8ce..3d12477c87 100644
--- a/src/corelib/statemachine/qstatemachine_p.h
+++ b/src/corelib/statemachine/qstatemachine_p.h
@@ -222,14 +222,14 @@ public:
         { return qHash(qMakePair(key.obj, key.prop), seed); }
         friend uint qHash(const RestorableId &key) Q_DECL_NOEXCEPT_EXPR(noexcept(qHash(key, 0U)))
         { return qHash(key, 0U); }
-        friend bool operator==(const RestorableId &lhs, const RestorableId &rhs) Q_DECL_NOTHROW
+        friend bool operator==(const RestorableId &lhs, const RestorableId &rhs) noexcept
         { return lhs.obj == rhs.obj && lhs.prop == rhs.prop; }
-        friend bool operator!=(const RestorableId &lhs, const RestorableId &rhs) Q_DECL_NOTHROW
+        friend bool operator!=(const RestorableId &lhs, const RestorableId &rhs) noexcept
         { return !operator==(lhs, rhs); }
     public:
-        explicit RestorableId(QObject *o, QByteArray p) Q_DECL_NOTHROW : guard(o), obj(o), prop(qMove(p)) {}
-        QObject *object() const Q_DECL_NOTHROW { return guard; }
-        QByteArray propertyName() const Q_DECL_NOTHROW { return prop; }
+        explicit RestorableId(QObject *o, QByteArray p) noexcept : guard(o), obj(o), prop(qMove(p)) {}
+        QObject *object() const noexcept { return guard; }
+        QByteArray propertyName() const noexcept { return prop; }
     };
     QHash<QAbstractState*, QHash<RestorableId, QVariant> > registeredRestorablesForState;
     bool hasRestorable(QAbstractState *state, QObject *object, const QByteArray &propertyName) const;
@@ -271,7 +271,7 @@ public:
         QList<QAbstractAnimation*> handledAnimations;
         QList<QAbstractAnimation*> localResetEndValues;
 
-        void swap(InitializeAnimationResult &other) Q_DECL_NOTHROW
+        void swap(InitializeAnimationResult &other) noexcept
         {
             qSwap(handledAnimations,   other.handledAnimations);
             qSwap(localResetEndValues, other.localResetEndValues);
diff --git a/src/corelib/thread/qatomic.h b/src/corelib/thread/qatomic.h
index f842534c38..280ce96b76 100644
--- a/src/corelib/thread/qatomic.h
+++ b/src/corelib/thread/qatomic.h
@@ -57,15 +57,15 @@ class QAtomicInteger : public QBasicAtomicInteger<T>
 public:
     // Non-atomic API
 #ifdef QT_BASIC_ATOMIC_HAS_CONSTRUCTORS
-    constexpr QAtomicInteger(T value = 0) Q_DECL_NOTHROW : QBasicAtomicInteger<T>(value) {}
+    constexpr QAtomicInteger(T value = 0) noexcept : QBasicAtomicInteger<T>(value) {}
 #else
-    inline QAtomicInteger(T value = 0) Q_DECL_NOTHROW
+    inline QAtomicInteger(T value = 0) noexcept
     {
         this->_q_value = value;
     }
 #endif
 
-    inline QAtomicInteger(const QAtomicInteger &other) Q_DECL_NOTHROW
+    inline QAtomicInteger(const QAtomicInteger &other) noexcept
 #ifdef QT_BASIC_ATOMIC_HAS_CONSTRUCTORS
         : QBasicAtomicInteger<T>()
 #endif
@@ -73,7 +73,7 @@ public:
         this->storeRelease(other.loadAcquire());
     }
 
-    inline QAtomicInteger &operator=(const QAtomicInteger &other) Q_DECL_NOTHROW
+    inline QAtomicInteger &operator=(const QAtomicInteger &other) noexcept
     {
         this->storeRelease(other.loadAcquire());
         return *this;
@@ -159,7 +159,7 @@ public:
 #ifdef QT_BASIC_ATOMIC_HAS_CONSTRUCTORS
     constexpr
 #endif
-    QAtomicInt(int value = 0) Q_DECL_NOTHROW : QAtomicInteger<int>(value) {}
+    QAtomicInt(int value = 0) noexcept : QAtomicInteger<int>(value) {}
 };
 
 // High-level atomic pointer operations
@@ -168,14 +168,14 @@ class QAtomicPointer : public QBasicAtomicPointer<T>
 {
 public:
 #ifdef QT_BASIC_ATOMIC_HAS_CONSTRUCTORS
-    constexpr QAtomicPointer(T *value = nullptr) Q_DECL_NOTHROW : QBasicAtomicPointer<T>(value) {}
+    constexpr QAtomicPointer(T *value = nullptr) noexcept : QBasicAtomicPointer<T>(value) {}
 #else
-    inline QAtomicPointer(T *value = nullptr) Q_DECL_NOTHROW
+    inline QAtomicPointer(T *value = nullptr) noexcept
     {
         this->store(value);
     }
 #endif
-    inline QAtomicPointer(const QAtomicPointer<T> &other) Q_DECL_NOTHROW
+    inline QAtomicPointer(const QAtomicPointer<T> &other) noexcept
 #ifdef QT_BASIC_ATOMIC_HAS_CONSTRUCTORS
         : QBasicAtomicPointer<T>()
 #endif
@@ -183,7 +183,7 @@ public:
         this->storeRelease(other.loadAcquire());
     }
 
-    inline QAtomicPointer<T> &operator=(const QAtomicPointer<T> &other) Q_DECL_NOTHROW
+    inline QAtomicPointer<T> &operator=(const QAtomicPointer<T> &other) noexcept
     {
         this->storeRelease(other.loadAcquire());
         return *this;
diff --git a/src/corelib/thread/qatomic_bootstrap.h b/src/corelib/thread/qatomic_bootstrap.h
index 27a67fb2ee..c4279ee7b1 100644
--- a/src/corelib/thread/qatomic_bootstrap.h
+++ b/src/corelib/thread/qatomic_bootstrap.h
@@ -56,16 +56,16 @@ template <typename T> struct QAtomicOps: QGenericAtomicOps<QAtomicOps<T> >
 {
     typedef T Type;
 
-    static bool ref(T &_q_value) Q_DECL_NOTHROW
+    static bool ref(T &_q_value) noexcept
     {
         return ++_q_value != 0;
     }
-    static bool deref(T &_q_value) Q_DECL_NOTHROW
+    static bool deref(T &_q_value) noexcept
     {
         return --_q_value != 0;
     }
 
-    static bool testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) Q_DECL_NOTHROW
+    static bool testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) noexcept
     {
         if (currentValue)
             *currentValue = _q_value;
@@ -76,7 +76,7 @@ template <typename T> struct QAtomicOps: QGenericAtomicOps<QAtomicOps<T> >
         return false;
     }
 
-    static T fetchAndStoreRelaxed(T &_q_value, T newValue) Q_DECL_NOTHROW
+    static T fetchAndStoreRelaxed(T &_q_value, T newValue) noexcept
     {
         T tmp = _q_value;
         _q_value = newValue;
@@ -84,7 +84,7 @@ template <typename T> struct QAtomicOps: QGenericAtomicOps<QAtomicOps<T> >
     }
 
     template <typename AdditiveType> static
-    T fetchAndAddRelaxed(T &_q_value, AdditiveType valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddRelaxed(T &_q_value, AdditiveType valueToAdd) noexcept
     {
         T returnValue = _q_value;
         _q_value += valueToAdd;
diff --git a/src/corelib/thread/qatomic_cxx11.h b/src/corelib/thread/qatomic_cxx11.h
index 2fc0bf5419..32d27734fc 100644
--- a/src/corelib/thread/qatomic_cxx11.h
+++ b/src/corelib/thread/qatomic_cxx11.h
@@ -222,43 +222,43 @@ template <typename X> struct QAtomicOps
     typedef std::atomic<X> Type;
 
     template <typename T> static inline
-    T load(const std::atomic<T> &_q_value) Q_DECL_NOTHROW
+    T load(const std::atomic<T> &_q_value) noexcept
     {
         return _q_value.load(std::memory_order_relaxed);
     }
 
     template <typename T> static inline
-    T load(const volatile std::atomic<T> &_q_value) Q_DECL_NOTHROW
+    T load(const volatile std::atomic<T> &_q_value) noexcept
     {
         return _q_value.load(std::memory_order_relaxed);
     }
 
     template <typename T> static inline
-    T loadAcquire(const std::atomic<T> &_q_value) Q_DECL_NOTHROW
+    T loadAcquire(const std::atomic<T> &_q_value) noexcept
     {
         return _q_value.load(std::memory_order_acquire);
     }
 
     template <typename T> static inline
-    T loadAcquire(const volatile std::atomic<T> &_q_value) Q_DECL_NOTHROW
+    T loadAcquire(const volatile std::atomic<T> &_q_value) noexcept
     {
         return _q_value.load(std::memory_order_acquire);
     }
 
     template <typename T> static inline
-    void store(std::atomic<T> &_q_value, T newValue) Q_DECL_NOTHROW
+    void store(std::atomic<T> &_q_value, T newValue) noexcept
     {
         _q_value.store(newValue, std::memory_order_relaxed);
     }
 
     template <typename T> static inline
-    void storeRelease(std::atomic<T> &_q_value, T newValue) Q_DECL_NOTHROW
+    void storeRelease(std::atomic<T> &_q_value, T newValue) noexcept
     {
         _q_value.store(newValue, std::memory_order_release);
     }
 
-    static inline Q_DECL_CONSTEXPR bool isReferenceCountingNative() Q_DECL_NOTHROW { return isTestAndSetNative(); }
-    static inline Q_DECL_CONSTEXPR bool isReferenceCountingWaitFree() Q_DECL_NOTHROW { return false; }
+    static inline Q_DECL_CONSTEXPR bool isReferenceCountingNative() noexcept { return isTestAndSetNative(); }
+    static inline Q_DECL_CONSTEXPR bool isReferenceCountingWaitFree() noexcept { return false; }
     template <typename T>
     static inline bool ref(std::atomic<T> &_q_value)
     {
@@ -266,17 +266,17 @@ template <typename X> struct QAtomicOps
     }
 
     template <typename T>
-    static inline bool deref(std::atomic<T> &_q_value) Q_DECL_NOTHROW
+    static inline bool deref(std::atomic<T> &_q_value) noexcept
     {
         return --_q_value != 0;
     }
 
-    static inline Q_DECL_CONSTEXPR bool isTestAndSetNative() Q_DECL_NOTHROW
+    static inline Q_DECL_CONSTEXPR bool isTestAndSetNative() noexcept
     { return QAtomicTraits<sizeof(X)>::isLockFree(); }
-    static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() Q_DECL_NOTHROW { return false; }
+    static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() noexcept { return false; }
 
     template <typename T>
-    static bool testAndSetRelaxed(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) Q_DECL_NOTHROW
+    static bool testAndSetRelaxed(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) noexcept
     {
         bool tmp = _q_value.compare_exchange_strong(expectedValue, newValue, std::memory_order_relaxed, std::memory_order_relaxed);
         if (currentValue)
@@ -285,7 +285,7 @@ template <typename X> struct QAtomicOps
     }
 
     template <typename T>
-    static bool testAndSetAcquire(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) Q_DECL_NOTHROW
+    static bool testAndSetAcquire(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) noexcept
     {
         bool tmp = _q_value.compare_exchange_strong(expectedValue, newValue, std::memory_order_acquire, std::memory_order_acquire);
         if (currentValue)
@@ -294,7 +294,7 @@ template <typename X> struct QAtomicOps
     }
 
     template <typename T>
-    static bool testAndSetRelease(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) Q_DECL_NOTHROW
+    static bool testAndSetRelease(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) noexcept
     {
         bool tmp = _q_value.compare_exchange_strong(expectedValue, newValue, std::memory_order_release, std::memory_order_relaxed);
         if (currentValue)
@@ -303,7 +303,7 @@ template <typename X> struct QAtomicOps
     }
 
     template <typename T>
-    static bool testAndSetOrdered(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) Q_DECL_NOTHROW
+    static bool testAndSetOrdered(std::atomic<T> &_q_value, T expectedValue, T newValue, T *currentValue = nullptr) noexcept
     {
         bool tmp = _q_value.compare_exchange_strong(expectedValue, newValue, std::memory_order_acq_rel, std::memory_order_acquire);
         if (currentValue)
@@ -311,152 +311,152 @@ template <typename X> struct QAtomicOps
         return tmp;
     }
 
-    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreNative() Q_DECL_NOTHROW { return isTestAndSetNative(); }
-    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() Q_DECL_NOTHROW { return false; }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreNative() noexcept { return isTestAndSetNative(); }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() noexcept { return false; }
 
     template <typename T>
-    static T fetchAndStoreRelaxed(std::atomic<T> &_q_value, T newValue) Q_DECL_NOTHROW
+    static T fetchAndStoreRelaxed(std::atomic<T> &_q_value, T newValue) noexcept
     {
         return _q_value.exchange(newValue, std::memory_order_relaxed);
     }
 
     template <typename T>
-    static T fetchAndStoreAcquire(std::atomic<T> &_q_value, T newValue) Q_DECL_NOTHROW
+    static T fetchAndStoreAcquire(std::atomic<T> &_q_value, T newValue) noexcept
     {
         return _q_value.exchange(newValue, std::memory_order_acquire);
     }
 
     template <typename T>
-    static T fetchAndStoreRelease(std::atomic<T> &_q_value, T newValue) Q_DECL_NOTHROW
+    static T fetchAndStoreRelease(std::atomic<T> &_q_value, T newValue) noexcept
     {
         return _q_value.exchange(newValue, std::memory_order_release);
     }
 
     template <typename T>
-    static T fetchAndStoreOrdered(std::atomic<T> &_q_value, T newValue) Q_DECL_NOTHROW
+    static T fetchAndStoreOrdered(std::atomic<T> &_q_value, T newValue) noexcept
     {
         return _q_value.exchange(newValue, std::memory_order_acq_rel);
     }
 
-    static inline Q_DECL_CONSTEXPR bool isFetchAndAddNative() Q_DECL_NOTHROW { return isTestAndSetNative(); }
-    static inline Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() Q_DECL_NOTHROW { return false; }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndAddNative() noexcept { return isTestAndSetNative(); }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() noexcept { return false; }
 
     template <typename T> static inline
-    T fetchAndAddRelaxed(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddRelaxed(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_add(valueToAdd, std::memory_order_relaxed);
     }
 
     template <typename T> static inline
-    T fetchAndAddAcquire(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddAcquire(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_add(valueToAdd, std::memory_order_acquire);
     }
 
     template <typename T> static inline
-    T fetchAndAddRelease(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddRelease(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_add(valueToAdd, std::memory_order_release);
     }
 
     template <typename T> static inline
-    T fetchAndAddOrdered(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddOrdered(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_add(valueToAdd, std::memory_order_acq_rel);
     }
 
     template <typename T> static inline
-    T fetchAndSubRelaxed(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndSubRelaxed(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_sub(valueToAdd, std::memory_order_relaxed);
     }
 
     template <typename T> static inline
-    T fetchAndSubAcquire(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndSubAcquire(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_sub(valueToAdd, std::memory_order_acquire);
     }
 
     template <typename T> static inline
-    T fetchAndSubRelease(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndSubRelease(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_sub(valueToAdd, std::memory_order_release);
     }
 
     template <typename T> static inline
-    T fetchAndSubOrdered(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndSubOrdered(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_sub(valueToAdd, std::memory_order_acq_rel);
     }
 
     template <typename T> static inline
-    T fetchAndAndRelaxed(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAndRelaxed(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_and(valueToAdd, std::memory_order_relaxed);
     }
 
     template <typename T> static inline
-    T fetchAndAndAcquire(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAndAcquire(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_and(valueToAdd, std::memory_order_acquire);
     }
 
     template <typename T> static inline
-    T fetchAndAndRelease(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAndRelease(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_and(valueToAdd, std::memory_order_release);
     }
 
     template <typename T> static inline
-    T fetchAndAndOrdered(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAndOrdered(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_and(valueToAdd, std::memory_order_acq_rel);
     }
 
     template <typename T> static inline
-    T fetchAndOrRelaxed(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndOrRelaxed(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_or(valueToAdd, std::memory_order_relaxed);
     }
 
     template <typename T> static inline
-    T fetchAndOrAcquire(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndOrAcquire(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_or(valueToAdd, std::memory_order_acquire);
     }
 
     template <typename T> static inline
-    T fetchAndOrRelease(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndOrRelease(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_or(valueToAdd, std::memory_order_release);
     }
 
     template <typename T> static inline
-    T fetchAndOrOrdered(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndOrOrdered(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_or(valueToAdd, std::memory_order_acq_rel);
     }
 
     template <typename T> static inline
-    T fetchAndXorRelaxed(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndXorRelaxed(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_xor(valueToAdd, std::memory_order_relaxed);
     }
 
     template <typename T> static inline
-    T fetchAndXorAcquire(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndXorAcquire(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_xor(valueToAdd, std::memory_order_acquire);
     }
 
     template <typename T> static inline
-    T fetchAndXorRelease(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndXorRelease(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_xor(valueToAdd, std::memory_order_release);
     }
 
     template <typename T> static inline
-    T fetchAndXorOrdered(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndXorOrdered(std::atomic<T> &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         return _q_value.fetch_xor(valueToAdd, std::memory_order_acq_rel);
     }
diff --git a/src/corelib/thread/qatomic_msvc.h b/src/corelib/thread/qatomic_msvc.h
index 5eae2bdc48..67b5224cd7 100644
--- a/src/corelib/thread/qatomic_msvc.h
+++ b/src/corelib/thread/qatomic_msvc.h
@@ -269,24 +269,24 @@ template <> struct QAtomicWindowsType<4> { typedef long Type; };
 
 template <int N> struct QAtomicOpsBySize : QGenericAtomicOps<QAtomicOpsBySize<N> >
 {
-    static inline Q_DECL_CONSTEXPR bool isReferenceCountingNative() Q_DECL_NOTHROW { return true; }
-    static inline Q_DECL_CONSTEXPR bool isReferenceCountingWaitFree() Q_DECL_NOTHROW { return true; }
-    template <typename T> static bool ref(T &_q_value) Q_DECL_NOTHROW;
-    template <typename T> static bool deref(T &_q_value) Q_DECL_NOTHROW;
-
-    static inline Q_DECL_CONSTEXPR bool isTestAndSetNative() Q_DECL_NOTHROW { return true; }
-    static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() Q_DECL_NOTHROW { return true; }
-    template <typename T> static bool testAndSetRelaxed(T &_q_value, T expectedValue, T newValue) Q_DECL_NOTHROW;
+    static inline Q_DECL_CONSTEXPR bool isReferenceCountingNative() noexcept { return true; }
+    static inline Q_DECL_CONSTEXPR bool isReferenceCountingWaitFree() noexcept { return true; }
+    template <typename T> static bool ref(T &_q_value) noexcept;
+    template <typename T> static bool deref(T &_q_value) noexcept;
+
+    static inline Q_DECL_CONSTEXPR bool isTestAndSetNative() noexcept { return true; }
+    static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() noexcept { return true; }
+    template <typename T> static bool testAndSetRelaxed(T &_q_value, T expectedValue, T newValue) noexcept;
     template <typename T>
-    static bool testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue) Q_DECL_NOTHROW;
+    static bool testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue) noexcept;
 
-    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreNative() Q_DECL_NOTHROW { return true; }
-    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() Q_DECL_NOTHROW { return true; }
-    template <typename T> static T fetchAndStoreRelaxed(T &_q_value, T newValue) Q_DECL_NOTHROW;
+    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreNative() noexcept { return true; }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() noexcept { return true; }
+    template <typename T> static T fetchAndStoreRelaxed(T &_q_value, T newValue) noexcept;
 
-    static inline Q_DECL_CONSTEXPR bool isFetchAndAddNative() Q_DECL_NOTHROW { return true; }
-    static inline Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() Q_DECL_NOTHROW { return true; }
-    template <typename T> static T fetchAndAddRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW;
+    static inline Q_DECL_CONSTEXPR bool isFetchAndAddNative() noexcept { return true; }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() noexcept { return true; }
+    template <typename T> static T fetchAndAddRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept;
 
 private:
     typedef typename QAtomicWindowsType<N>::Type Type;
@@ -303,76 +303,76 @@ struct QAtomicOps : QAtomicOpsBySize<sizeof(T)>
 };
 
 template<> template<typename T>
-inline bool QAtomicOpsBySize<4>::ref(T &_q_value) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<4>::ref(T &_q_value) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(Increment)(atomic(&_q_value)) != 0;
 }
 
 template<> template<typename T>
-inline bool QAtomicOpsBySize<4>::deref(T &_q_value) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<4>::deref(T &_q_value) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(Decrement)(atomic(&_q_value)) != 0;
 }
 
 template<> template<typename T>
-inline bool QAtomicOpsBySize<4>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<4>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(CompareExchange)(atomic(&_q_value), value(newValue), value(expectedValue)) == value(expectedValue);
 }
 
 template<> template <typename T>
-inline bool QAtomicOpsBySize<4>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<4>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue) noexcept
 {
     *currentValue = T(QT_INTERLOCKED_FUNCTION(CompareExchange)(atomic(&_q_value), newValue, expectedValue));
     return *currentValue == expectedValue;
 }
 
 template<> template<typename T>
-inline T QAtomicOpsBySize<4>::fetchAndStoreRelaxed(T &_q_value, T newValue) Q_DECL_NOTHROW
+inline T QAtomicOpsBySize<4>::fetchAndStoreRelaxed(T &_q_value, T newValue) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(Exchange)(atomic(&_q_value), value(newValue));
 }
 
 template<> template<typename T>
-inline T QAtomicOpsBySize<4>::fetchAndAddRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+inline T QAtomicOpsBySize<4>::fetchAndAddRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(ExchangeAdd)(atomic(&_q_value), value<T>(valueToAdd * QAtomicAdditiveType<T>::AddScale));
 }
 
 #ifdef Q_ATOMIC_INT16_IS_SUPPORTED
 template<> template<typename T>
-inline bool QAtomicOpsBySize<2>::ref(T &_q_value) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<2>::ref(T &_q_value) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(Increment16)(atomic(&_q_value)) != 0;
 }
 
 template<> template<typename T>
-inline bool QAtomicOpsBySize<2>::deref(T &_q_value) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<2>::deref(T &_q_value) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(Decrement16)(atomic(&_q_value)) != 0;
 }
 
 template<> template<typename T>
-inline bool QAtomicOpsBySize<2>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<2>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(CompareExchange16)(atomic(&_q_value), value(newValue), value(expectedValue)) == value(expectedValue);
 }
 
 template<> template <typename T>
-inline bool QAtomicOpsBySize<2>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<2>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue) noexcept
 {
     *currentValue = T(QT_INTERLOCKED_FUNCTION(CompareExchange16)(atomic(&_q_value), newValue, expectedValue));
     return *currentValue == expectedValue;
 }
 
 template<> template<typename T>
-inline T QAtomicOpsBySize<2>::fetchAndStoreRelaxed(T &_q_value, T newValue) Q_DECL_NOTHROW
+inline T QAtomicOpsBySize<2>::fetchAndStoreRelaxed(T &_q_value, T newValue) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(Exchange16)(atomic(&_q_value), value(newValue));
 }
 
 template<> template<typename T>
-inline T QAtomicOpsBySize<2>::fetchAndAddRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+inline T QAtomicOpsBySize<2>::fetchAndAddRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(ExchangeAdd16)(atomic(&_q_value), value<T>(valueToAdd * QAtomicAdditiveType<T>::AddScale));
 }
@@ -380,38 +380,38 @@ inline T QAtomicOpsBySize<2>::fetchAndAddRelaxed(T &_q_value, typename QAtomicAd
 
 #ifdef Q_ATOMIC_INT64_IS_SUPPORTED
 template<> template<typename T>
-inline bool QAtomicOpsBySize<8>::ref(T &_q_value) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<8>::ref(T &_q_value) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(Increment64)(atomic(&_q_value)) != 0;
 }
 
 template<> template<typename T>
-inline bool QAtomicOpsBySize<8>::deref(T &_q_value) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<8>::deref(T &_q_value) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(Decrement64)(atomic(&_q_value)) != 0;
 }
 
 template<> template<typename T>
-inline bool QAtomicOpsBySize<8>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<8>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(CompareExchange64)(atomic(&_q_value), value(newValue), value(expectedValue)) == value(expectedValue);
 }
 
 template<> template <typename T>
-inline bool QAtomicOpsBySize<8>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue) Q_DECL_NOTHROW
+inline bool QAtomicOpsBySize<8>::testAndSetRelaxed(T &_q_value, T expectedValue, T newValue, T *currentValue) noexcept
 {
     *currentValue = T(QT_INTERLOCKED_FUNCTION(CompareExchange64)(atomic(&_q_value), newValue, expectedValue));
     return *currentValue == expectedValue;
 }
 
 template<> template<typename T>
-inline T QAtomicOpsBySize<8>::fetchAndStoreRelaxed(T &_q_value, T newValue) Q_DECL_NOTHROW
+inline T QAtomicOpsBySize<8>::fetchAndStoreRelaxed(T &_q_value, T newValue) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(Exchange64)(atomic(&_q_value), value(newValue));
 }
 
 template<> template<typename T>
-inline T QAtomicOpsBySize<8>::fetchAndAddRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+inline T QAtomicOpsBySize<8>::fetchAndAddRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
 {
     return QT_INTERLOCKED_FUNCTION(ExchangeAdd64)(atomic(&_q_value), value<T>(valueToAdd * QAtomicAdditiveType<T>::AddScale));
 }
@@ -423,41 +423,41 @@ struct QAtomicOps<T *> : QGenericAtomicOps<QAtomicOps<T *> >
 {
     typedef T *Type;
 
-    static inline Q_DECL_CONSTEXPR bool isTestAndSetNative() Q_DECL_NOTHROW { return true; }
-    static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() Q_DECL_NOTHROW { return true; }
-    static bool testAndSetRelaxed(T *&_q_value, T *expectedValue, T *newValue) Q_DECL_NOTHROW;
-    static bool testAndSetRelaxed(T *&_q_value, T *expectedValue, T *newValue, T **currentValue) Q_DECL_NOTHROW;
+    static inline Q_DECL_CONSTEXPR bool isTestAndSetNative() noexcept { return true; }
+    static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() noexcept { return true; }
+    static bool testAndSetRelaxed(T *&_q_value, T *expectedValue, T *newValue) noexcept;
+    static bool testAndSetRelaxed(T *&_q_value, T *expectedValue, T *newValue, T **currentValue) noexcept;
 
-    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreNative() Q_DECL_NOTHROW { return true; }
-    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() Q_DECL_NOTHROW { return true; }
-    static T *fetchAndStoreRelaxed(T *&_q_value, T *newValue) Q_DECL_NOTHROW;
+    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreNative() noexcept { return true; }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() noexcept { return true; }
+    static T *fetchAndStoreRelaxed(T *&_q_value, T *newValue) noexcept;
 
-    static inline Q_DECL_CONSTEXPR bool isFetchAndAddNative() Q_DECL_NOTHROW { return true; }
-    static inline Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() Q_DECL_NOTHROW { return true; }
-    static T *fetchAndAddRelaxed(T *&_q_value, qptrdiff valueToAdd) Q_DECL_NOTHROW;
+    static inline Q_DECL_CONSTEXPR bool isFetchAndAddNative() noexcept { return true; }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() noexcept { return true; }
+    static T *fetchAndAddRelaxed(T *&_q_value, qptrdiff valueToAdd) noexcept;
 };
 
 template <typename T>
-inline bool QAtomicOps<T *>::testAndSetRelaxed(T *&_q_value, T *expectedValue, T *newValue) Q_DECL_NOTHROW
+inline bool QAtomicOps<T *>::testAndSetRelaxed(T *&_q_value, T *expectedValue, T *newValue) noexcept
 {
     return QT_INTERLOCKED_COMPARE_EXCHANGE_POINTER(&_q_value, newValue, expectedValue) == expectedValue;
 }
 
 template <typename T>
-inline bool QAtomicOps<T *>::testAndSetRelaxed(T *&_q_value, T *expectedValue, T *newValue, T **currentValue) Q_DECL_NOTHROW
+inline bool QAtomicOps<T *>::testAndSetRelaxed(T *&_q_value, T *expectedValue, T *newValue, T **currentValue) noexcept
 {
     *currentValue = reinterpret_cast<T *>(QT_INTERLOCKED_COMPARE_EXCHANGE_POINTER(&_q_value, newValue, expectedValue));
     return *currentValue == expectedValue;
 }
 
 template <typename T>
-inline T *QAtomicOps<T *>::fetchAndStoreRelaxed(T *&_q_value, T *newValue) Q_DECL_NOTHROW
+inline T *QAtomicOps<T *>::fetchAndStoreRelaxed(T *&_q_value, T *newValue) noexcept
 {
     return reinterpret_cast<T *>(QT_INTERLOCKED_EXCHANGE_POINTER(&_q_value, newValue));
 }
 
 template <typename T>
-inline T *QAtomicOps<T *>::fetchAndAddRelaxed(T *&_q_value, qptrdiff valueToAdd) Q_DECL_NOTHROW
+inline T *QAtomicOps<T *>::fetchAndAddRelaxed(T *&_q_value, qptrdiff valueToAdd) noexcept
 {
     return reinterpret_cast<T *>(QT_INTERLOCKED_EXCHANGE_ADD_POINTER(&_q_value, valueToAdd * sizeof(T)));
 }
diff --git a/src/corelib/thread/qbasicatomic.h b/src/corelib/thread/qbasicatomic.h
index a0304697b8..ad6cba04dd 100644
--- a/src/corelib/thread/qbasicatomic.h
+++ b/src/corelib/thread/qbasicatomic.h
@@ -100,125 +100,125 @@ public:
 
     // Everything below is either implemented in ../arch/qatomic_XXX.h or (as fallback) in qgenericatomic.h
 
-    T load() const Q_DECL_NOTHROW { return Ops::load(_q_value); }
-    void store(T newValue) Q_DECL_NOTHROW { Ops::store(_q_value, newValue); }
+    T load() const noexcept { return Ops::load(_q_value); }
+    void store(T newValue) noexcept { Ops::store(_q_value, newValue); }
 
-    T loadAcquire() const Q_DECL_NOTHROW { return Ops::loadAcquire(_q_value); }
-    void storeRelease(T newValue) Q_DECL_NOTHROW { Ops::storeRelease(_q_value, newValue); }
-    operator T() const Q_DECL_NOTHROW { return loadAcquire(); }
-    T operator=(T newValue) Q_DECL_NOTHROW { storeRelease(newValue); return newValue; }
+    T loadAcquire() const noexcept { return Ops::loadAcquire(_q_value); }
+    void storeRelease(T newValue) noexcept { Ops::storeRelease(_q_value, newValue); }
+    operator T() const noexcept { return loadAcquire(); }
+    T operator=(T newValue) noexcept { storeRelease(newValue); return newValue; }
 
-    static Q_DECL_CONSTEXPR bool isReferenceCountingNative() Q_DECL_NOTHROW { return Ops::isReferenceCountingNative(); }
-    static Q_DECL_CONSTEXPR bool isReferenceCountingWaitFree() Q_DECL_NOTHROW { return Ops::isReferenceCountingWaitFree(); }
+    static Q_DECL_CONSTEXPR bool isReferenceCountingNative() noexcept { return Ops::isReferenceCountingNative(); }
+    static Q_DECL_CONSTEXPR bool isReferenceCountingWaitFree() noexcept { return Ops::isReferenceCountingWaitFree(); }
 
-    bool ref() Q_DECL_NOTHROW { return Ops::ref(_q_value); }
-    bool deref() Q_DECL_NOTHROW { return Ops::deref(_q_value); }
+    bool ref() noexcept { return Ops::ref(_q_value); }
+    bool deref() noexcept { return Ops::deref(_q_value); }
 
-    static Q_DECL_CONSTEXPR bool isTestAndSetNative() Q_DECL_NOTHROW { return Ops::isTestAndSetNative(); }
-    static Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() Q_DECL_NOTHROW { return Ops::isTestAndSetWaitFree(); }
+    static Q_DECL_CONSTEXPR bool isTestAndSetNative() noexcept { return Ops::isTestAndSetNative(); }
+    static Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() noexcept { return Ops::isTestAndSetWaitFree(); }
 
-    bool testAndSetRelaxed(T expectedValue, T newValue) Q_DECL_NOTHROW
+    bool testAndSetRelaxed(T expectedValue, T newValue) noexcept
     { return Ops::testAndSetRelaxed(_q_value, expectedValue, newValue); }
-    bool testAndSetAcquire(T expectedValue, T newValue) Q_DECL_NOTHROW
+    bool testAndSetAcquire(T expectedValue, T newValue) noexcept
     { return Ops::testAndSetAcquire(_q_value, expectedValue, newValue); }
-    bool testAndSetRelease(T expectedValue, T newValue) Q_DECL_NOTHROW
+    bool testAndSetRelease(T expectedValue, T newValue) noexcept
     { return Ops::testAndSetRelease(_q_value, expectedValue, newValue); }
-    bool testAndSetOrdered(T expectedValue, T newValue) Q_DECL_NOTHROW
+    bool testAndSetOrdered(T expectedValue, T newValue) noexcept
     { return Ops::testAndSetOrdered(_q_value, expectedValue, newValue); }
 
-    bool testAndSetRelaxed(T expectedValue, T newValue, T &currentValue) Q_DECL_NOTHROW
+    bool testAndSetRelaxed(T expectedValue, T newValue, T &currentValue) noexcept
     { return Ops::testAndSetRelaxed(_q_value, expectedValue, newValue, &currentValue); }
-    bool testAndSetAcquire(T expectedValue, T newValue, T &currentValue) Q_DECL_NOTHROW
+    bool testAndSetAcquire(T expectedValue, T newValue, T &currentValue) noexcept
     { return Ops::testAndSetAcquire(_q_value, expectedValue, newValue, &currentValue); }
-    bool testAndSetRelease(T expectedValue, T newValue, T &currentValue) Q_DECL_NOTHROW
+    bool testAndSetRelease(T expectedValue, T newValue, T &currentValue) noexcept
     { return Ops::testAndSetRelease(_q_value, expectedValue, newValue, &currentValue); }
-    bool testAndSetOrdered(T expectedValue, T newValue, T &currentValue) Q_DECL_NOTHROW
+    bool testAndSetOrdered(T expectedValue, T newValue, T &currentValue) noexcept
     { return Ops::testAndSetOrdered(_q_value, expectedValue, newValue, &currentValue); }
 
-    static Q_DECL_CONSTEXPR bool isFetchAndStoreNative() Q_DECL_NOTHROW { return Ops::isFetchAndStoreNative(); }
-    static Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() Q_DECL_NOTHROW { return Ops::isFetchAndStoreWaitFree(); }
+    static Q_DECL_CONSTEXPR bool isFetchAndStoreNative() noexcept { return Ops::isFetchAndStoreNative(); }
+    static Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() noexcept { return Ops::isFetchAndStoreWaitFree(); }
 
-    T fetchAndStoreRelaxed(T newValue) Q_DECL_NOTHROW
+    T fetchAndStoreRelaxed(T newValue) noexcept
     { return Ops::fetchAndStoreRelaxed(_q_value, newValue); }
-    T fetchAndStoreAcquire(T newValue) Q_DECL_NOTHROW
+    T fetchAndStoreAcquire(T newValue) noexcept
     { return Ops::fetchAndStoreAcquire(_q_value, newValue); }
-    T fetchAndStoreRelease(T newValue) Q_DECL_NOTHROW
+    T fetchAndStoreRelease(T newValue) noexcept
     { return Ops::fetchAndStoreRelease(_q_value, newValue); }
-    T fetchAndStoreOrdered(T newValue) Q_DECL_NOTHROW
+    T fetchAndStoreOrdered(T newValue) noexcept
     { return Ops::fetchAndStoreOrdered(_q_value, newValue); }
 
-    static Q_DECL_CONSTEXPR bool isFetchAndAddNative() Q_DECL_NOTHROW { return Ops::isFetchAndAddNative(); }
-    static Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() Q_DECL_NOTHROW { return Ops::isFetchAndAddWaitFree(); }
+    static Q_DECL_CONSTEXPR bool isFetchAndAddNative() noexcept { return Ops::isFetchAndAddNative(); }
+    static Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() noexcept { return Ops::isFetchAndAddWaitFree(); }
 
-    T fetchAndAddRelaxed(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddRelaxed(T valueToAdd) noexcept
     { return Ops::fetchAndAddRelaxed(_q_value, valueToAdd); }
-    T fetchAndAddAcquire(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddAcquire(T valueToAdd) noexcept
     { return Ops::fetchAndAddAcquire(_q_value, valueToAdd); }
-    T fetchAndAddRelease(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddRelease(T valueToAdd) noexcept
     { return Ops::fetchAndAddRelease(_q_value, valueToAdd); }
-    T fetchAndAddOrdered(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddOrdered(T valueToAdd) noexcept
     { return Ops::fetchAndAddOrdered(_q_value, valueToAdd); }
 
-    T fetchAndSubRelaxed(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndSubRelaxed(T valueToAdd) noexcept
     { return Ops::fetchAndSubRelaxed(_q_value, valueToAdd); }
-    T fetchAndSubAcquire(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndSubAcquire(T valueToAdd) noexcept
     { return Ops::fetchAndSubAcquire(_q_value, valueToAdd); }
-    T fetchAndSubRelease(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndSubRelease(T valueToAdd) noexcept
     { return Ops::fetchAndSubRelease(_q_value, valueToAdd); }
-    T fetchAndSubOrdered(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndSubOrdered(T valueToAdd) noexcept
     { return Ops::fetchAndSubOrdered(_q_value, valueToAdd); }
 
-    T fetchAndAndRelaxed(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAndRelaxed(T valueToAdd) noexcept
     { return Ops::fetchAndAndRelaxed(_q_value, valueToAdd); }
-    T fetchAndAndAcquire(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAndAcquire(T valueToAdd) noexcept
     { return Ops::fetchAndAndAcquire(_q_value, valueToAdd); }
-    T fetchAndAndRelease(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAndRelease(T valueToAdd) noexcept
     { return Ops::fetchAndAndRelease(_q_value, valueToAdd); }
-    T fetchAndAndOrdered(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAndOrdered(T valueToAdd) noexcept
     { return Ops::fetchAndAndOrdered(_q_value, valueToAdd); }
 
-    T fetchAndOrRelaxed(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndOrRelaxed(T valueToAdd) noexcept
     { return Ops::fetchAndOrRelaxed(_q_value, valueToAdd); }
-    T fetchAndOrAcquire(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndOrAcquire(T valueToAdd) noexcept
     { return Ops::fetchAndOrAcquire(_q_value, valueToAdd); }
-    T fetchAndOrRelease(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndOrRelease(T valueToAdd) noexcept
     { return Ops::fetchAndOrRelease(_q_value, valueToAdd); }
-    T fetchAndOrOrdered(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndOrOrdered(T valueToAdd) noexcept
     { return Ops::fetchAndOrOrdered(_q_value, valueToAdd); }
 
-    T fetchAndXorRelaxed(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndXorRelaxed(T valueToAdd) noexcept
     { return Ops::fetchAndXorRelaxed(_q_value, valueToAdd); }
-    T fetchAndXorAcquire(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndXorAcquire(T valueToAdd) noexcept
     { return Ops::fetchAndXorAcquire(_q_value, valueToAdd); }
-    T fetchAndXorRelease(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndXorRelease(T valueToAdd) noexcept
     { return Ops::fetchAndXorRelease(_q_value, valueToAdd); }
-    T fetchAndXorOrdered(T valueToAdd) Q_DECL_NOTHROW
+    T fetchAndXorOrdered(T valueToAdd) noexcept
     { return Ops::fetchAndXorOrdered(_q_value, valueToAdd); }
 
-    T operator++() Q_DECL_NOTHROW
+    T operator++() noexcept
     { return fetchAndAddOrdered(1) + 1; }
-    T operator++(int) Q_DECL_NOTHROW
+    T operator++(int) noexcept
     { return fetchAndAddOrdered(1); }
-    T operator--() Q_DECL_NOTHROW
+    T operator--() noexcept
     { return fetchAndSubOrdered(1) - 1; }
-    T operator--(int) Q_DECL_NOTHROW
+    T operator--(int) noexcept
     { return fetchAndSubOrdered(1); }
 
-    T operator+=(T v) Q_DECL_NOTHROW
+    T operator+=(T v) noexcept
     { return fetchAndAddOrdered(v) + v; }
-    T operator-=(T v) Q_DECL_NOTHROW
+    T operator-=(T v) noexcept
     { return fetchAndSubOrdered(v) - v; }
-    T operator&=(T v) Q_DECL_NOTHROW
+    T operator&=(T v) noexcept
     { return fetchAndAndOrdered(v) & v; }
-    T operator|=(T v) Q_DECL_NOTHROW
+    T operator|=(T v) noexcept
     { return fetchAndOrOrdered(v) | v; }
-    T operator^=(T v) Q_DECL_NOTHROW
+    T operator^=(T v) noexcept
     { return fetchAndXorOrdered(v) ^ v; }
 
 
 #ifdef QT_BASIC_ATOMIC_HAS_CONSTRUCTORS
     QBasicAtomicInteger() = default;
-    constexpr QBasicAtomicInteger(T value) Q_DECL_NOTHROW : _q_value(value) {}
+    constexpr QBasicAtomicInteger(T value) noexcept : _q_value(value) {}
     QBasicAtomicInteger(const QBasicAtomicInteger &) = delete;
     QBasicAtomicInteger &operator=(const QBasicAtomicInteger &) = delete;
     QBasicAtomicInteger &operator=(const QBasicAtomicInteger &) volatile = delete;
@@ -236,85 +236,85 @@ public:
 
     AtomicType _q_value;
 
-    Type load() const Q_DECL_NOTHROW { return Ops::load(_q_value); }
-    void store(Type newValue) Q_DECL_NOTHROW { Ops::store(_q_value, newValue); }
-    operator Type() const Q_DECL_NOTHROW { return loadAcquire(); }
-    Type operator=(Type newValue) Q_DECL_NOTHROW { storeRelease(newValue); return newValue; }
+    Type load() const noexcept { return Ops::load(_q_value); }
+    void store(Type newValue) noexcept { Ops::store(_q_value, newValue); }
+    operator Type() const noexcept { return loadAcquire(); }
+    Type operator=(Type newValue) noexcept { storeRelease(newValue); return newValue; }
 
     // Atomic API, implemented in qatomic_XXX.h
-    Type loadAcquire() const Q_DECL_NOTHROW { return Ops::loadAcquire(_q_value); }
-    void storeRelease(Type newValue) Q_DECL_NOTHROW { Ops::storeRelease(_q_value, newValue); }
+    Type loadAcquire() const noexcept { return Ops::loadAcquire(_q_value); }
+    void storeRelease(Type newValue) noexcept { Ops::storeRelease(_q_value, newValue); }
 
-    static Q_DECL_CONSTEXPR bool isTestAndSetNative() Q_DECL_NOTHROW { return Ops::isTestAndSetNative(); }
-    static Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() Q_DECL_NOTHROW { return Ops::isTestAndSetWaitFree(); }
+    static Q_DECL_CONSTEXPR bool isTestAndSetNative() noexcept { return Ops::isTestAndSetNative(); }
+    static Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() noexcept { return Ops::isTestAndSetWaitFree(); }
 
-    bool testAndSetRelaxed(Type expectedValue, Type newValue) Q_DECL_NOTHROW
+    bool testAndSetRelaxed(Type expectedValue, Type newValue) noexcept
     { return Ops::testAndSetRelaxed(_q_value, expectedValue, newValue); }
-    bool testAndSetAcquire(Type expectedValue, Type newValue) Q_DECL_NOTHROW
+    bool testAndSetAcquire(Type expectedValue, Type newValue) noexcept
     { return Ops::testAndSetAcquire(_q_value, expectedValue, newValue); }
-    bool testAndSetRelease(Type expectedValue, Type newValue) Q_DECL_NOTHROW
+    bool testAndSetRelease(Type expectedValue, Type newValue) noexcept
     { return Ops::testAndSetRelease(_q_value, expectedValue, newValue); }
-    bool testAndSetOrdered(Type expectedValue, Type newValue) Q_DECL_NOTHROW
+    bool testAndSetOrdered(Type expectedValue, Type newValue) noexcept
     { return Ops::testAndSetOrdered(_q_value, expectedValue, newValue); }
 
-    bool testAndSetRelaxed(Type expectedValue, Type newValue, Type &currentValue) Q_DECL_NOTHROW
+    bool testAndSetRelaxed(Type expectedValue, Type newValue, Type &currentValue) noexcept
     { return Ops::testAndSetRelaxed(_q_value, expectedValue, newValue, &currentValue); }
-    bool testAndSetAcquire(Type expectedValue, Type newValue, Type &currentValue) Q_DECL_NOTHROW
+    bool testAndSetAcquire(Type expectedValue, Type newValue, Type &currentValue) noexcept
     { return Ops::testAndSetAcquire(_q_value, expectedValue, newValue, &currentValue); }
-    bool testAndSetRelease(Type expectedValue, Type newValue, Type &currentValue) Q_DECL_NOTHROW
+    bool testAndSetRelease(Type expectedValue, Type newValue, Type &currentValue) noexcept
     { return Ops::testAndSetRelease(_q_value, expectedValue, newValue, &currentValue); }
-    bool testAndSetOrdered(Type expectedValue, Type newValue, Type &currentValue) Q_DECL_NOTHROW
+    bool testAndSetOrdered(Type expectedValue, Type newValue, Type &currentValue) noexcept
     { return Ops::testAndSetOrdered(_q_value, expectedValue, newValue, &currentValue); }
 
-    static Q_DECL_CONSTEXPR bool isFetchAndStoreNative() Q_DECL_NOTHROW { return Ops::isFetchAndStoreNative(); }
-    static Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() Q_DECL_NOTHROW { return Ops::isFetchAndStoreWaitFree(); }
+    static Q_DECL_CONSTEXPR bool isFetchAndStoreNative() noexcept { return Ops::isFetchAndStoreNative(); }
+    static Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() noexcept { return Ops::isFetchAndStoreWaitFree(); }
 
-    Type fetchAndStoreRelaxed(Type newValue) Q_DECL_NOTHROW
+    Type fetchAndStoreRelaxed(Type newValue) noexcept
     { return Ops::fetchAndStoreRelaxed(_q_value, newValue); }
-    Type fetchAndStoreAcquire(Type newValue) Q_DECL_NOTHROW
+    Type fetchAndStoreAcquire(Type newValue) noexcept
     { return Ops::fetchAndStoreAcquire(_q_value, newValue); }
-    Type fetchAndStoreRelease(Type newValue) Q_DECL_NOTHROW
+    Type fetchAndStoreRelease(Type newValue) noexcept
     { return Ops::fetchAndStoreRelease(_q_value, newValue); }
-    Type fetchAndStoreOrdered(Type newValue) Q_DECL_NOTHROW
+    Type fetchAndStoreOrdered(Type newValue) noexcept
     { return Ops::fetchAndStoreOrdered(_q_value, newValue); }
 
-    static Q_DECL_CONSTEXPR bool isFetchAndAddNative() Q_DECL_NOTHROW { return Ops::isFetchAndAddNative(); }
-    static Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() Q_DECL_NOTHROW { return Ops::isFetchAndAddWaitFree(); }
+    static Q_DECL_CONSTEXPR bool isFetchAndAddNative() noexcept { return Ops::isFetchAndAddNative(); }
+    static Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() noexcept { return Ops::isFetchAndAddWaitFree(); }
 
-    Type fetchAndAddRelaxed(qptrdiff valueToAdd) Q_DECL_NOTHROW
+    Type fetchAndAddRelaxed(qptrdiff valueToAdd) noexcept
     { return Ops::fetchAndAddRelaxed(_q_value, valueToAdd); }
-    Type fetchAndAddAcquire(qptrdiff valueToAdd) Q_DECL_NOTHROW
+    Type fetchAndAddAcquire(qptrdiff valueToAdd) noexcept
     { return Ops::fetchAndAddAcquire(_q_value, valueToAdd); }
-    Type fetchAndAddRelease(qptrdiff valueToAdd) Q_DECL_NOTHROW
+    Type fetchAndAddRelease(qptrdiff valueToAdd) noexcept
     { return Ops::fetchAndAddRelease(_q_value, valueToAdd); }
-    Type fetchAndAddOrdered(qptrdiff valueToAdd) Q_DECL_NOTHROW
+    Type fetchAndAddOrdered(qptrdiff valueToAdd) noexcept
     { return Ops::fetchAndAddOrdered(_q_value, valueToAdd); }
 
-    Type fetchAndSubRelaxed(qptrdiff valueToAdd) Q_DECL_NOTHROW
+    Type fetchAndSubRelaxed(qptrdiff valueToAdd) noexcept
     { return Ops::fetchAndSubRelaxed(_q_value, valueToAdd); }
-    Type fetchAndSubAcquire(qptrdiff valueToAdd) Q_DECL_NOTHROW
+    Type fetchAndSubAcquire(qptrdiff valueToAdd) noexcept
     { return Ops::fetchAndSubAcquire(_q_value, valueToAdd); }
-    Type fetchAndSubRelease(qptrdiff valueToAdd) Q_DECL_NOTHROW
+    Type fetchAndSubRelease(qptrdiff valueToAdd) noexcept
     { return Ops::fetchAndSubRelease(_q_value, valueToAdd); }
-    Type fetchAndSubOrdered(qptrdiff valueToAdd) Q_DECL_NOTHROW
+    Type fetchAndSubOrdered(qptrdiff valueToAdd) noexcept
     { return Ops::fetchAndSubOrdered(_q_value, valueToAdd); }
 
-    Type operator++() Q_DECL_NOTHROW
+    Type operator++() noexcept
     { return fetchAndAddOrdered(1) + 1; }
-    Type operator++(int) Q_DECL_NOTHROW
+    Type operator++(int) noexcept
     { return fetchAndAddOrdered(1); }
-    Type operator--() Q_DECL_NOTHROW
+    Type operator--() noexcept
     { return fetchAndSubOrdered(1) - 1; }
-    Type operator--(int) Q_DECL_NOTHROW
+    Type operator--(int) noexcept
     { return fetchAndSubOrdered(1); }
-    Type operator+=(qptrdiff valueToAdd) Q_DECL_NOTHROW
+    Type operator+=(qptrdiff valueToAdd) noexcept
     { return fetchAndAddOrdered(valueToAdd) + valueToAdd; }
-    Type operator-=(qptrdiff valueToSub) Q_DECL_NOTHROW
+    Type operator-=(qptrdiff valueToSub) noexcept
     { return fetchAndSubOrdered(valueToSub) - valueToSub; }
 
 #ifdef QT_BASIC_ATOMIC_HAS_CONSTRUCTORS
     QBasicAtomicPointer() = default;
-    constexpr QBasicAtomicPointer(Type value) Q_DECL_NOTHROW : _q_value(value) {}
+    constexpr QBasicAtomicPointer(Type value) noexcept : _q_value(value) {}
     QBasicAtomicPointer(const QBasicAtomicPointer &) = delete;
     QBasicAtomicPointer &operator=(const QBasicAtomicPointer &) = delete;
     QBasicAtomicPointer &operator=(const QBasicAtomicPointer &) volatile = delete;
diff --git a/src/corelib/thread/qfutex_p.h b/src/corelib/thread/qfutex_p.h
index 483664c783..136f6bca8c 100644
--- a/src/corelib/thread/qfutex_p.h
+++ b/src/corelib/thread/qfutex_p.h
@@ -85,7 +85,7 @@ QT_BEGIN_NAMESPACE
 namespace QtLinuxFutex {
     constexpr inline bool futexAvailable() { return true; }
     inline int _q_futex(int *addr, int op, int val, quintptr val2 = 0,
-                        int *addr2 = nullptr, int val3 = 0) Q_DECL_NOTHROW
+                        int *addr2 = nullptr, int val3 = 0) noexcept
     {
         // we use __NR_futex because some libcs (like Android's bionic) don't
         // provide SYS_futex etc.
diff --git a/src/corelib/thread/qgenericatomic.h b/src/corelib/thread/qgenericatomic.h
index 89c4fe9a11..f8333e7de6 100644
--- a/src/corelib/thread/qgenericatomic.h
+++ b/src/corelib/thread/qgenericatomic.h
@@ -72,32 +72,32 @@ template <typename BaseClass> struct QGenericAtomicOps
 {
     template <typename T> struct AtomicType { typedef T Type; typedef T *PointerType; };
 
-    template <typename T> static void acquireMemoryFence(const T &_q_value) Q_DECL_NOTHROW
+    template <typename T> static void acquireMemoryFence(const T &_q_value) noexcept
     {
         BaseClass::orderedMemoryFence(_q_value);
     }
-    template <typename T> static void releaseMemoryFence(const T &_q_value) Q_DECL_NOTHROW
+    template <typename T> static void releaseMemoryFence(const T &_q_value) noexcept
     {
         BaseClass::orderedMemoryFence(_q_value);
     }
-    template <typename T> static void orderedMemoryFence(const T &) Q_DECL_NOTHROW
+    template <typename T> static void orderedMemoryFence(const T &) noexcept
     {
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T load(const T &_q_value) Q_DECL_NOTHROW
+    T load(const T &_q_value) noexcept
     {
         return _q_value;
     }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    void store(T &_q_value, X newValue) Q_DECL_NOTHROW
+    void store(T &_q_value, X newValue) noexcept
     {
         _q_value = newValue;
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T loadAcquire(const T &_q_value) Q_DECL_NOTHROW
+    T loadAcquire(const T &_q_value) noexcept
     {
         T tmp = *static_cast<const volatile T *>(&_q_value);
         BaseClass::acquireMemoryFence(_q_value);
@@ -105,24 +105,24 @@ template <typename BaseClass> struct QGenericAtomicOps
     }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    void storeRelease(T &_q_value, X newValue) Q_DECL_NOTHROW
+    void storeRelease(T &_q_value, X newValue) noexcept
     {
         BaseClass::releaseMemoryFence(_q_value);
         *static_cast<volatile T *>(&_q_value) = newValue;
     }
 
-    static inline Q_DECL_CONSTEXPR bool isReferenceCountingNative() Q_DECL_NOTHROW
+    static inline Q_DECL_CONSTEXPR bool isReferenceCountingNative() noexcept
     { return BaseClass::isFetchAndAddNative(); }
-    static inline Q_DECL_CONSTEXPR bool isReferenceCountingWaitFree() Q_DECL_NOTHROW
+    static inline Q_DECL_CONSTEXPR bool isReferenceCountingWaitFree() noexcept
     { return BaseClass::isFetchAndAddWaitFree(); }
     template <typename T> static Q_ALWAYS_INLINE
-    bool ref(T &_q_value) Q_DECL_NOTHROW
+    bool ref(T &_q_value) noexcept
     {
         return BaseClass::fetchAndAddRelaxed(_q_value, 1) != T(-1);
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    bool deref(T &_q_value) Q_DECL_NOTHROW
+    bool deref(T &_q_value) noexcept
     {
          return BaseClass::fetchAndAddRelaxed(_q_value, -1) != 1;
     }
@@ -130,16 +130,16 @@ template <typename BaseClass> struct QGenericAtomicOps
 #if 0
     // These functions have no default implementation
     // Archictectures must implement them
-    static inline Q_DECL_CONSTEXPR bool isTestAndSetNative() Q_DECL_NOTHROW;
-    static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() Q_DECL_NOTHROW;
+    static inline Q_DECL_CONSTEXPR bool isTestAndSetNative() noexcept;
+    static inline Q_DECL_CONSTEXPR bool isTestAndSetWaitFree() noexcept;
     template <typename T, typename X> static inline
-    bool testAndSetRelaxed(T &_q_value, X expectedValue, X newValue) Q_DECL_NOTHROW;
+    bool testAndSetRelaxed(T &_q_value, X expectedValue, X newValue) noexcept;
     template <typename T, typename X> static inline
-    bool testAndSetRelaxed(T &_q_value, X expectedValue, X newValue, X *currentValue) Q_DECL_NOTHROW;
+    bool testAndSetRelaxed(T &_q_value, X expectedValue, X newValue, X *currentValue) noexcept;
 #endif
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    bool testAndSetAcquire(T &_q_value, X expectedValue, X newValue) Q_DECL_NOTHROW
+    bool testAndSetAcquire(T &_q_value, X expectedValue, X newValue) noexcept
     {
         bool tmp = BaseClass::testAndSetRelaxed(_q_value, expectedValue, newValue);
         BaseClass::acquireMemoryFence(_q_value);
@@ -147,21 +147,21 @@ template <typename BaseClass> struct QGenericAtomicOps
     }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    bool testAndSetRelease(T &_q_value, X expectedValue, X newValue) Q_DECL_NOTHROW
+    bool testAndSetRelease(T &_q_value, X expectedValue, X newValue) noexcept
     {
         BaseClass::releaseMemoryFence(_q_value);
         return BaseClass::testAndSetRelaxed(_q_value, expectedValue, newValue);
     }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    bool testAndSetOrdered(T &_q_value, X expectedValue, X newValue) Q_DECL_NOTHROW
+    bool testAndSetOrdered(T &_q_value, X expectedValue, X newValue) noexcept
     {
         BaseClass::orderedMemoryFence(_q_value);
         return BaseClass::testAndSetRelaxed(_q_value, expectedValue, newValue);
     }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    bool testAndSetAcquire(T &_q_value, X expectedValue, X newValue, X *currentValue) Q_DECL_NOTHROW
+    bool testAndSetAcquire(T &_q_value, X expectedValue, X newValue, X *currentValue) noexcept
     {
         bool tmp = BaseClass::testAndSetRelaxed(_q_value, expectedValue, newValue, currentValue);
         BaseClass::acquireMemoryFence(_q_value);
@@ -169,24 +169,24 @@ template <typename BaseClass> struct QGenericAtomicOps
     }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    bool testAndSetRelease(T &_q_value, X expectedValue, X newValue, X *currentValue) Q_DECL_NOTHROW
+    bool testAndSetRelease(T &_q_value, X expectedValue, X newValue, X *currentValue) noexcept
     {
         BaseClass::releaseMemoryFence(_q_value);
         return BaseClass::testAndSetRelaxed(_q_value, expectedValue, newValue, currentValue);
     }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    bool testAndSetOrdered(T &_q_value, X expectedValue, X newValue, X *currentValue) Q_DECL_NOTHROW
+    bool testAndSetOrdered(T &_q_value, X expectedValue, X newValue, X *currentValue) noexcept
     {
         BaseClass::orderedMemoryFence(_q_value);
         return BaseClass::testAndSetRelaxed(_q_value, expectedValue, newValue, currentValue);
     }
 
-    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreNative() Q_DECL_NOTHROW { return false; }
-    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() Q_DECL_NOTHROW { return false; }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreNative() noexcept { return false; }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndStoreWaitFree() noexcept { return false; }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    T fetchAndStoreRelaxed(T &_q_value, X newValue) Q_DECL_NOTHROW
+    T fetchAndStoreRelaxed(T &_q_value, X newValue) noexcept
     {
         // implement fetchAndStore on top of testAndSet
         Q_FOREVER {
@@ -197,7 +197,7 @@ template <typename BaseClass> struct QGenericAtomicOps
     }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    T fetchAndStoreAcquire(T &_q_value, X newValue) Q_DECL_NOTHROW
+    T fetchAndStoreAcquire(T &_q_value, X newValue) noexcept
     {
         T tmp = BaseClass::fetchAndStoreRelaxed(_q_value, newValue);
         BaseClass::acquireMemoryFence(_q_value);
@@ -205,23 +205,23 @@ template <typename BaseClass> struct QGenericAtomicOps
     }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    T fetchAndStoreRelease(T &_q_value, X newValue) Q_DECL_NOTHROW
+    T fetchAndStoreRelease(T &_q_value, X newValue) noexcept
     {
         BaseClass::releaseMemoryFence(_q_value);
         return BaseClass::fetchAndStoreRelaxed(_q_value, newValue);
     }
 
     template <typename T, typename X> static Q_ALWAYS_INLINE
-    T fetchAndStoreOrdered(T &_q_value, X newValue) Q_DECL_NOTHROW
+    T fetchAndStoreOrdered(T &_q_value, X newValue) noexcept
     {
         BaseClass::orderedMemoryFence(_q_value);
         return BaseClass::fetchAndStoreRelaxed(_q_value, newValue);
     }
 
-    static inline Q_DECL_CONSTEXPR bool isFetchAndAddNative() Q_DECL_NOTHROW { return false; }
-    static inline Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() Q_DECL_NOTHROW { return false; }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndAddNative() noexcept { return false; }
+    static inline Q_DECL_CONSTEXPR bool isFetchAndAddWaitFree() noexcept { return false; }
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndAddRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         // implement fetchAndAdd on top of testAndSet
         Q_FOREVER {
@@ -232,7 +232,7 @@ template <typename BaseClass> struct QGenericAtomicOps
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndAddAcquire(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddAcquire(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         T tmp = BaseClass::fetchAndAddRelaxed(_q_value, valueToAdd);
         BaseClass::acquireMemoryFence(_q_value);
@@ -240,14 +240,14 @@ template <typename BaseClass> struct QGenericAtomicOps
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndAddRelease(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddRelease(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         BaseClass::releaseMemoryFence(_q_value);
         return BaseClass::fetchAndAddRelaxed(_q_value, valueToAdd);
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndAddOrdered(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) Q_DECL_NOTHROW
+    T fetchAndAddOrdered(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT valueToAdd) noexcept
     {
         BaseClass::orderedMemoryFence(_q_value);
         return BaseClass::fetchAndAddRelaxed(_q_value, valueToAdd);
@@ -256,7 +256,7 @@ template <typename BaseClass> struct QGenericAtomicOps
 QT_WARNING_PUSH
 QT_WARNING_DISABLE_MSVC(4146)   // unary minus operator applied to unsigned type, result still unsigned
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndSubRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT operand) Q_DECL_NOTHROW
+    T fetchAndSubRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT operand) noexcept
     {
         // implement fetchAndSub on top of fetchAndAdd
         return fetchAndAddRelaxed(_q_value, -operand);
@@ -264,7 +264,7 @@ QT_WARNING_DISABLE_MSVC(4146)   // unary minus operator applied to unsigned type
 QT_WARNING_POP
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndSubAcquire(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT operand) Q_DECL_NOTHROW
+    T fetchAndSubAcquire(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT operand) noexcept
     {
         T tmp = BaseClass::fetchAndSubRelaxed(_q_value, operand);
         BaseClass::acquireMemoryFence(_q_value);
@@ -272,21 +272,21 @@ QT_WARNING_POP
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndSubRelease(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT operand) Q_DECL_NOTHROW
+    T fetchAndSubRelease(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT operand) noexcept
     {
         BaseClass::releaseMemoryFence(_q_value);
         return BaseClass::fetchAndSubRelaxed(_q_value, operand);
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndSubOrdered(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT operand) Q_DECL_NOTHROW
+    T fetchAndSubOrdered(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT operand) noexcept
     {
         BaseClass::orderedMemoryFence(_q_value);
         return BaseClass::fetchAndSubRelaxed(_q_value, operand);
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndAndRelaxed(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndAndRelaxed(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         // implement fetchAndAnd on top of testAndSet
         T tmp = BaseClass::load(_q_value);
@@ -297,7 +297,7 @@ QT_WARNING_POP
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndAndAcquire(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndAndAcquire(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         T tmp = BaseClass::fetchAndAndRelaxed(_q_value, operand);
         BaseClass::acquireMemoryFence(_q_value);
@@ -305,21 +305,21 @@ QT_WARNING_POP
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndAndRelease(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndAndRelease(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         BaseClass::releaseMemoryFence(_q_value);
         return BaseClass::fetchAndAndRelaxed(_q_value, operand);
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndAndOrdered(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndAndOrdered(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         BaseClass::orderedMemoryFence(_q_value);
         return BaseClass::fetchAndAndRelaxed(_q_value, operand);
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndOrRelaxed(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndOrRelaxed(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         // implement fetchAndOr on top of testAndSet
         T tmp = BaseClass::load(_q_value);
@@ -330,7 +330,7 @@ QT_WARNING_POP
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndOrAcquire(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndOrAcquire(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         T tmp = BaseClass::fetchAndOrRelaxed(_q_value, operand);
         BaseClass::acquireMemoryFence(_q_value);
@@ -338,21 +338,21 @@ QT_WARNING_POP
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndOrRelease(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndOrRelease(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         BaseClass::releaseMemoryFence(_q_value);
         return BaseClass::fetchAndOrRelaxed(_q_value, operand);
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndOrOrdered(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndOrOrdered(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         BaseClass::orderedMemoryFence(_q_value);
         return BaseClass::fetchAndOrRelaxed(_q_value, operand);
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndXorRelaxed(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndXorRelaxed(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         // implement fetchAndXor on top of testAndSet
         T tmp = BaseClass::load(_q_value);
@@ -363,7 +363,7 @@ QT_WARNING_POP
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndXorAcquire(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndXorAcquire(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         T tmp = BaseClass::fetchAndXorRelaxed(_q_value, operand);
         BaseClass::acquireMemoryFence(_q_value);
@@ -371,14 +371,14 @@ QT_WARNING_POP
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndXorRelease(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndXorRelease(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         BaseClass::releaseMemoryFence(_q_value);
         return BaseClass::fetchAndXorRelaxed(_q_value, operand);
     }
 
     template <typename T> static Q_ALWAYS_INLINE
-    T fetchAndXorOrdered(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) Q_DECL_NOTHROW
+    T fetchAndXorOrdered(T &_q_value, typename std::enable_if<QTypeInfo<T>::isIntegral, T>::type operand) noexcept
     {
         BaseClass::orderedMemoryFence(_q_value);
         return BaseClass::fetchAndXorRelaxed(_q_value, operand);
diff --git a/src/corelib/thread/qmutex.cpp b/src/corelib/thread/qmutex.cpp
index 3881ac017e..4f55e50fe5 100644
--- a/src/corelib/thread/qmutex.cpp
+++ b/src/corelib/thread/qmutex.cpp
@@ -82,7 +82,7 @@ public:
     QMutex mutex;
 
     bool lock(int timeout) QT_MUTEX_LOCK_NOEXCEPT;
-    void unlock() Q_DECL_NOTHROW;
+    void unlock() noexcept;
 };
 
 /*
@@ -329,7 +329,7 @@ bool QMutex::tryLock(int timeout) QT_MUTEX_LOCK_NOEXCEPT
 
     \sa lock()
 */
-void QMutex::unlock() Q_DECL_NOTHROW
+void QMutex::unlock() noexcept
 {
     QMutexData *current;
     if (fastTryUnlock(current))
@@ -348,7 +348,7 @@ void QMutex::unlock() Q_DECL_NOTHROW
     Returns \c true if the mutex is recursive.
 */
 
-bool QBasicMutex::isRecursive() Q_DECL_NOTHROW
+bool QBasicMutex::isRecursive() noexcept
 {
     return QT_PREPEND_NAMESPACE(isRecursive)(d_ptr.loadAcquire());
 }
@@ -358,7 +358,7 @@ bool QBasicMutex::isRecursive() Q_DECL_NOTHROW
 
     Returns \c true if the mutex is recursive.
 */
-bool QBasicMutex::isRecursive() const Q_DECL_NOTHROW
+bool QBasicMutex::isRecursive() const noexcept
 {
     return QT_PREPEND_NAMESPACE(isRecursive)(d_ptr.loadAcquire());
 }
@@ -600,7 +600,7 @@ bool QBasicMutex::lockInternal(int timeout) QT_MUTEX_LOCK_NOEXCEPT
 /*!
     \internal
 */
-void QBasicMutex::unlockInternal() Q_DECL_NOTHROW
+void QBasicMutex::unlockInternal() noexcept
 {
     QMutexData *copy = d_ptr.loadAcquire();
     Q_ASSERT(copy); //we must be locked
@@ -675,7 +675,7 @@ void QMutexPrivate::release()
 }
 
 // atomically subtract "value" to the waiters, and remove the QMutexPrivate::BigNumber flag
-void QMutexPrivate::derefWaiters(int value) Q_DECL_NOTHROW
+void QMutexPrivate::derefWaiters(int value) noexcept
 {
     int old_waiters;
     int new_waiters;
@@ -716,7 +716,7 @@ inline bool QRecursiveMutexPrivate::lock(int timeout) QT_MUTEX_LOCK_NOEXCEPT
 /*!
    \internal
  */
-inline void QRecursiveMutexPrivate::unlock() Q_DECL_NOTHROW
+inline void QRecursiveMutexPrivate::unlock() noexcept
 {
     if (count > 0) {
         count--;
diff --git a/src/corelib/thread/qmutex.h b/src/corelib/thread/qmutex.h
index 837355a602..d7796092d1 100644
--- a/src/corelib/thread/qmutex.h
+++ b/src/corelib/thread/qmutex.h
@@ -57,7 +57,7 @@ QT_BEGIN_NAMESPACE
 #if QT_CONFIG(thread) || defined(Q_CLANG_QDOC)
 
 #ifdef Q_OS_LINUX
-# define QT_MUTEX_LOCK_NOEXCEPT Q_DECL_NOTHROW
+# define QT_MUTEX_LOCK_NOEXCEPT noexcept
 #else
 # define QT_MUTEX_LOCK_NOEXCEPT
 #endif
@@ -80,39 +80,39 @@ public:
     }
 
     // BasicLockable concept
-    inline void unlock() Q_DECL_NOTHROW {
+    inline void unlock() noexcept {
         Q_ASSERT(d_ptr.load()); //mutex must be locked
         if (!fastTryUnlock())
             unlockInternal();
     }
 
-    bool tryLock() Q_DECL_NOTHROW {
+    bool tryLock() noexcept {
         return fastTryLock();
     }
 
     // Lockable concept
-    bool try_lock() Q_DECL_NOTHROW { return tryLock(); }
+    bool try_lock() noexcept { return tryLock(); }
 
-    bool isRecursive() Q_DECL_NOTHROW; //### Qt6: remove me
-    bool isRecursive() const Q_DECL_NOTHROW;
+    bool isRecursive() noexcept; //### Qt6: remove me
+    bool isRecursive() const noexcept;
 
 private:
-    inline bool fastTryLock() Q_DECL_NOTHROW {
+    inline bool fastTryLock() noexcept {
         return d_ptr.testAndSetAcquire(nullptr, dummyLocked());
     }
-    inline bool fastTryUnlock() Q_DECL_NOTHROW {
+    inline bool fastTryUnlock() noexcept {
         return d_ptr.testAndSetRelease(dummyLocked(), nullptr);
     }
-    inline bool fastTryLock(QMutexData *&current) Q_DECL_NOTHROW {
+    inline bool fastTryLock(QMutexData *&current) noexcept {
         return d_ptr.testAndSetAcquire(nullptr, dummyLocked(), current);
     }
-    inline bool fastTryUnlock(QMutexData *&current) Q_DECL_NOTHROW {
+    inline bool fastTryUnlock(QMutexData *&current) noexcept {
         return d_ptr.testAndSetRelease(dummyLocked(), nullptr, current);
     }
 
     void lockInternal() QT_MUTEX_LOCK_NOEXCEPT;
     bool lockInternal(int timeout) QT_MUTEX_LOCK_NOEXCEPT;
-    void unlockInternal() Q_DECL_NOTHROW;
+    void unlockInternal() noexcept;
 
     QBasicAtomicPointer<QMutexData> d_ptr;
     static inline QMutexData *dummyLocked() {
@@ -134,7 +134,7 @@ public:
     void lock() QT_MUTEX_LOCK_NOEXCEPT;
     bool tryLock(int timeout = 0) QT_MUTEX_LOCK_NOEXCEPT;
     // BasicLockable concept
-    void unlock() Q_DECL_NOTHROW;
+    void unlock() noexcept;
 
     // Lockable concept
     bool try_lock() QT_MUTEX_LOCK_NOEXCEPT { return tryLock(); }
@@ -158,7 +158,7 @@ public:
     }
 #endif
 
-    bool isRecursive() const Q_DECL_NOTHROW
+    bool isRecursive() const noexcept
     { return QBasicMutex::isRecursive(); }
 
 private:
@@ -212,7 +212,7 @@ public:
 #endif
     inline ~QMutexLocker() { unlock(); }
 
-    inline void unlock() Q_DECL_NOTHROW
+    inline void unlock() noexcept
     {
         if ((val & quintptr(1u)) == quintptr(1u)) {
             val &= ~quintptr(1u);
@@ -257,24 +257,24 @@ class Q_CORE_EXPORT QMutex
 public:
     enum RecursionMode { NonRecursive, Recursive };
 
-    inline Q_DECL_CONSTEXPR explicit QMutex(RecursionMode = NonRecursive) Q_DECL_NOTHROW { }
+    inline Q_DECL_CONSTEXPR explicit QMutex(RecursionMode = NonRecursive) noexcept { }
 
-    inline void lock() Q_DECL_NOTHROW {}
-    inline bool tryLock(int timeout = 0) Q_DECL_NOTHROW { Q_UNUSED(timeout); return true; }
-    inline bool try_lock() Q_DECL_NOTHROW { return true; }
-    inline void unlock() Q_DECL_NOTHROW {}
-    inline bool isRecursive() const Q_DECL_NOTHROW { return true; }
+    inline void lock() noexcept {}
+    inline bool tryLock(int timeout = 0) noexcept { Q_UNUSED(timeout); return true; }
+    inline bool try_lock() noexcept { return true; }
+    inline void unlock() noexcept {}
+    inline bool isRecursive() const noexcept { return true; }
 
 #if QT_HAS_INCLUDE(<chrono>)
     template <class Rep, class Period>
-    inline bool try_lock_for(std::chrono::duration<Rep, Period> duration) Q_DECL_NOTHROW
+    inline bool try_lock_for(std::chrono::duration<Rep, Period> duration) noexcept
     {
         Q_UNUSED(duration);
         return true;
     }
 
     template<class Clock, class Duration>
-    inline bool try_lock_until(std::chrono::time_point<Clock, Duration> timePoint) Q_DECL_NOTHROW
+    inline bool try_lock_until(std::chrono::time_point<Clock, Duration> timePoint) noexcept
     {
         Q_UNUSED(timePoint);
         return true;
@@ -288,12 +288,12 @@ private:
 class Q_CORE_EXPORT QMutexLocker
 {
 public:
-    inline explicit QMutexLocker(QMutex *) Q_DECL_NOTHROW {}
-    inline ~QMutexLocker() Q_DECL_NOTHROW {}
+    inline explicit QMutexLocker(QMutex *) noexcept {}
+    inline ~QMutexLocker() noexcept {}
 
-    inline void unlock() Q_DECL_NOTHROW {}
-    void relock() Q_DECL_NOTHROW {}
-    inline QMutex *mutex() const Q_DECL_NOTHROW { return nullptr; }
+    inline void unlock() noexcept {}
+    void relock() noexcept {}
+    inline QMutex *mutex() const noexcept { return nullptr; }
 
 private:
     Q_DISABLE_COPY(QMutexLocker)
diff --git a/src/corelib/thread/qmutex_linux.cpp b/src/corelib/thread/qmutex_linux.cpp
index 507e72cb76..b006ff1033 100644
--- a/src/corelib/thread/qmutex_linux.cpp
+++ b/src/corelib/thread/qmutex_linux.cpp
@@ -106,7 +106,7 @@ static inline QMutexData *dummyFutexValue()
 }
 
 template <bool IsTimed> static inline
-bool lockInternal_helper(QBasicAtomicPointer<QMutexData> &d_ptr, int timeout = -1, QElapsedTimer *elapsedTimer = 0) Q_DECL_NOTHROW
+bool lockInternal_helper(QBasicAtomicPointer<QMutexData> &d_ptr, int timeout = -1, QElapsedTimer *elapsedTimer = 0) noexcept
 {
     if (!IsTimed)
         timeout = -1;
@@ -153,13 +153,13 @@ bool lockInternal_helper(QBasicAtomicPointer<QMutexData> &d_ptr, int timeout = -
     return true;
 }
 
-void QBasicMutex::lockInternal() Q_DECL_NOTHROW
+void QBasicMutex::lockInternal() noexcept
 {
     Q_ASSERT(!isRecursive());
     lockInternal_helper<false>(d_ptr);
 }
 
-bool QBasicMutex::lockInternal(int timeout) Q_DECL_NOTHROW
+bool QBasicMutex::lockInternal(int timeout) noexcept
 {
     Q_ASSERT(!isRecursive());
     QElapsedTimer elapsedTimer;
@@ -167,7 +167,7 @@ bool QBasicMutex::lockInternal(int timeout) Q_DECL_NOTHROW
     return lockInternal_helper<true>(d_ptr, timeout, &elapsedTimer);
 }
 
-void QBasicMutex::unlockInternal() Q_DECL_NOTHROW
+void QBasicMutex::unlockInternal() noexcept
 {
     QMutexData *d = d_ptr.load();
     Q_ASSERT(d); //we must be locked
diff --git a/src/corelib/thread/qmutex_mac.cpp b/src/corelib/thread/qmutex_mac.cpp
index 9a8d9bc750..923f89f697 100644
--- a/src/corelib/thread/qmutex_mac.cpp
+++ b/src/corelib/thread/qmutex_mac.cpp
@@ -79,7 +79,7 @@ bool QMutexPrivate::wait(int timeout)
     return (r == KERN_SUCCESS);
 }
 
-void QMutexPrivate::wakeUp() Q_DECL_NOTHROW
+void QMutexPrivate::wakeUp() noexcept
 {
     semaphore_signal(mach_semaphore);
 }
diff --git a/src/corelib/thread/qmutex_p.h b/src/corelib/thread/qmutex_p.h
index ec9bfc1152..5025f836b9 100644
--- a/src/corelib/thread/qmutex_p.h
+++ b/src/corelib/thread/qmutex_p.h
@@ -92,7 +92,7 @@ public:
     QMutexPrivate();
 
     bool wait(int timeout = -1);
-    void wakeUp() Q_DECL_NOTHROW;
+    void wakeUp() noexcept;
 
     // Control the lifetime of the privates
     QAtomicInt refCount;
@@ -125,7 +125,7 @@ public:
                                     when the mutex is unlocked.
                                   */
     enum { BigNumber = 0x100000 }; //Must be bigger than the possible number of waiters (number of threads)
-    void derefWaiters(int value) Q_DECL_NOTHROW;
+    void derefWaiters(int value) noexcept;
 
     //platform specific stuff
 #if defined(Q_OS_MAC)
diff --git a/src/corelib/thread/qmutex_unix.cpp b/src/corelib/thread/qmutex_unix.cpp
index 3ee24a292c..a92ac4f943 100644
--- a/src/corelib/thread/qmutex_unix.cpp
+++ b/src/corelib/thread/qmutex_unix.cpp
@@ -99,7 +99,7 @@ bool QMutexPrivate::wait(int timeout)
     return true;
 }
 
-void QMutexPrivate::wakeUp() Q_DECL_NOTHROW
+void QMutexPrivate::wakeUp() noexcept
 {
     report_error(sem_post(&semaphore), "QMutex::unlock", "sem_post");
 }
@@ -146,7 +146,7 @@ bool QMutexPrivate::wait(int timeout)
     return ret;
 }
 
-void QMutexPrivate::wakeUp() Q_DECL_NOTHROW
+void QMutexPrivate::wakeUp() noexcept
 {
     report_error(pthread_mutex_lock(&mutex), "QMutex::unlock", "mutex lock");
     wakeup = true;
diff --git a/src/corelib/thread/qmutex_win.cpp b/src/corelib/thread/qmutex_win.cpp
index 3c314a4c0c..e221bc89cb 100644
--- a/src/corelib/thread/qmutex_win.cpp
+++ b/src/corelib/thread/qmutex_win.cpp
@@ -64,7 +64,7 @@ bool QMutexPrivate::wait(int timeout)
     return (WaitForSingleObjectEx(event, timeout < 0 ? INFINITE : timeout, FALSE) == WAIT_OBJECT_0);
 }
 
-void QMutexPrivate::wakeUp() Q_DECL_NOTHROW
+void QMutexPrivate::wakeUp() noexcept
 { SetEvent(event); }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/thread/qorderedmutexlocker_p.h b/src/corelib/thread/qorderedmutexlocker_p.h
index 5b2c7ab112..e0a67388d4 100644
--- a/src/corelib/thread/qorderedmutexlocker_p.h
+++ b/src/corelib/thread/qorderedmutexlocker_p.h
@@ -129,7 +129,7 @@ public:
     }
     inline ~QBasicMutexLocker() { if (isLocked) unlock(); }
 
-    inline void unlock() Q_DECL_NOTHROW
+    inline void unlock() noexcept
     {
         isLocked = false;
         m->unlock();
diff --git a/src/corelib/thread/qreadwritelock.h b/src/corelib/thread/qreadwritelock.h
index 65fa76fd6d..139fde9214 100644
--- a/src/corelib/thread/qreadwritelock.h
+++ b/src/corelib/thread/qreadwritelock.h
@@ -180,18 +180,18 @@ class Q_CORE_EXPORT QReadWriteLock
 {
 public:
     enum RecursionMode { NonRecursive, Recursive };
-    inline explicit QReadWriteLock(RecursionMode = NonRecursive) Q_DECL_NOTHROW { }
+    inline explicit QReadWriteLock(RecursionMode = NonRecursive) noexcept { }
     inline ~QReadWriteLock() { }
 
-    static inline void lockForRead() Q_DECL_NOTHROW { }
-    static inline bool tryLockForRead() Q_DECL_NOTHROW { return true; }
-    static inline bool tryLockForRead(int timeout) Q_DECL_NOTHROW { Q_UNUSED(timeout); return true; }
+    static inline void lockForRead() noexcept { }
+    static inline bool tryLockForRead() noexcept { return true; }
+    static inline bool tryLockForRead(int timeout) noexcept { Q_UNUSED(timeout); return true; }
 
-    static inline void lockForWrite() Q_DECL_NOTHROW { }
-    static inline bool tryLockForWrite() Q_DECL_NOTHROW { return true; }
-    static inline bool tryLockForWrite(int timeout) Q_DECL_NOTHROW { Q_UNUSED(timeout); return true; }
+    static inline void lockForWrite() noexcept { }
+    static inline bool tryLockForWrite() noexcept { return true; }
+    static inline bool tryLockForWrite(int timeout) noexcept { Q_UNUSED(timeout); return true; }
 
-    static inline void unlock() Q_DECL_NOTHROW { }
+    static inline void unlock() noexcept { }
 
 private:
     Q_DISABLE_COPY(QReadWriteLock)
@@ -200,12 +200,12 @@ private:
 class Q_CORE_EXPORT QReadLocker
 {
 public:
-    inline QReadLocker(QReadWriteLock *) Q_DECL_NOTHROW { }
-    inline ~QReadLocker() Q_DECL_NOTHROW { }
+    inline QReadLocker(QReadWriteLock *) noexcept { }
+    inline ~QReadLocker() noexcept { }
 
-    static inline void unlock() Q_DECL_NOTHROW { }
-    static inline void relock() Q_DECL_NOTHROW { }
-    static inline QReadWriteLock *readWriteLock() Q_DECL_NOTHROW { return nullptr; }
+    static inline void unlock() noexcept { }
+    static inline void relock() noexcept { }
+    static inline QReadWriteLock *readWriteLock() noexcept { return nullptr; }
 
 private:
     Q_DISABLE_COPY(QReadLocker)
@@ -214,12 +214,12 @@ private:
 class Q_CORE_EXPORT QWriteLocker
 {
 public:
-    inline explicit QWriteLocker(QReadWriteLock *) Q_DECL_NOTHROW { }
-    inline ~QWriteLocker() Q_DECL_NOTHROW { }
+    inline explicit QWriteLocker(QReadWriteLock *) noexcept { }
+    inline ~QWriteLocker() noexcept { }
 
-    static inline void unlock() Q_DECL_NOTHROW { }
-    static inline void relock() Q_DECL_NOTHROW { }
-    static inline QReadWriteLock *readWriteLock() Q_DECL_NOTHROW { return nullptr; }
+    static inline void unlock() noexcept { }
+    static inline void relock() noexcept { }
+    static inline QReadWriteLock *readWriteLock() noexcept { return nullptr; }
 
 private:
     Q_DISABLE_COPY(QWriteLocker)
diff --git a/src/corelib/thread/qsemaphore.h b/src/corelib/thread/qsemaphore.h
index b830ff1bfd..58c12997ad 100644
--- a/src/corelib/thread/qsemaphore.h
+++ b/src/corelib/thread/qsemaphore.h
@@ -75,14 +75,14 @@ class QSemaphoreReleaser
 {
 public:
     QSemaphoreReleaser() = default;
-    explicit QSemaphoreReleaser(QSemaphore &sem, int n = 1) Q_DECL_NOTHROW
+    explicit QSemaphoreReleaser(QSemaphore &sem, int n = 1) noexcept
         : m_sem(&sem), m_n(n) {}
-    explicit QSemaphoreReleaser(QSemaphore *sem, int n = 1) Q_DECL_NOTHROW
+    explicit QSemaphoreReleaser(QSemaphore *sem, int n = 1) noexcept
         : m_sem(sem), m_n(n) {}
-    QSemaphoreReleaser(QSemaphoreReleaser &&other) Q_DECL_NOTHROW
+    QSemaphoreReleaser(QSemaphoreReleaser &&other) noexcept
         : m_sem(other.m_sem), m_n(other.m_n)
     { other.m_sem = nullptr; }
-    QSemaphoreReleaser &operator=(QSemaphoreReleaser &&other) Q_DECL_NOTHROW
+    QSemaphoreReleaser &operator=(QSemaphoreReleaser &&other) noexcept
     { QSemaphoreReleaser moved(std::move(other)); swap(moved); return *this; }
 
     ~QSemaphoreReleaser()
@@ -91,16 +91,16 @@ public:
             m_sem->release(m_n);
     }
 
-    void swap(QSemaphoreReleaser &other) Q_DECL_NOTHROW
+    void swap(QSemaphoreReleaser &other) noexcept
     {
         qSwap(m_sem, other.m_sem);
         qSwap(m_n, other.m_n);
     }
 
-    QSemaphore *semaphore() const Q_DECL_NOTHROW
+    QSemaphore *semaphore() const noexcept
     { return m_sem; }
 
-    QSemaphore *cancel() Q_DECL_NOTHROW
+    QSemaphore *cancel() noexcept
     {
         QSemaphore *old = m_sem;
         m_sem = nullptr;
diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp
index b023ae9ed2..170cd0dec4 100644
--- a/src/corelib/thread/qthread.cpp
+++ b/src/corelib/thread/qthread.cpp
@@ -839,7 +839,7 @@ bool QThread::event(QEvent* event)
     return QObject::event(event);
 }
 
-Qt::HANDLE QThread::currentThreadId() Q_DECL_NOTHROW
+Qt::HANDLE QThread::currentThreadId() noexcept
 {
     return Qt::HANDLE(currentThread());
 }
@@ -849,7 +849,7 @@ QThread *QThread::currentThread()
     return QThreadData::current()->thread;
 }
 
-int QThread::idealThreadCount() Q_DECL_NOTHROW
+int QThread::idealThreadCount() noexcept
 {
     return 1;
 }
diff --git a/src/corelib/thread/qthread.h b/src/corelib/thread/qthread.h
index b6c5bf47d0..8e92d75401 100644
--- a/src/corelib/thread/qthread.h
+++ b/src/corelib/thread/qthread.h
@@ -70,9 +70,9 @@ class Q_CORE_EXPORT QThread : public QObject
 {
     Q_OBJECT
 public:
-    static Qt::HANDLE currentThreadId() Q_DECL_NOTHROW Q_DECL_PURE_FUNCTION;
+    static Qt::HANDLE currentThreadId() noexcept Q_DECL_PURE_FUNCTION;
     static QThread *currentThread();
-    static int idealThreadCount() Q_DECL_NOTHROW;
+    static int idealThreadCount() noexcept;
     static void yieldCurrentThread();
 
     explicit QThread(QObject *parent = nullptr);
diff --git a/src/corelib/thread/qthread_p.h b/src/corelib/thread/qthread_p.h
index e614ddd004..209225de98 100644
--- a/src/corelib/thread/qthread_p.h
+++ b/src/corelib/thread/qthread_p.h
@@ -187,8 +187,8 @@ public:
 #endif // Q_OS_UNIX
 
 #ifdef Q_OS_WIN
-    static unsigned int __stdcall start(void *) Q_DECL_NOEXCEPT;
-    static void finish(void *, bool lockAnyway=true) Q_DECL_NOEXCEPT;
+    static unsigned int __stdcall start(void *) noexcept;
+    static void finish(void *, bool lockAnyway=true) noexcept;
 
     Qt::HANDLE handle;
     unsigned int id;
diff --git a/src/corelib/thread/qthread_unix.cpp b/src/corelib/thread/qthread_unix.cpp
index a13f8ca215..8328e514a8 100644
--- a/src/corelib/thread/qthread_unix.cpp
+++ b/src/corelib/thread/qthread_unix.cpp
@@ -443,7 +443,7 @@ void QThreadPrivate::finish(void *arg)
  ** QThread
  *************************************************************************/
 
-Qt::HANDLE QThread::currentThreadId() Q_DECL_NOTHROW
+Qt::HANDLE QThread::currentThreadId() noexcept
 {
     // requires a C cast here otherwise we run into trouble on AIX
     return to_HANDLE(pthread_self());
@@ -454,7 +454,7 @@ Qt::HANDLE QThread::currentThreadId() Q_DECL_NOTHROW
 #  define _SC_NPROCESSORS_ONLN 84
 #endif
 
-int QThread::idealThreadCount() Q_DECL_NOTHROW
+int QThread::idealThreadCount() noexcept
 {
     int cores = 1;
 
diff --git a/src/corelib/thread/qthread_win.cpp b/src/corelib/thread/qthread_win.cpp
index e56fe2c6ae..ee73280707 100644
--- a/src/corelib/thread/qthread_win.cpp
+++ b/src/corelib/thread/qthread_win.cpp
@@ -372,7 +372,7 @@ QAbstractEventDispatcher *QThreadPrivate::createEventDispatcher(QThreadData *dat
 
 #if QT_CONFIG(thread)
 
-unsigned int __stdcall QT_ENSURE_STACK_ALIGNED_FOR_SSE QThreadPrivate::start(void *arg) Q_DECL_NOEXCEPT
+unsigned int __stdcall QT_ENSURE_STACK_ALIGNED_FOR_SSE QThreadPrivate::start(void *arg) noexcept
 {
     QThread *thr = reinterpret_cast<QThread *>(arg);
     QThreadData *data = QThreadData::get2(thr);
@@ -406,7 +406,7 @@ unsigned int __stdcall QT_ENSURE_STACK_ALIGNED_FOR_SSE QThreadPrivate::start(voi
     return 0;
 }
 
-void QThreadPrivate::finish(void *arg, bool lockAnyway) Q_DECL_NOEXCEPT
+void QThreadPrivate::finish(void *arg, bool lockAnyway) noexcept
 {
     QThread *thr = reinterpret_cast<QThread *>(arg);
     QThreadPrivate *d = thr->d_func();
@@ -447,12 +447,12 @@ void QThreadPrivate::finish(void *arg, bool lockAnyway) Q_DECL_NOEXCEPT
  ** QThread
  *************************************************************************/
 
-Qt::HANDLE QThread::currentThreadId() Q_DECL_NOTHROW
+Qt::HANDLE QThread::currentThreadId() noexcept
 {
     return reinterpret_cast<Qt::HANDLE>(quintptr(GetCurrentThreadId()));
 }
 
-int QThread::idealThreadCount() Q_DECL_NOTHROW
+int QThread::idealThreadCount() noexcept
 {
     SYSTEM_INFO sysinfo;
 #ifndef Q_OS_WINRT
diff --git a/src/corelib/tools/qalgorithms.h b/src/corelib/tools/qalgorithms.h
index 0146e22fa3..f1243b5c61 100644
--- a/src/corelib/tools/qalgorithms.h
+++ b/src/corelib/tools/qalgorithms.h
@@ -533,7 +533,7 @@ QT_DEPRECATED_X("Use std::binary_search") Q_OUTOFLINE_TEMPLATE RandomAccessItera
 #if defined QT_HAS_CONSTEXPR_BUILTINS
 #if defined(Q_CC_GNU) || defined(Q_CC_CLANG)
 #  define QT_HAS_BUILTIN_CTZS
-Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctzs(quint16 v) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctzs(quint16 v) noexcept
 {
 #  if QT_HAS_BUILTIN(__builtin_ctzs)
     return __builtin_ctzs(v);
@@ -542,7 +542,7 @@ Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctzs(quint16 v) Q_DECL_NOTHROW
 #  endif
 }
 #define QT_HAS_BUILTIN_CLZS
-Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clzs(quint16 v) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clzs(quint16 v) noexcept
 {
 #  if QT_HAS_BUILTIN(__builtin_clzs)
     return __builtin_clzs(v);
@@ -551,40 +551,40 @@ Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clzs(quint16 v) Q_DECL_NOTHROW
 #  endif
 }
 #define QT_HAS_BUILTIN_CTZ
-Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctz(quint32 v) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctz(quint32 v) noexcept
 {
     return __builtin_ctz(v);
 }
 #define QT_HAS_BUILTIN_CLZ
-Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clz(quint32 v) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clz(quint32 v) noexcept
 {
     return __builtin_clz(v);
 }
 #define QT_HAS_BUILTIN_CTZLL
-Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctzll(quint64 v) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_ctzll(quint64 v) noexcept
 {
     return __builtin_ctzll(v);
 }
 #define QT_HAS_BUILTIN_CLZLL
-Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clzll(quint64 v) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_clzll(quint64 v) noexcept
 {
     return __builtin_clzll(v);
 }
 #define QALGORITHMS_USE_BUILTIN_POPCOUNT
-Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_popcount(quint32 v) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_popcount(quint32 v) noexcept
 {
     return __builtin_popcount(v);
 }
-Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_popcount(quint8 v) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_popcount(quint8 v) noexcept
 {
     return __builtin_popcount(v);
 }
-Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_popcount(quint16 v) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_popcount(quint16 v) noexcept
 {
     return __builtin_popcount(v);
 }
 #define QALGORITHMS_USE_BUILTIN_POPCOUNTLL
-Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_popcountll(quint64 v) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR Q_ALWAYS_INLINE uint qt_builtin_popcountll(quint64 v) noexcept
 {
     return __builtin_popcountll(v);
 }
@@ -630,12 +630,12 @@ Q_ALWAYS_INLINE unsigned long qt_builtin_clzll(quint64 val)
 }
 #endif // MSVC 64bit
 #  define QT_HAS_BUILTIN_CTZS
-Q_ALWAYS_INLINE uint qt_builtin_ctzs(quint16 v) Q_DECL_NOTHROW
+Q_ALWAYS_INLINE uint qt_builtin_ctzs(quint16 v) noexcept
 {
     return qt_builtin_ctz(v);
 }
 #define QT_HAS_BUILTIN_CLZS
-Q_ALWAYS_INLINE uint qt_builtin_clzs(quint16 v) Q_DECL_NOTHROW
+Q_ALWAYS_INLINE uint qt_builtin_clzs(quint16 v) noexcept
 {
     return qt_builtin_clz(v) - 16U;
 }
@@ -652,19 +652,19 @@ Q_ALWAYS_INLINE uint qt_builtin_clzs(quint16 v) Q_DECL_NOTHROW
 #if defined(__AVX__) || defined(__SSE4_2__) || defined(__POPCNT__)
 #define QALGORITHMS_USE_BUILTIN_POPCOUNT
 #define QALGORITHMS_USE_BUILTIN_POPCOUNTLL
-Q_ALWAYS_INLINE uint qt_builtin_popcount(quint32 v) Q_DECL_NOTHROW
+Q_ALWAYS_INLINE uint qt_builtin_popcount(quint32 v) noexcept
 {
     return __popcnt(v);
 }
-Q_ALWAYS_INLINE uint qt_builtin_popcount(quint8 v) Q_DECL_NOTHROW
+Q_ALWAYS_INLINE uint qt_builtin_popcount(quint8 v) noexcept
 {
     return __popcnt16(v);
 }
-Q_ALWAYS_INLINE uint qt_builtin_popcount(quint16 v) Q_DECL_NOTHROW
+Q_ALWAYS_INLINE uint qt_builtin_popcount(quint16 v) noexcept
 {
     return __popcnt16(v);
 }
-Q_ALWAYS_INLINE uint qt_builtin_popcountll(quint64 v) Q_DECL_NOTHROW
+Q_ALWAYS_INLINE uint qt_builtin_popcountll(quint64 v) noexcept
 {
 #if Q_PROCESSOR_WORDSIZE == 8
     return __popcnt64(v);
@@ -685,7 +685,7 @@ Q_ALWAYS_INLINE uint qt_builtin_popcountll(quint64 v) Q_DECL_NOTHROW
 
 } //namespace QAlgorithmsPrivate
 
-Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint32 v) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint32 v) noexcept
 {
 #ifdef QALGORITHMS_USE_BUILTIN_POPCOUNT
     return QAlgorithmsPrivate::qt_builtin_popcount(v);
@@ -698,7 +698,7 @@ Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint32
 #endif
 }
 
-Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint8 v) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint8 v) noexcept
 {
 #ifdef QALGORITHMS_USE_BUILTIN_POPCOUNT
     return QAlgorithmsPrivate::qt_builtin_popcount(v);
@@ -708,7 +708,7 @@ Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint8
 #endif
 }
 
-Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint16 v) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint16 v) noexcept
 {
 #ifdef QALGORITHMS_USE_BUILTIN_POPCOUNT
     return QAlgorithmsPrivate::qt_builtin_popcount(v);
@@ -719,7 +719,7 @@ Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint16
 #endif
 }
 
-Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint64 v) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint64 v) noexcept
 {
 #ifdef QALGORITHMS_USE_BUILTIN_POPCOUNTLL
     return QAlgorithmsPrivate::qt_builtin_popcountll(v);
@@ -734,7 +734,7 @@ Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(quint64
 #endif
 }
 
-Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(long unsigned int v) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(long unsigned int v) noexcept
 {
     return qPopulationCount(static_cast<quint64>(v));
 }
@@ -744,7 +744,7 @@ Q_DECL_CONST_FUNCTION QT_POPCOUNT_CONSTEXPR inline uint qPopulationCount(long un
 #endif
 #undef QT_POPCOUNT_CONSTEXPR
 
-Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint32 v) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint32 v) noexcept
 {
 #if defined(QT_HAS_BUILTIN_CTZ)
     return v ? QAlgorithmsPrivate::qt_builtin_ctz(v) : 32U;
@@ -762,7 +762,7 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint32 v) Q_DECL_NO
 #endif
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint8 v) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint8 v) noexcept
 {
 #if defined(QT_HAS_BUILTIN_CTZ)
     return v ? QAlgorithmsPrivate::qt_builtin_ctz(v) : 8U;
@@ -777,7 +777,7 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint8 v) Q_DECL_NOT
 #endif
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint16 v) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint16 v) noexcept
 {
 #if defined(QT_HAS_BUILTIN_CTZS)
     return v ? QAlgorithmsPrivate::qt_builtin_ctzs(v) : 16U;
@@ -793,7 +793,7 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint16 v) Q_DECL_NO
 #endif
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint64 v) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint64 v) noexcept
 {
 #if defined(QT_HAS_BUILTIN_CTZLL)
     return v ? QAlgorithmsPrivate::qt_builtin_ctzll(v) : 64;
@@ -804,12 +804,12 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(quint64 v) Q_DECL_NO
 #endif
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(unsigned long v) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline uint qCountTrailingZeroBits(unsigned long v) noexcept
 {
     return qCountTrailingZeroBits(QIntegerForSizeof<long>::Unsigned(v));
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint32 v) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint32 v) noexcept
 {
 #if defined(QT_HAS_BUILTIN_CLZ)
     return v ? QAlgorithmsPrivate::qt_builtin_clz(v) : 32U;
@@ -824,7 +824,7 @@ Q_DECL_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint32 v) Q_DECL_NOT
 #endif
 }
 
-QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint8 v) Q_DECL_NOTHROW
+QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint8 v) noexcept
 {
 #if defined(QT_HAS_BUILTIN_CLZ)
     return v ? QAlgorithmsPrivate::qt_builtin_clz(v)-24U : 8U;
@@ -836,7 +836,7 @@ QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint8 v) Q_DECL
 #endif
 }
 
-QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint16 v) Q_DECL_NOTHROW
+QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint16 v) noexcept
 {
 #if defined(QT_HAS_BUILTIN_CLZS)
     return v ? QAlgorithmsPrivate::qt_builtin_clzs(v) : 16U;
@@ -849,7 +849,7 @@ QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint16 v) Q_DEC
 #endif
 }
 
-QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint64 v) Q_DECL_NOTHROW
+QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint64 v) noexcept
 {
 #if defined(QT_HAS_BUILTIN_CLZLL)
     return v ? QAlgorithmsPrivate::qt_builtin_clzll(v) : 64U;
@@ -864,7 +864,7 @@ QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(quint64 v) Q_DEC
 #endif
 }
 
-QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(unsigned long v) Q_DECL_NOTHROW
+QT_POPCOUNT_RELAXED_CONSTEXPR inline uint qCountLeadingZeroBits(unsigned long v) noexcept
 {
     return qCountLeadingZeroBits(QIntegerForSizeof<long>::Unsigned(v));
 }
diff --git a/src/corelib/tools/qarraydata.cpp b/src/corelib/tools/qarraydata.cpp
index a91d833e3b..bcc0688a91 100644
--- a/src/corelib/tools/qarraydata.cpp
+++ b/src/corelib/tools/qarraydata.cpp
@@ -87,7 +87,7 @@ static QArrayData *reallocateData(QArrayData *header, size_t allocSize, uint opt
 }
 
 QArrayData *QArrayData::allocate(size_t objectSize, size_t alignment,
-        size_t capacity, AllocationOptions options) Q_DECL_NOTHROW
+        size_t capacity, AllocationOptions options) noexcept
 {
     // Alignment is a power of two
     Q_ASSERT(alignment >= Q_ALIGNOF(QArrayData)
@@ -135,7 +135,7 @@ QArrayData *QArrayData::allocate(size_t objectSize, size_t alignment,
 }
 
 QArrayData *QArrayData::reallocateUnaligned(QArrayData *data, size_t objectSize, size_t capacity,
-                                            AllocationOptions options) Q_DECL_NOTHROW
+                                            AllocationOptions options) noexcept
 {
     Q_ASSERT(data);
     Q_ASSERT(data->isMutable());
@@ -150,7 +150,7 @@ QArrayData *QArrayData::reallocateUnaligned(QArrayData *data, size_t objectSize,
 }
 
 void QArrayData::deallocate(QArrayData *data, size_t objectSize,
-        size_t alignment) Q_DECL_NOTHROW
+        size_t alignment) noexcept
 {
     // Alignment is a power of two
     Q_ASSERT(alignment >= Q_ALIGNOF(QArrayData)
diff --git a/src/corelib/tools/qarraydata.h b/src/corelib/tools/qarraydata.h
index a642fb9b39..f78b9be2db 100644
--- a/src/corelib/tools/qarraydata.h
+++ b/src/corelib/tools/qarraydata.h
@@ -113,14 +113,14 @@ struct Q_CORE_EXPORT QArrayData
     }
 
     Q_REQUIRED_RESULT static QArrayData *allocate(size_t objectSize, size_t alignment,
-            size_t capacity, AllocationOptions options = Default) Q_DECL_NOTHROW;
+            size_t capacity, AllocationOptions options = Default) noexcept;
     Q_REQUIRED_RESULT static QArrayData *reallocateUnaligned(QArrayData *data, size_t objectSize,
-            size_t newCapacity, AllocationOptions newOptions = Default) Q_DECL_NOTHROW;
+            size_t newCapacity, AllocationOptions newOptions = Default) noexcept;
     static void deallocate(QArrayData *data, size_t objectSize,
-            size_t alignment) Q_DECL_NOTHROW;
+            size_t alignment) noexcept;
 
     static const QArrayData shared_null[2];
-    static QArrayData *sharedNull() Q_DECL_NOTHROW { return const_cast<QArrayData*>(shared_null); }
+    static QArrayData *sharedNull() noexcept { return const_cast<QArrayData*>(shared_null); }
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QArrayData::AllocationOptions)
@@ -254,7 +254,7 @@ struct QTypedArrayData
         return result;
     }
 
-    static QTypedArrayData *sharedNull() Q_DECL_NOTHROW
+    static QTypedArrayData *sharedNull() noexcept
     {
         Q_STATIC_ASSERT(sizeof(QTypedArrayData) == sizeof(QArrayData));
         return static_cast<QTypedArrayData *>(QArrayData::sharedNull());
diff --git a/src/corelib/tools/qarraydatapointer.h b/src/corelib/tools/qarraydatapointer.h
index 51cfa6e849..bce8fc8ddc 100644
--- a/src/corelib/tools/qarraydatapointer.h
+++ b/src/corelib/tools/qarraydatapointer.h
@@ -52,7 +52,7 @@ private:
     typedef QArrayDataOps<T> DataOps;
 
 public:
-    QArrayDataPointer() Q_DECL_NOTHROW
+    QArrayDataPointer() noexcept
         : d(Data::sharedNull())
     {
     }
@@ -83,13 +83,13 @@ public:
     }
 
 #ifdef Q_COMPILER_RVALUE_REFS
-    QArrayDataPointer(QArrayDataPointer &&other) Q_DECL_NOTHROW
+    QArrayDataPointer(QArrayDataPointer &&other) noexcept
         : d(other.d)
     {
         other.d = Data::sharedNull();
     }
 
-    QArrayDataPointer &operator=(QArrayDataPointer &&other) Q_DECL_NOTHROW
+    QArrayDataPointer &operator=(QArrayDataPointer &&other) noexcept
     {
         QArrayDataPointer moved(std::move(other));
         this->swap(moved);
@@ -150,7 +150,7 @@ public:
     bool isSharable() const { return d->isSharable(); }
 #endif
 
-    void swap(QArrayDataPointer &other) Q_DECL_NOTHROW
+    void swap(QArrayDataPointer &other) noexcept
     {
         qSwap(d, other.d);
     }
diff --git a/src/corelib/tools/qbitarray.h b/src/corelib/tools/qbitarray.h
index ff40bf5654..78beff0d42 100644
--- a/src/corelib/tools/qbitarray.h
+++ b/src/corelib/tools/qbitarray.h
@@ -50,21 +50,21 @@ class Q_CORE_EXPORT QBitArray
 {
     friend Q_CORE_EXPORT QDataStream &operator<<(QDataStream &, const QBitArray &);
     friend Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QBitArray &);
-    friend Q_CORE_EXPORT uint qHash(const QBitArray &key, uint seed) Q_DECL_NOTHROW;
+    friend Q_CORE_EXPORT uint qHash(const QBitArray &key, uint seed) noexcept;
     QByteArray d;
 
 public:
-    inline QBitArray() Q_DECL_NOTHROW {}
+    inline QBitArray() noexcept {}
     explicit QBitArray(int size, bool val = false);
     QBitArray(const QBitArray &other) : d(other.d) {}
     inline QBitArray &operator=(const QBitArray &other) { d = other.d; return *this; }
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QBitArray(QBitArray &&other) Q_DECL_NOTHROW : d(std::move(other.d)) {}
-    inline QBitArray &operator=(QBitArray &&other) Q_DECL_NOTHROW
+    inline QBitArray(QBitArray &&other) noexcept : d(std::move(other.d)) {}
+    inline QBitArray &operator=(QBitArray &&other) noexcept
     { qSwap(d, other.d); return *this; }
 #endif
 
-    inline void swap(QBitArray &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    inline void swap(QBitArray &other) noexcept { qSwap(d, other.d); }
 
     inline int size() const { return (d.size() << 3) - *d.constData(); }
     inline int count() const { return (d.size() << 3) - *d.constData(); }
diff --git a/src/corelib/tools/qbytearray.cpp b/src/corelib/tools/qbytearray.cpp
index 8bf20350d6..a5a473acf4 100644
--- a/src/corelib/tools/qbytearray.cpp
+++ b/src/corelib/tools/qbytearray.cpp
@@ -165,7 +165,7 @@ int qFindByteArray(
     This function returns SIZE_MAX (~0) on overflow or if the memory block size
     would not fit an int.
 */
-size_t qCalculateBlockSize(size_t elementCount, size_t elementSize, size_t headerSize) Q_DECL_NOTHROW
+size_t qCalculateBlockSize(size_t elementCount, size_t elementSize, size_t headerSize) noexcept
 {
     unsigned count = unsigned(elementCount);
     unsigned size = unsigned(elementSize);
@@ -206,7 +206,7 @@ size_t qCalculateBlockSize(size_t elementCount, size_t elementSize, size_t heade
     needed.
 */
 CalculateGrowingBlockSizeResult
-qCalculateGrowingBlockSize(size_t elementCount, size_t elementSize, size_t headerSize) Q_DECL_NOTHROW
+qCalculateGrowingBlockSize(size_t elementCount, size_t elementSize, size_t headerSize) noexcept
 {
     CalculateGrowingBlockSizeResult result = {
         std::numeric_limits<size_t>::max(),std::numeric_limits<size_t>::max()
@@ -1281,7 +1281,7 @@ QByteArray qUncompress(const uchar* data, int nbytes)
     Assigns \a other to this byte array and returns a reference to
     this byte array.
 */
-QByteArray &QByteArray::operator=(const QByteArray & other) Q_DECL_NOTHROW
+QByteArray &QByteArray::operator=(const QByteArray & other) noexcept
 {
     other.d->ref.ref();
     if (!d->ref.deref())
diff --git a/src/corelib/tools/qbytearray.h b/src/corelib/tools/qbytearray.h
index 8ee3a29ecc..318d773eb6 100644
--- a/src/corelib/tools/qbytearray.h
+++ b/src/corelib/tools/qbytearray.h
@@ -168,22 +168,22 @@ public:
     };
     Q_DECLARE_FLAGS(Base64Options, Base64Option)
 
-    inline QByteArray() Q_DECL_NOTHROW;
+    inline QByteArray() noexcept;
     QByteArray(const char *, int size = -1);
     QByteArray(int size, char c);
     QByteArray(int size, Qt::Initialization);
-    inline QByteArray(const QByteArray &) Q_DECL_NOTHROW;
+    inline QByteArray(const QByteArray &) noexcept;
     inline ~QByteArray();
 
-    QByteArray &operator=(const QByteArray &) Q_DECL_NOTHROW;
+    QByteArray &operator=(const QByteArray &) noexcept;
     QByteArray &operator=(const char *str);
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QByteArray(QByteArray && other) Q_DECL_NOTHROW : d(other.d) { other.d = Data::sharedNull(); }
-    inline QByteArray &operator=(QByteArray &&other) Q_DECL_NOTHROW
+    inline QByteArray(QByteArray && other) noexcept : d(other.d) { other.d = Data::sharedNull(); }
+    inline QByteArray &operator=(QByteArray &&other) noexcept
     { qSwap(d, other.d); return *this; }
 #endif
 
-    inline void swap(QByteArray &other) Q_DECL_NOTHROW
+    inline void swap(QByteArray &other) noexcept
     { qSwap(d, other.d); }
 
     inline int size() const;
@@ -472,7 +472,7 @@ public:
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QByteArray::Base64Options)
 
-inline QByteArray::QByteArray() Q_DECL_NOTHROW : d(Data::sharedNull()) { }
+inline QByteArray::QByteArray() noexcept : d(Data::sharedNull()) { }
 inline QByteArray::~QByteArray() { if (!d->ref.deref()) Data::deallocate(d); }
 inline int QByteArray::size() const
 { return d->size; }
@@ -502,7 +502,7 @@ inline void QByteArray::detach()
 { if (d->ref.isShared() || (d->offset != sizeof(QByteArrayData))) reallocData(uint(d->size) + 1u, d->detachFlags()); }
 inline bool QByteArray::isDetached() const
 { return !d->ref.isShared(); }
-inline QByteArray::QByteArray(const QByteArray &a) Q_DECL_NOTHROW : d(a.d)
+inline QByteArray::QByteArray(const QByteArray &a) noexcept : d(a.d)
 { d->ref.ref(); }
 
 inline int QByteArray::capacity() const
@@ -617,41 +617,41 @@ inline int QByteArray::compare(const QByteArray &a, Qt::CaseSensitivity cs) cons
     return cs == Qt::CaseSensitive ? qstrcmp(*this, a) :
                                      qstrnicmp(data(), size(), a.data(), a.size());
 }
-inline bool operator==(const QByteArray &a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator==(const QByteArray &a1, const QByteArray &a2) noexcept
 { return (a1.size() == a2.size()) && (memcmp(a1.constData(), a2.constData(), a1.size())==0); }
-inline bool operator==(const QByteArray &a1, const char *a2) Q_DECL_NOTHROW
+inline bool operator==(const QByteArray &a1, const char *a2) noexcept
 { return a2 ? qstrcmp(a1,a2) == 0 : a1.isEmpty(); }
-inline bool operator==(const char *a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator==(const char *a1, const QByteArray &a2) noexcept
 { return a1 ? qstrcmp(a1,a2) == 0 : a2.isEmpty(); }
-inline bool operator!=(const QByteArray &a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator!=(const QByteArray &a1, const QByteArray &a2) noexcept
 { return !(a1==a2); }
-inline bool operator!=(const QByteArray &a1, const char *a2) Q_DECL_NOTHROW
+inline bool operator!=(const QByteArray &a1, const char *a2) noexcept
 { return a2 ? qstrcmp(a1,a2) != 0 : !a1.isEmpty(); }
-inline bool operator!=(const char *a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator!=(const char *a1, const QByteArray &a2) noexcept
 { return a1 ? qstrcmp(a1,a2) != 0 : !a2.isEmpty(); }
-inline bool operator<(const QByteArray &a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator<(const QByteArray &a1, const QByteArray &a2) noexcept
 { return qstrcmp(a1, a2) < 0; }
- inline bool operator<(const QByteArray &a1, const char *a2) Q_DECL_NOTHROW
+ inline bool operator<(const QByteArray &a1, const char *a2) noexcept
 { return qstrcmp(a1, a2) < 0; }
-inline bool operator<(const char *a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator<(const char *a1, const QByteArray &a2) noexcept
 { return qstrcmp(a1, a2) < 0; }
-inline bool operator<=(const QByteArray &a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator<=(const QByteArray &a1, const QByteArray &a2) noexcept
 { return qstrcmp(a1, a2) <= 0; }
-inline bool operator<=(const QByteArray &a1, const char *a2) Q_DECL_NOTHROW
+inline bool operator<=(const QByteArray &a1, const char *a2) noexcept
 { return qstrcmp(a1, a2) <= 0; }
-inline bool operator<=(const char *a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator<=(const char *a1, const QByteArray &a2) noexcept
 { return qstrcmp(a1, a2) <= 0; }
-inline bool operator>(const QByteArray &a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator>(const QByteArray &a1, const QByteArray &a2) noexcept
 { return qstrcmp(a1, a2) > 0; }
-inline bool operator>(const QByteArray &a1, const char *a2) Q_DECL_NOTHROW
+inline bool operator>(const QByteArray &a1, const char *a2) noexcept
 { return qstrcmp(a1, a2) > 0; }
-inline bool operator>(const char *a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator>(const char *a1, const QByteArray &a2) noexcept
 { return qstrcmp(a1, a2) > 0; }
-inline bool operator>=(const QByteArray &a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator>=(const QByteArray &a1, const QByteArray &a2) noexcept
 { return qstrcmp(a1, a2) >= 0; }
-inline bool operator>=(const QByteArray &a1, const char *a2) Q_DECL_NOTHROW
+inline bool operator>=(const QByteArray &a1, const char *a2) noexcept
 { return qstrcmp(a1, a2) >= 0; }
-inline bool operator>=(const char *a1, const QByteArray &a2) Q_DECL_NOTHROW
+inline bool operator>=(const char *a1, const QByteArray &a2) noexcept
 { return qstrcmp(a1, a2) >= 0; }
 #if !defined(QT_USE_QSTRINGBUILDER)
 inline const QByteArray operator+(const QByteArray &a1, const QByteArray &a2)
diff --git a/src/corelib/tools/qbytearraymatcher.cpp b/src/corelib/tools/qbytearraymatcher.cpp
index 72f0e0519d..d2eb4e0e3c 100644
--- a/src/corelib/tools/qbytearraymatcher.cpp
+++ b/src/corelib/tools/qbytearraymatcher.cpp
@@ -404,7 +404,7 @@ int qFindByteArray(
 /*!
     \internal
 */
-int QStaticByteArrayMatcherBase::indexOfIn(const char *needle, uint nlen, const char *haystack, int hlen, int from) const Q_DECL_NOTHROW
+int QStaticByteArrayMatcherBase::indexOfIn(const char *needle, uint nlen, const char *haystack, int hlen, int from) const noexcept
 {
     if (from < 0)
         from = 0;
diff --git a/src/corelib/tools/qbytearraymatcher.h b/src/corelib/tools/qbytearraymatcher.h
index dafaea9c12..0eedfc1d20 100644
--- a/src/corelib/tools/qbytearraymatcher.h
+++ b/src/corelib/tools/qbytearraymatcher.h
@@ -90,15 +90,15 @@ class QStaticByteArrayMatcherBase
         uchar data[256];
     } m_skiptable;
 protected:
-    explicit Q_DECL_RELAXED_CONSTEXPR QStaticByteArrayMatcherBase(const char *pattern, uint n) Q_DECL_NOTHROW
+    explicit Q_DECL_RELAXED_CONSTEXPR QStaticByteArrayMatcherBase(const char *pattern, uint n) noexcept
         : m_skiptable(generate(pattern, n)) {}
     // compiler-generated copy/more ctors/assignment operators are ok!
     // compiler-generated dtor is ok!
 
-    Q_CORE_EXPORT int indexOfIn(const char *needle, uint nlen, const char *haystack, int hlen, int from) const Q_DECL_NOTHROW;
+    Q_CORE_EXPORT int indexOfIn(const char *needle, uint nlen, const char *haystack, int hlen, int from) const noexcept;
 
 private:
-    static Q_DECL_RELAXED_CONSTEXPR Skiptable generate(const char *pattern, uint n) Q_DECL_NOTHROW
+    static Q_DECL_RELAXED_CONSTEXPR Skiptable generate(const char *pattern, uint n) noexcept
     {
         const auto uchar_max = (std::numeric_limits<uchar>::max)();
         uchar max = n > uchar_max ? uchar_max : n;
@@ -140,23 +140,23 @@ class QStaticByteArrayMatcher : QStaticByteArrayMatcherBase
     char m_pattern[N];
     Q_STATIC_ASSERT_X(N > 2, "QStaticByteArrayMatcher makes no sense for finding a single-char pattern");
 public:
-    explicit Q_DECL_RELAXED_CONSTEXPR QStaticByteArrayMatcher(const char (&patternToMatch)[N]) Q_DECL_NOTHROW
+    explicit Q_DECL_RELAXED_CONSTEXPR QStaticByteArrayMatcher(const char (&patternToMatch)[N]) noexcept
         : QStaticByteArrayMatcherBase(patternToMatch, N - 1), m_pattern()
     {
         for (uint i = 0; i < N; ++i)
             m_pattern[i] = patternToMatch[i];
     }
 
-    int indexIn(const QByteArray &haystack, int from = 0) const Q_DECL_NOTHROW
+    int indexIn(const QByteArray &haystack, int from = 0) const noexcept
     { return this->indexOfIn(m_pattern, N - 1, haystack.data(), haystack.size(), from); }
-    int indexIn(const char *haystack, int hlen, int from = 0) const Q_DECL_NOTHROW
+    int indexIn(const char *haystack, int hlen, int from = 0) const noexcept
     { return this->indexOfIn(m_pattern, N - 1, haystack, hlen, from); }
 
     QByteArray pattern() const { return QByteArray(m_pattern, int(N - 1)); }
 };
 
 template <uint N>
-Q_DECL_RELAXED_CONSTEXPR QStaticByteArrayMatcher<N> qMakeStaticByteArrayMatcher(const char (&pattern)[N]) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR QStaticByteArrayMatcher<N> qMakeStaticByteArrayMatcher(const char (&pattern)[N]) noexcept
 { return QStaticByteArrayMatcher<N>(pattern); }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/tools/qcache.h b/src/corelib/tools/qcache.h
index b558a8358d..4fcde46fbc 100644
--- a/src/corelib/tools/qcache.h
+++ b/src/corelib/tools/qcache.h
@@ -89,7 +89,7 @@ class QCache
     Q_DISABLE_COPY(QCache)
 
 public:
-    inline explicit QCache(int maxCost = 100) Q_DECL_NOTHROW;
+    inline explicit QCache(int maxCost = 100) noexcept;
     inline ~QCache() { clear(); }
 
     inline int maxCost() const { return mx; }
@@ -116,7 +116,7 @@ private:
 };
 
 template <class Key, class T>
-inline QCache<Key, T>::QCache(int amaxCost) Q_DECL_NOTHROW
+inline QCache<Key, T>::QCache(int amaxCost) noexcept
     : f(nullptr), l(nullptr), mx(amaxCost), total(0) {}
 
 template <class Key, class T>
diff --git a/src/corelib/tools/qchar.cpp b/src/corelib/tools/qchar.cpp
index 47c853084b..d6061defc3 100644
--- a/src/corelib/tools/qchar.cpp
+++ b/src/corelib/tools/qchar.cpp
@@ -733,7 +733,7 @@ QT_BEGIN_NAMESPACE
     Note that this gives no indication of whether the character is
     available in a particular font.
 */
-bool QChar::isPrint(uint ucs4) Q_DECL_NOTHROW
+bool QChar::isPrint(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return false;
@@ -766,7 +766,7 @@ bool QChar::isPrint(uint ucs4) Q_DECL_NOTHROW
 /*!
     \internal
 */
-bool QT_FASTCALL QChar::isSpace_helper(uint ucs4) Q_DECL_NOTHROW
+bool QT_FASTCALL QChar::isSpace_helper(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return false;
@@ -792,7 +792,7 @@ bool QT_FASTCALL QChar::isSpace_helper(uint ucs4) Q_DECL_NOTHROW
     Returns \c true if the UCS-4-encoded character specified by \a ucs4 is
     a mark (Mark_* categories); otherwise returns \c false.
 */
-bool QChar::isMark(uint ucs4) Q_DECL_NOTHROW
+bool QChar::isMark(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return false;
@@ -816,7 +816,7 @@ bool QChar::isMark(uint ucs4) Q_DECL_NOTHROW
     Returns \c true if the UCS-4-encoded character specified by \a ucs4 is
     a punctuation mark (Punctuation_* categories); otherwise returns \c false.
 */
-bool QChar::isPunct(uint ucs4) Q_DECL_NOTHROW
+bool QChar::isPunct(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return false;
@@ -844,7 +844,7 @@ bool QChar::isPunct(uint ucs4) Q_DECL_NOTHROW
     Returns \c true if the UCS-4-encoded character specified by \a ucs4 is
     a symbol (Symbol_* categories); otherwise returns \c false.
 */
-bool QChar::isSymbol(uint ucs4) Q_DECL_NOTHROW
+bool QChar::isSymbol(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return false;
@@ -874,7 +874,7 @@ bool QChar::isSymbol(uint ucs4) Q_DECL_NOTHROW
 /*!
     \internal
 */
-bool QT_FASTCALL QChar::isLetter_helper(uint ucs4) Q_DECL_NOTHROW
+bool QT_FASTCALL QChar::isLetter_helper(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return false;
@@ -909,7 +909,7 @@ bool QT_FASTCALL QChar::isLetter_helper(uint ucs4) Q_DECL_NOTHROW
 /*!
     \internal
 */
-bool QT_FASTCALL QChar::isNumber_helper(uint ucs4) Q_DECL_NOTHROW
+bool QT_FASTCALL QChar::isNumber_helper(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return false;
@@ -938,7 +938,7 @@ bool QT_FASTCALL QChar::isNumber_helper(uint ucs4) Q_DECL_NOTHROW
 /*!
     \internal
 */
-bool QT_FASTCALL QChar::isLetterOrNumber_helper(uint ucs4) Q_DECL_NOTHROW
+bool QT_FASTCALL QChar::isLetterOrNumber_helper(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return false;
@@ -1101,7 +1101,7 @@ bool QT_FASTCALL QChar::isLetterOrNumber_helper(uint ucs4) Q_DECL_NOTHROW
     Returns the numeric value of the digit specified by the UCS-4-encoded
     character, \a ucs4, or -1 if the character is not a digit.
 */
-int QChar::digitValue(uint ucs4) Q_DECL_NOTHROW
+int QChar::digitValue(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return -1;
@@ -1118,7 +1118,7 @@ int QChar::digitValue(uint ucs4) Q_DECL_NOTHROW
     \overload
     Returns the category of the UCS-4-encoded character specified by \a ucs4.
 */
-QChar::Category QChar::category(uint ucs4) Q_DECL_NOTHROW
+QChar::Category QChar::category(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return QChar::Other_NotAssigned;
@@ -1135,7 +1135,7 @@ QChar::Category QChar::category(uint ucs4) Q_DECL_NOTHROW
     \overload
     Returns the direction of the UCS-4-encoded character specified by \a ucs4.
 */
-QChar::Direction QChar::direction(uint ucs4) Q_DECL_NOTHROW
+QChar::Direction QChar::direction(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return QChar::DirL;
@@ -1158,7 +1158,7 @@ QChar::Direction QChar::direction(uint ucs4) Q_DECL_NOTHROW
     character specified by \a ucs4
     (needed for certain languages such as Arabic or Syriac).
 */
-QChar::JoiningType QChar::joiningType(uint ucs4) Q_DECL_NOTHROW
+QChar::JoiningType QChar::joiningType(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return QChar::Joining_None;
@@ -1181,7 +1181,7 @@ QChar::JoiningType QChar::joiningType(uint ucs4) Q_DECL_NOTHROW
     Returns information about the joining properties of the UCS-4-encoded
     character specified by \a ucs4 (needed for certain languages such as Arabic).
 */
-QChar::Joining QChar::joining(uint ucs4) Q_DECL_NOTHROW
+QChar::Joining QChar::joining(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return QChar::OtherJoining;
@@ -1217,7 +1217,7 @@ QChar::Joining QChar::joining(uint ucs4) Q_DECL_NOTHROW
 
     \sa mirroredChar()
 */
-bool QChar::hasMirrored(uint ucs4) Q_DECL_NOTHROW
+bool QChar::hasMirrored(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return false;
@@ -1299,7 +1299,7 @@ bool QChar::hasMirrored(uint ucs4) Q_DECL_NOTHROW
 
     \sa hasMirrored()
 */
-uint QChar::mirroredChar(uint ucs4) Q_DECL_NOTHROW
+uint QChar::mirroredChar(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return ucs4;
@@ -1383,7 +1383,7 @@ QString QChar::decomposition(uint ucs4)
     Returns the tag defining the composition of the UCS-4-encoded character
     specified by \a ucs4. Returns QChar::NoDecomposition if no decomposition exists.
 */
-QChar::Decomposition QChar::decompositionTag(uint ucs4) Q_DECL_NOTHROW
+QChar::Decomposition QChar::decompositionTag(uint ucs4) noexcept
 {
     if (ucs4 >= Hangul_SBase && ucs4 < Hangul_SBase + Hangul_SCount)
         return QChar::Canonical;
@@ -1409,7 +1409,7 @@ QChar::Decomposition QChar::decompositionTag(uint ucs4) Q_DECL_NOTHROW
     Returns the combining class for the UCS-4-encoded character specified by
     \a ucs4, as defined in the Unicode standard.
 */
-unsigned char QChar::combiningClass(uint ucs4) Q_DECL_NOTHROW
+unsigned char QChar::combiningClass(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return 0;
@@ -1430,7 +1430,7 @@ unsigned char QChar::combiningClass(uint ucs4) Q_DECL_NOTHROW
     Returns the Unicode script property value for the character specified in
     its UCS-4-encoded form as \a ucs4.
 */
-QChar::Script QChar::script(uint ucs4) Q_DECL_NOTHROW
+QChar::Script QChar::script(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return QChar::Script_Unknown;
@@ -1448,7 +1448,7 @@ QChar::Script QChar::script(uint ucs4) Q_DECL_NOTHROW
     Returns the Unicode version that introduced the character specified in
     its UCS-4-encoded form as \a ucs4.
 */
-QChar::UnicodeVersion QChar::unicodeVersion(uint ucs4) Q_DECL_NOTHROW
+QChar::UnicodeVersion QChar::unicodeVersion(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return QChar::Unicode_Unassigned;
@@ -1458,14 +1458,14 @@ QChar::UnicodeVersion QChar::unicodeVersion(uint ucs4) Q_DECL_NOTHROW
 /*!
     Returns the most recent supported Unicode version.
 */
-QChar::UnicodeVersion QChar::currentUnicodeVersion() Q_DECL_NOTHROW
+QChar::UnicodeVersion QChar::currentUnicodeVersion() noexcept
 {
     return UNICODE_DATA_VERSION;
 }
 
 
 template <typename Traits, typename T>
-Q_DECL_CONST_FUNCTION static inline T convertCase_helper(T uc) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION static inline T convertCase_helper(T uc) noexcept
 {
     const QUnicodeTables::Properties *prop = qGetProp(uc);
 
@@ -1491,7 +1491,7 @@ Q_DECL_CONST_FUNCTION static inline T convertCase_helper(T uc) Q_DECL_NOTHROW
     by \a ucs4 if the character is uppercase or titlecase; otherwise returns
     the character itself.
 */
-uint QChar::toLower(uint ucs4) Q_DECL_NOTHROW
+uint QChar::toLower(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return ucs4;
@@ -1511,7 +1511,7 @@ uint QChar::toLower(uint ucs4) Q_DECL_NOTHROW
     by \a ucs4 if the character is lowercase or titlecase; otherwise returns
     the character itself.
 */
-uint QChar::toUpper(uint ucs4) Q_DECL_NOTHROW
+uint QChar::toUpper(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return ucs4;
@@ -1531,7 +1531,7 @@ uint QChar::toUpper(uint ucs4) Q_DECL_NOTHROW
     by \a ucs4 if the character is lowercase or uppercase; otherwise returns
     the character itself.
 */
-uint QChar::toTitleCase(uint ucs4) Q_DECL_NOTHROW
+uint QChar::toTitleCase(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return ucs4;
@@ -1546,7 +1546,7 @@ static inline uint foldCase(const ushort *ch, const ushort *start)
     return convertCase_helper<QUnicodeTables::CasefoldTraits>(ucs4);
 }
 
-static inline uint foldCase(uint ch, uint &last) Q_DECL_NOTHROW
+static inline uint foldCase(uint ch, uint &last) noexcept
 {
     uint ucs4 = ch;
     if (QChar::isLowSurrogate(ucs4) && QChar::isHighSurrogate(last))
@@ -1555,12 +1555,12 @@ static inline uint foldCase(uint ch, uint &last) Q_DECL_NOTHROW
     return convertCase_helper<QUnicodeTables::CasefoldTraits>(ucs4);
 }
 
-static inline ushort foldCase(ushort ch) Q_DECL_NOTHROW
+static inline ushort foldCase(ushort ch) noexcept
 {
     return convertCase_helper<QUnicodeTables::CasefoldTraits>(ch);
 }
 
-static inline QChar foldCase(QChar ch) Q_DECL_NOTHROW
+static inline QChar foldCase(QChar ch) noexcept
 {
     return QChar(foldCase(ch.unicode()));
 }
@@ -1577,7 +1577,7 @@ static inline QChar foldCase(QChar ch) Q_DECL_NOTHROW
     Returns the case folded equivalent of the UCS-4-encoded character specified
     by \a ucs4. For most Unicode characters this is the same as toLower().
 */
-uint QChar::toCaseFolded(uint ucs4) Q_DECL_NOTHROW
+uint QChar::toCaseFolded(uint ucs4) noexcept
 {
     if (ucs4 > LastValidCodePoint)
         return ucs4;
diff --git a/src/corelib/tools/qchar.h b/src/corelib/tools/qchar.h
index 8590b91ba3..be344838ed 100644
--- a/src/corelib/tools/qchar.h
+++ b/src/corelib/tools/qchar.h
@@ -50,9 +50,9 @@ class QString;
 struct QLatin1Char
 {
 public:
-    Q_DECL_CONSTEXPR inline explicit QLatin1Char(char c) Q_DECL_NOTHROW : ch(c) {}
-    Q_DECL_CONSTEXPR inline char toLatin1() const Q_DECL_NOTHROW { return ch; }
-    Q_DECL_CONSTEXPR inline ushort unicode() const Q_DECL_NOTHROW { return ushort(uchar(ch)); }
+    Q_DECL_CONSTEXPR inline explicit QLatin1Char(char c) noexcept : ch(c) {}
+    Q_DECL_CONSTEXPR inline char toLatin1() const noexcept { return ch; }
+    Q_DECL_CONSTEXPR inline ushort unicode() const noexcept { return ushort(uchar(ch)); }
 
 private:
     char ch;
@@ -78,30 +78,30 @@ public:
         LastValidCodePoint = 0x10ffff
     };
 
-    Q_DECL_CONSTEXPR QChar() Q_DECL_NOTHROW : ucs(0) {}
-    Q_DECL_CONSTEXPR QChar(ushort rc) Q_DECL_NOTHROW : ucs(rc) {} // implicit
-    Q_DECL_CONSTEXPR QChar(uchar c, uchar r) Q_DECL_NOTHROW : ucs(ushort((r << 8) | c)) {}
-    Q_DECL_CONSTEXPR QChar(short rc) Q_DECL_NOTHROW : ucs(ushort(rc)) {} // implicit
-    Q_DECL_CONSTEXPR QChar(uint rc) Q_DECL_NOTHROW : ucs(ushort(rc & 0xffff)) {}
-    Q_DECL_CONSTEXPR QChar(int rc) Q_DECL_NOTHROW : ucs(ushort(rc & 0xffff)) {}
-    Q_DECL_CONSTEXPR QChar(SpecialCharacter s) Q_DECL_NOTHROW : ucs(ushort(s)) {} // implicit
-    Q_DECL_CONSTEXPR QChar(QLatin1Char ch) Q_DECL_NOTHROW : ucs(ch.unicode()) {} // implicit
+    Q_DECL_CONSTEXPR QChar() noexcept : ucs(0) {}
+    Q_DECL_CONSTEXPR QChar(ushort rc) noexcept : ucs(rc) {} // implicit
+    Q_DECL_CONSTEXPR QChar(uchar c, uchar r) noexcept : ucs(ushort((r << 8) | c)) {}
+    Q_DECL_CONSTEXPR QChar(short rc) noexcept : ucs(ushort(rc)) {} // implicit
+    Q_DECL_CONSTEXPR QChar(uint rc) noexcept : ucs(ushort(rc & 0xffff)) {}
+    Q_DECL_CONSTEXPR QChar(int rc) noexcept : ucs(ushort(rc & 0xffff)) {}
+    Q_DECL_CONSTEXPR QChar(SpecialCharacter s) noexcept : ucs(ushort(s)) {} // implicit
+    Q_DECL_CONSTEXPR QChar(QLatin1Char ch) noexcept : ucs(ch.unicode()) {} // implicit
 #if defined(Q_COMPILER_UNICODE_STRINGS)
-    Q_DECL_CONSTEXPR QChar(char16_t ch) Q_DECL_NOTHROW : ucs(ushort(ch)) {} // implicit
+    Q_DECL_CONSTEXPR QChar(char16_t ch) noexcept : ucs(ushort(ch)) {} // implicit
 #endif
 #if defined(Q_OS_WIN)
     Q_STATIC_ASSERT(sizeof(wchar_t) == sizeof(ushort));
 #endif
 #if defined(Q_OS_WIN) || defined(Q_CLANG_QDOC)
 #   if !defined(_WCHAR_T_DEFINED) || defined(_NATIVE_WCHAR_T_DEFINED)
-    Q_DECL_CONSTEXPR QChar(wchar_t ch) Q_DECL_NOTHROW : ucs(ushort(ch)) {} // implicit
+    Q_DECL_CONSTEXPR QChar(wchar_t ch) noexcept : ucs(ushort(ch)) {} // implicit
 #   endif
 #endif
 
 #ifndef QT_NO_CAST_FROM_ASCII
-    QT_ASCII_CAST_WARN Q_DECL_CONSTEXPR explicit QChar(char c) Q_DECL_NOTHROW : ucs(uchar(c)) { }
+    QT_ASCII_CAST_WARN Q_DECL_CONSTEXPR explicit QChar(char c) noexcept : ucs(uchar(c)) { }
 #ifndef QT_RESTRICTED_CAST_FROM_ASCII
-    QT_ASCII_CAST_WARN Q_DECL_CONSTEXPR explicit QChar(uchar c) Q_DECL_NOTHROW : ucs(c) { }
+    QT_ASCII_CAST_WARN Q_DECL_CONSTEXPR explicit QChar(uchar c) noexcept : ucs(c) { }
 #endif
 #endif
     // Unicode information
@@ -411,11 +411,11 @@ public:
     };
     // ****** WHEN ADDING FUNCTIONS, CONSIDER ADDING TO QCharRef TOO
 
-    inline Category category() const Q_DECL_NOTHROW { return QChar::category(ucs); }
-    inline Direction direction() const Q_DECL_NOTHROW { return QChar::direction(ucs); }
-    inline JoiningType joiningType() const Q_DECL_NOTHROW { return QChar::joiningType(ucs); }
+    inline Category category() const noexcept { return QChar::category(ucs); }
+    inline Direction direction() const noexcept { return QChar::direction(ucs); }
+    inline JoiningType joiningType() const noexcept { return QChar::joiningType(ucs); }
 #if QT_DEPRECATED_SINCE(5, 3)
-    QT_DEPRECATED inline Joining joining() const Q_DECL_NOTHROW
+    QT_DEPRECATED inline Joining joining() const noexcept
     {
         switch (QChar::joiningType(ucs)) {
         case QChar::Joining_Causing: return QChar::Center;
@@ -428,198 +428,198 @@ public:
         }
     }
 #endif
-    inline unsigned char combiningClass() const Q_DECL_NOTHROW { return QChar::combiningClass(ucs); }
+    inline unsigned char combiningClass() const noexcept { return QChar::combiningClass(ucs); }
 
-    inline QChar mirroredChar() const Q_DECL_NOTHROW { return QChar::mirroredChar(ucs); }
-    inline bool hasMirrored() const Q_DECL_NOTHROW { return QChar::hasMirrored(ucs); }
+    inline QChar mirroredChar() const noexcept { return QChar::mirroredChar(ucs); }
+    inline bool hasMirrored() const noexcept { return QChar::hasMirrored(ucs); }
 
     QString decomposition() const;
-    inline Decomposition decompositionTag() const Q_DECL_NOTHROW { return QChar::decompositionTag(ucs); }
+    inline Decomposition decompositionTag() const noexcept { return QChar::decompositionTag(ucs); }
 
-    inline int digitValue() const Q_DECL_NOTHROW { return QChar::digitValue(ucs); }
-    inline QChar toLower() const Q_DECL_NOTHROW { return QChar::toLower(ucs); }
-    inline QChar toUpper() const Q_DECL_NOTHROW { return QChar::toUpper(ucs); }
-    inline QChar toTitleCase() const Q_DECL_NOTHROW { return QChar::toTitleCase(ucs); }
-    inline QChar toCaseFolded() const Q_DECL_NOTHROW { return QChar::toCaseFolded(ucs); }
+    inline int digitValue() const noexcept { return QChar::digitValue(ucs); }
+    inline QChar toLower() const noexcept { return QChar::toLower(ucs); }
+    inline QChar toUpper() const noexcept { return QChar::toUpper(ucs); }
+    inline QChar toTitleCase() const noexcept { return QChar::toTitleCase(ucs); }
+    inline QChar toCaseFolded() const noexcept { return QChar::toCaseFolded(ucs); }
 
-    inline Script script() const Q_DECL_NOTHROW { return QChar::script(ucs); }
+    inline Script script() const noexcept { return QChar::script(ucs); }
 
-    inline UnicodeVersion unicodeVersion() const Q_DECL_NOTHROW { return QChar::unicodeVersion(ucs); }
+    inline UnicodeVersion unicodeVersion() const noexcept { return QChar::unicodeVersion(ucs); }
 
 #if QT_DEPRECATED_SINCE(5, 0)
-    QT_DEPRECATED Q_DECL_CONSTEXPR inline char toAscii() const Q_DECL_NOTHROW { return toLatin1(); }
+    QT_DEPRECATED Q_DECL_CONSTEXPR inline char toAscii() const noexcept { return toLatin1(); }
 #endif
-    Q_DECL_CONSTEXPR inline char toLatin1() const Q_DECL_NOTHROW { return ucs > 0xff ? '\0' : char(ucs); }
-    Q_DECL_CONSTEXPR inline ushort unicode() const Q_DECL_NOTHROW { return ucs; }
-    Q_DECL_RELAXED_CONSTEXPR inline ushort &unicode() Q_DECL_NOTHROW { return ucs; }
+    Q_DECL_CONSTEXPR inline char toLatin1() const noexcept { return ucs > 0xff ? '\0' : char(ucs); }
+    Q_DECL_CONSTEXPR inline ushort unicode() const noexcept { return ucs; }
+    Q_DECL_RELAXED_CONSTEXPR inline ushort &unicode() noexcept { return ucs; }
 
 #if QT_DEPRECATED_SINCE(5, 0)
-    QT_DEPRECATED static Q_DECL_CONSTEXPR inline QChar fromAscii(char c) Q_DECL_NOTHROW
+    QT_DEPRECATED static Q_DECL_CONSTEXPR inline QChar fromAscii(char c) noexcept
     { return fromLatin1(c); }
 #endif
-    static Q_DECL_CONSTEXPR inline QChar fromLatin1(char c) Q_DECL_NOTHROW { return QChar(ushort(uchar(c))); }
-
-    Q_DECL_CONSTEXPR inline bool isNull() const Q_DECL_NOTHROW { return ucs == 0; }
-
-    inline bool isPrint() const Q_DECL_NOTHROW { return QChar::isPrint(ucs); }
-    Q_DECL_CONSTEXPR inline bool isSpace() const Q_DECL_NOTHROW { return QChar::isSpace(ucs); }
-    inline bool isMark() const Q_DECL_NOTHROW { return QChar::isMark(ucs); }
-    inline bool isPunct() const Q_DECL_NOTHROW { return QChar::isPunct(ucs); }
-    inline bool isSymbol() const Q_DECL_NOTHROW { return QChar::isSymbol(ucs); }
-    Q_DECL_CONSTEXPR inline bool isLetter() const Q_DECL_NOTHROW { return QChar::isLetter(ucs); }
-    Q_DECL_CONSTEXPR inline bool isNumber() const Q_DECL_NOTHROW { return QChar::isNumber(ucs); }
-    Q_DECL_CONSTEXPR inline bool isLetterOrNumber() const Q_DECL_NOTHROW { return QChar::isLetterOrNumber(ucs); }
-    Q_DECL_CONSTEXPR inline bool isDigit() const Q_DECL_NOTHROW { return QChar::isDigit(ucs); }
-    Q_DECL_CONSTEXPR inline bool isLower() const Q_DECL_NOTHROW { return QChar::isLower(ucs); }
-    Q_DECL_CONSTEXPR inline bool isUpper() const Q_DECL_NOTHROW { return QChar::isUpper(ucs); }
-    Q_DECL_CONSTEXPR inline bool isTitleCase() const Q_DECL_NOTHROW { return QChar::isTitleCase(ucs); }
-
-    Q_DECL_CONSTEXPR inline bool isNonCharacter() const Q_DECL_NOTHROW { return QChar::isNonCharacter(ucs); }
-    Q_DECL_CONSTEXPR inline bool isHighSurrogate() const Q_DECL_NOTHROW { return QChar::isHighSurrogate(ucs); }
-    Q_DECL_CONSTEXPR inline bool isLowSurrogate() const Q_DECL_NOTHROW { return QChar::isLowSurrogate(ucs); }
-    Q_DECL_CONSTEXPR inline bool isSurrogate() const Q_DECL_NOTHROW { return QChar::isSurrogate(ucs); }
-
-    Q_DECL_CONSTEXPR inline uchar cell() const Q_DECL_NOTHROW { return uchar(ucs & 0xff); }
-    Q_DECL_CONSTEXPR inline uchar row() const Q_DECL_NOTHROW { return uchar((ucs>>8)&0xff); }
-    Q_DECL_RELAXED_CONSTEXPR inline void setCell(uchar acell) Q_DECL_NOTHROW { ucs = ushort((ucs & 0xff00) + acell); }
-    Q_DECL_RELAXED_CONSTEXPR inline void setRow(uchar arow) Q_DECL_NOTHROW { ucs = ushort((ushort(arow)<<8) + (ucs&0xff)); }
-
-    static Q_DECL_CONSTEXPR inline bool isNonCharacter(uint ucs4) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR inline QChar fromLatin1(char c) noexcept { return QChar(ushort(uchar(c))); }
+
+    Q_DECL_CONSTEXPR inline bool isNull() const noexcept { return ucs == 0; }
+
+    inline bool isPrint() const noexcept { return QChar::isPrint(ucs); }
+    Q_DECL_CONSTEXPR inline bool isSpace() const noexcept { return QChar::isSpace(ucs); }
+    inline bool isMark() const noexcept { return QChar::isMark(ucs); }
+    inline bool isPunct() const noexcept { return QChar::isPunct(ucs); }
+    inline bool isSymbol() const noexcept { return QChar::isSymbol(ucs); }
+    Q_DECL_CONSTEXPR inline bool isLetter() const noexcept { return QChar::isLetter(ucs); }
+    Q_DECL_CONSTEXPR inline bool isNumber() const noexcept { return QChar::isNumber(ucs); }
+    Q_DECL_CONSTEXPR inline bool isLetterOrNumber() const noexcept { return QChar::isLetterOrNumber(ucs); }
+    Q_DECL_CONSTEXPR inline bool isDigit() const noexcept { return QChar::isDigit(ucs); }
+    Q_DECL_CONSTEXPR inline bool isLower() const noexcept { return QChar::isLower(ucs); }
+    Q_DECL_CONSTEXPR inline bool isUpper() const noexcept { return QChar::isUpper(ucs); }
+    Q_DECL_CONSTEXPR inline bool isTitleCase() const noexcept { return QChar::isTitleCase(ucs); }
+
+    Q_DECL_CONSTEXPR inline bool isNonCharacter() const noexcept { return QChar::isNonCharacter(ucs); }
+    Q_DECL_CONSTEXPR inline bool isHighSurrogate() const noexcept { return QChar::isHighSurrogate(ucs); }
+    Q_DECL_CONSTEXPR inline bool isLowSurrogate() const noexcept { return QChar::isLowSurrogate(ucs); }
+    Q_DECL_CONSTEXPR inline bool isSurrogate() const noexcept { return QChar::isSurrogate(ucs); }
+
+    Q_DECL_CONSTEXPR inline uchar cell() const noexcept { return uchar(ucs & 0xff); }
+    Q_DECL_CONSTEXPR inline uchar row() const noexcept { return uchar((ucs>>8)&0xff); }
+    Q_DECL_RELAXED_CONSTEXPR inline void setCell(uchar acell) noexcept { ucs = ushort((ucs & 0xff00) + acell); }
+    Q_DECL_RELAXED_CONSTEXPR inline void setRow(uchar arow) noexcept { ucs = ushort((ushort(arow)<<8) + (ucs&0xff)); }
+
+    static Q_DECL_CONSTEXPR inline bool isNonCharacter(uint ucs4) noexcept
     {
         return ucs4 >= 0xfdd0 && (ucs4 <= 0xfdef || (ucs4 & 0xfffe) == 0xfffe);
     }
-    static Q_DECL_CONSTEXPR inline bool isHighSurrogate(uint ucs4) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR inline bool isHighSurrogate(uint ucs4) noexcept
     {
         return ((ucs4 & 0xfffffc00) == 0xd800);
     }
-    static Q_DECL_CONSTEXPR inline bool isLowSurrogate(uint ucs4) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR inline bool isLowSurrogate(uint ucs4) noexcept
     {
         return ((ucs4 & 0xfffffc00) == 0xdc00);
     }
-    static Q_DECL_CONSTEXPR inline bool isSurrogate(uint ucs4) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR inline bool isSurrogate(uint ucs4) noexcept
     {
         return (ucs4 - 0xd800u < 2048u);
     }
-    static Q_DECL_CONSTEXPR inline bool requiresSurrogates(uint ucs4) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR inline bool requiresSurrogates(uint ucs4) noexcept
     {
         return (ucs4 >= 0x10000);
     }
-    static Q_DECL_CONSTEXPR inline uint surrogateToUcs4(ushort high, ushort low) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR inline uint surrogateToUcs4(ushort high, ushort low) noexcept
     {
         return (uint(high)<<10) + low - 0x35fdc00;
     }
-    static Q_DECL_CONSTEXPR inline uint surrogateToUcs4(QChar high, QChar low) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR inline uint surrogateToUcs4(QChar high, QChar low) noexcept
     {
         return surrogateToUcs4(high.ucs, low.ucs);
     }
-    static Q_DECL_CONSTEXPR inline ushort highSurrogate(uint ucs4) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR inline ushort highSurrogate(uint ucs4) noexcept
     {
         return ushort((ucs4>>10) + 0xd7c0);
     }
-    static Q_DECL_CONSTEXPR inline ushort lowSurrogate(uint ucs4) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR inline ushort lowSurrogate(uint ucs4) noexcept
     {
         return ushort(ucs4%0x400 + 0xdc00);
     }
 
-    static Category QT_FASTCALL category(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static Direction QT_FASTCALL direction(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static JoiningType QT_FASTCALL joiningType(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static Category QT_FASTCALL category(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static Direction QT_FASTCALL direction(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static JoiningType QT_FASTCALL joiningType(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
 #if QT_DEPRECATED_SINCE(5, 3)
-    QT_DEPRECATED static Joining QT_FASTCALL joining(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    QT_DEPRECATED static Joining QT_FASTCALL joining(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
 #endif
-    static unsigned char QT_FASTCALL combiningClass(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static unsigned char QT_FASTCALL combiningClass(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
 
-    static uint QT_FASTCALL mirroredChar(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static bool QT_FASTCALL hasMirrored(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static uint QT_FASTCALL mirroredChar(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static bool QT_FASTCALL hasMirrored(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
 
     static QString QT_FASTCALL decomposition(uint ucs4);
-    static Decomposition QT_FASTCALL decompositionTag(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static Decomposition QT_FASTCALL decompositionTag(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
 
-    static int QT_FASTCALL digitValue(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static uint QT_FASTCALL toLower(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static uint QT_FASTCALL toUpper(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static uint QT_FASTCALL toTitleCase(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static uint QT_FASTCALL toCaseFolded(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static int QT_FASTCALL digitValue(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static uint QT_FASTCALL toLower(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static uint QT_FASTCALL toUpper(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static uint QT_FASTCALL toTitleCase(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static uint QT_FASTCALL toCaseFolded(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
 
-    static Script QT_FASTCALL script(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static Script QT_FASTCALL script(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
 
-    static UnicodeVersion QT_FASTCALL unicodeVersion(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static UnicodeVersion QT_FASTCALL unicodeVersion(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
 
-    static UnicodeVersion QT_FASTCALL currentUnicodeVersion() Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static UnicodeVersion QT_FASTCALL currentUnicodeVersion() noexcept Q_DECL_CONST_FUNCTION;
 
-    static bool QT_FASTCALL isPrint(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static Q_DECL_CONSTEXPR inline bool isSpace(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION
+    static bool QT_FASTCALL isPrint(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static Q_DECL_CONSTEXPR inline bool isSpace(uint ucs4) noexcept Q_DECL_CONST_FUNCTION
     {
         // note that [0x09..0x0d] + 0x85 are exceptional Cc-s and must be handled explicitly
         return ucs4 == 0x20 || (ucs4 <= 0x0d && ucs4 >= 0x09)
                 || (ucs4 > 127 && (ucs4 == 0x85 || ucs4 == 0xa0 || QChar::isSpace_helper(ucs4)));
     }
-    static bool QT_FASTCALL isMark(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static bool QT_FASTCALL isPunct(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static bool QT_FASTCALL isSymbol(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static Q_DECL_CONSTEXPR inline bool isLetter(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION
+    static bool QT_FASTCALL isMark(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static bool QT_FASTCALL isPunct(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static bool QT_FASTCALL isSymbol(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static Q_DECL_CONSTEXPR inline bool isLetter(uint ucs4) noexcept Q_DECL_CONST_FUNCTION
     {
         return (ucs4 >= 'A' && ucs4 <= 'z' && (ucs4 >= 'a' || ucs4 <= 'Z'))
                 || (ucs4 > 127 && QChar::isLetter_helper(ucs4));
     }
-    static Q_DECL_CONSTEXPR inline bool isNumber(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION
+    static Q_DECL_CONSTEXPR inline bool isNumber(uint ucs4) noexcept Q_DECL_CONST_FUNCTION
     { return (ucs4 <= '9' && ucs4 >= '0') || (ucs4 > 127 && QChar::isNumber_helper(ucs4)); }
-    static Q_DECL_CONSTEXPR inline bool isLetterOrNumber(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION
+    static Q_DECL_CONSTEXPR inline bool isLetterOrNumber(uint ucs4) noexcept Q_DECL_CONST_FUNCTION
     {
         return (ucs4 >= 'A' && ucs4 <= 'z' && (ucs4 >= 'a' || ucs4 <= 'Z'))
                 || (ucs4 >= '0' && ucs4 <= '9')
                 || (ucs4 > 127 && QChar::isLetterOrNumber_helper(ucs4));
     }
-    static Q_DECL_CONSTEXPR inline bool isDigit(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION
+    static Q_DECL_CONSTEXPR inline bool isDigit(uint ucs4) noexcept Q_DECL_CONST_FUNCTION
     { return (ucs4 <= '9' && ucs4 >= '0') || (ucs4 > 127 && QChar::category(ucs4) == Number_DecimalDigit); }
-    static Q_DECL_CONSTEXPR inline bool isLower(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION
+    static Q_DECL_CONSTEXPR inline bool isLower(uint ucs4) noexcept Q_DECL_CONST_FUNCTION
     { return (ucs4 <= 'z' && ucs4 >= 'a') || (ucs4 > 127 && QChar::category(ucs4) == Letter_Lowercase); }
-    static Q_DECL_CONSTEXPR inline bool isUpper(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION
+    static Q_DECL_CONSTEXPR inline bool isUpper(uint ucs4) noexcept Q_DECL_CONST_FUNCTION
     { return (ucs4 <= 'Z' && ucs4 >= 'A') || (ucs4 > 127 && QChar::category(ucs4) == Letter_Uppercase); }
-    static Q_DECL_CONSTEXPR inline bool isTitleCase(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION
+    static Q_DECL_CONSTEXPR inline bool isTitleCase(uint ucs4) noexcept Q_DECL_CONST_FUNCTION
     { return ucs4 > 127 && QChar::category(ucs4) == Letter_Titlecase; }
 
 private:
-    static bool QT_FASTCALL isSpace_helper(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static bool QT_FASTCALL isLetter_helper(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static bool QT_FASTCALL isNumber_helper(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
-    static bool QT_FASTCALL isLetterOrNumber_helper(uint ucs4) Q_DECL_NOTHROW Q_DECL_CONST_FUNCTION;
+    static bool QT_FASTCALL isSpace_helper(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static bool QT_FASTCALL isLetter_helper(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static bool QT_FASTCALL isNumber_helper(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
+    static bool QT_FASTCALL isLetterOrNumber_helper(uint ucs4) noexcept Q_DECL_CONST_FUNCTION;
 
 #ifdef QT_NO_CAST_FROM_ASCII
-    QChar(char c) Q_DECL_NOTHROW;
-    QChar(uchar c) Q_DECL_NOTHROW;
+    QChar(char c) noexcept;
+    QChar(uchar c) noexcept;
 #endif
 
-    friend Q_DECL_CONSTEXPR bool operator==(QChar, QChar) Q_DECL_NOTHROW;
-    friend Q_DECL_CONSTEXPR bool operator< (QChar, QChar) Q_DECL_NOTHROW;
+    friend Q_DECL_CONSTEXPR bool operator==(QChar, QChar) noexcept;
+    friend Q_DECL_CONSTEXPR bool operator< (QChar, QChar) noexcept;
     ushort ucs;
 };
 
 Q_DECLARE_TYPEINFO(QChar, Q_MOVABLE_TYPE);
 
-Q_DECL_CONSTEXPR inline bool operator==(QChar c1, QChar c2) Q_DECL_NOTHROW { return c1.ucs == c2.ucs; }
-Q_DECL_CONSTEXPR inline bool operator< (QChar c1, QChar c2) Q_DECL_NOTHROW { return c1.ucs <  c2.ucs; }
+Q_DECL_CONSTEXPR inline bool operator==(QChar c1, QChar c2) noexcept { return c1.ucs == c2.ucs; }
+Q_DECL_CONSTEXPR inline bool operator< (QChar c1, QChar c2) noexcept { return c1.ucs <  c2.ucs; }
 
-Q_DECL_CONSTEXPR inline bool operator!=(QChar c1, QChar c2) Q_DECL_NOTHROW { return !operator==(c1, c2); }
-Q_DECL_CONSTEXPR inline bool operator>=(QChar c1, QChar c2) Q_DECL_NOTHROW { return !operator< (c1, c2); }
-Q_DECL_CONSTEXPR inline bool operator> (QChar c1, QChar c2) Q_DECL_NOTHROW { return  operator< (c2, c1); }
-Q_DECL_CONSTEXPR inline bool operator<=(QChar c1, QChar c2) Q_DECL_NOTHROW { return !operator< (c2, c1); }
+Q_DECL_CONSTEXPR inline bool operator!=(QChar c1, QChar c2) noexcept { return !operator==(c1, c2); }
+Q_DECL_CONSTEXPR inline bool operator>=(QChar c1, QChar c2) noexcept { return !operator< (c1, c2); }
+Q_DECL_CONSTEXPR inline bool operator> (QChar c1, QChar c2) noexcept { return  operator< (c2, c1); }
+Q_DECL_CONSTEXPR inline bool operator<=(QChar c1, QChar c2) noexcept { return !operator< (c2, c1); }
 
 
-Q_DECL_CONSTEXPR inline bool operator==(QChar lhs, std::nullptr_t) Q_DECL_NOTHROW { return lhs.isNull(); }
-Q_DECL_CONSTEXPR inline bool operator< (QChar,     std::nullptr_t) Q_DECL_NOTHROW { return false; }
-Q_DECL_CONSTEXPR inline bool operator==(std::nullptr_t, QChar rhs) Q_DECL_NOTHROW { return rhs.isNull(); }
-Q_DECL_CONSTEXPR inline bool operator< (std::nullptr_t, QChar rhs) Q_DECL_NOTHROW { return !rhs.isNull(); }
+Q_DECL_CONSTEXPR inline bool operator==(QChar lhs, std::nullptr_t) noexcept { return lhs.isNull(); }
+Q_DECL_CONSTEXPR inline bool operator< (QChar,     std::nullptr_t) noexcept { return false; }
+Q_DECL_CONSTEXPR inline bool operator==(std::nullptr_t, QChar rhs) noexcept { return rhs.isNull(); }
+Q_DECL_CONSTEXPR inline bool operator< (std::nullptr_t, QChar rhs) noexcept { return !rhs.isNull(); }
 
-Q_DECL_CONSTEXPR inline bool operator!=(QChar lhs, std::nullptr_t) Q_DECL_NOTHROW { return !operator==(lhs, nullptr); }
-Q_DECL_CONSTEXPR inline bool operator>=(QChar lhs, std::nullptr_t) Q_DECL_NOTHROW { return !operator< (lhs, nullptr); }
-Q_DECL_CONSTEXPR inline bool operator> (QChar lhs, std::nullptr_t) Q_DECL_NOTHROW { return  operator< (nullptr, lhs); }
-Q_DECL_CONSTEXPR inline bool operator<=(QChar lhs, std::nullptr_t) Q_DECL_NOTHROW { return !operator< (nullptr, lhs); }
+Q_DECL_CONSTEXPR inline bool operator!=(QChar lhs, std::nullptr_t) noexcept { return !operator==(lhs, nullptr); }
+Q_DECL_CONSTEXPR inline bool operator>=(QChar lhs, std::nullptr_t) noexcept { return !operator< (lhs, nullptr); }
+Q_DECL_CONSTEXPR inline bool operator> (QChar lhs, std::nullptr_t) noexcept { return  operator< (nullptr, lhs); }
+Q_DECL_CONSTEXPR inline bool operator<=(QChar lhs, std::nullptr_t) noexcept { return !operator< (nullptr, lhs); }
 
-Q_DECL_CONSTEXPR inline bool operator!=(std::nullptr_t, QChar rhs) Q_DECL_NOTHROW { return !operator==(nullptr, rhs); }
-Q_DECL_CONSTEXPR inline bool operator>=(std::nullptr_t, QChar rhs) Q_DECL_NOTHROW { return !operator< (nullptr, rhs); }
-Q_DECL_CONSTEXPR inline bool operator> (std::nullptr_t, QChar rhs) Q_DECL_NOTHROW { return  operator< (rhs, nullptr); }
-Q_DECL_CONSTEXPR inline bool operator<=(std::nullptr_t, QChar rhs) Q_DECL_NOTHROW { return !operator< (rhs, nullptr); }
+Q_DECL_CONSTEXPR inline bool operator!=(std::nullptr_t, QChar rhs) noexcept { return !operator==(nullptr, rhs); }
+Q_DECL_CONSTEXPR inline bool operator>=(std::nullptr_t, QChar rhs) noexcept { return !operator< (nullptr, rhs); }
+Q_DECL_CONSTEXPR inline bool operator> (std::nullptr_t, QChar rhs) noexcept { return  operator< (rhs, nullptr); }
+Q_DECL_CONSTEXPR inline bool operator<=(std::nullptr_t, QChar rhs) noexcept { return !operator< (rhs, nullptr); }
 
 #ifndef QT_NO_DATASTREAM
 Q_CORE_EXPORT QDataStream &operator<<(QDataStream &, QChar);
diff --git a/src/corelib/tools/qcollator.h b/src/corelib/tools/qcollator.h
index 700de739bb..6c76ef038f 100644
--- a/src/corelib/tools/qcollator.h
+++ b/src/corelib/tools/qcollator.h
@@ -58,10 +58,10 @@ public:
     ~QCollatorSortKey();
     QCollatorSortKey &operator=(const QCollatorSortKey &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QCollatorSortKey &operator=(QCollatorSortKey &&other) Q_DECL_NOTHROW
+    inline QCollatorSortKey &operator=(QCollatorSortKey &&other) noexcept
     { swap(other); return *this; }
 #endif
-    void swap(QCollatorSortKey &other) Q_DECL_NOTHROW
+    void swap(QCollatorSortKey &other) noexcept
     { d.swap(other.d); }
 
     int compare(const QCollatorSortKey &key) const;
@@ -88,13 +88,13 @@ public:
     ~QCollator();
     QCollator &operator=(const QCollator &);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QCollator(QCollator &&other) Q_DECL_NOTHROW
+    QCollator(QCollator &&other) noexcept
         : d(other.d) { other.d = nullptr; }
-    QCollator &operator=(QCollator &&other) Q_DECL_NOTHROW
+    QCollator &operator=(QCollator &&other) noexcept
     { swap(other); return *this; }
 #endif
 
-    void swap(QCollator &other) Q_DECL_NOTHROW
+    void swap(QCollator &other) noexcept
     { qSwap(d, other.d); }
 
     void setLocale(const QLocale &locale);
diff --git a/src/corelib/tools/qcommandlineoption.cpp b/src/corelib/tools/qcommandlineoption.cpp
index c2b86014ba..aff684fad2 100644
--- a/src/corelib/tools/qcommandlineoption.cpp
+++ b/src/corelib/tools/qcommandlineoption.cpp
@@ -254,7 +254,7 @@ namespace {
         typedef QString argument_type;
 
         Q_NEVER_INLINE
-        result_type operator()(const QString &name) const Q_DECL_NOEXCEPT
+        result_type operator()(const QString &name) const noexcept
         {
             if (Q_UNLIKELY(name.isEmpty()))
                 return warn("be empty");
@@ -271,7 +271,7 @@ namespace {
         }
 
         Q_NEVER_INLINE
-        static bool warn(const char *what) Q_DECL_NOEXCEPT
+        static bool warn(const char *what) noexcept
         {
             qWarning("QCommandLineOption: Option names cannot %s", what);
             return true;
diff --git a/src/corelib/tools/qcommandlineoption.h b/src/corelib/tools/qcommandlineoption.h
index 276be042de..643427f6fb 100644
--- a/src/corelib/tools/qcommandlineoption.h
+++ b/src/corelib/tools/qcommandlineoption.h
@@ -72,10 +72,10 @@ public:
 
     QCommandLineOption &operator=(const QCommandLineOption &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QCommandLineOption &operator=(QCommandLineOption &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QCommandLineOption &operator=(QCommandLineOption &&other) noexcept { swap(other); return *this; }
 #endif
 
-    void swap(QCommandLineOption &other) Q_DECL_NOTHROW
+    void swap(QCommandLineOption &other) noexcept
     { qSwap(d, other.d); }
 
     QStringList names() const;
diff --git a/src/corelib/tools/qdatetime.cpp b/src/corelib/tools/qdatetime.cpp
index d06b8a04d2..54e52c4cd1 100644
--- a/src/corelib/tools/qdatetime.cpp
+++ b/src/corelib/tools/qdatetime.cpp
@@ -256,7 +256,7 @@ static QString toOffsetString(Qt::DateFormat format, int offset)
 
 #if QT_CONFIG(datestring)
 // Parse offset in [+-]HH[[:]mm] format
-static int fromOffsetString(const QStringRef &offsetString, bool *valid) Q_DECL_NOTHROW
+static int fromOffsetString(const QStringRef &offsetString, bool *valid) noexcept
 {
     *valid = false;
 
@@ -3210,7 +3210,7 @@ QDateTime::QDateTime(const QDate &date, const QTime &time, const QTimeZone &time
 /*!
     Constructs a copy of the \a other datetime.
 */
-QDateTime::QDateTime(const QDateTime &other) Q_DECL_NOTHROW
+QDateTime::QDateTime(const QDateTime &other) noexcept
     : d(other.d)
 {
 }
@@ -3220,7 +3220,7 @@ QDateTime::QDateTime(const QDateTime &other) Q_DECL_NOTHROW
     Moves the content of the temporary \a other datetime to this object and
     leaves \a other in an unspecified (but proper) state.
 */
-QDateTime::QDateTime(QDateTime &&other) Q_DECL_NOTHROW
+QDateTime::QDateTime(QDateTime &&other) noexcept
     : d(std::move(other.d))
 {
 }
@@ -3237,7 +3237,7 @@ QDateTime::~QDateTime()
     copy.
 */
 
-QDateTime &QDateTime::operator=(const QDateTime &other) Q_DECL_NOTHROW
+QDateTime &QDateTime::operator=(const QDateTime &other) noexcept
 {
     d = other.d;
     return *this;
@@ -4465,7 +4465,7 @@ QDateTime QDateTime::currentDateTimeUtc()
     return QDateTime(d, t, Qt::UTC);
 }
 
-qint64 QDateTime::currentMSecsSinceEpoch() Q_DECL_NOTHROW
+qint64 QDateTime::currentMSecsSinceEpoch() noexcept
 {
     SYSTEMTIME st;
     memset(&st, 0, sizeof(SYSTEMTIME));
@@ -4476,7 +4476,7 @@ qint64 QDateTime::currentMSecsSinceEpoch() Q_DECL_NOTHROW
                    - julianDayFromDate(1970, 1, 1)) * Q_INT64_C(86400000);
 }
 
-qint64 QDateTime::currentSecsSinceEpoch() Q_DECL_NOTHROW
+qint64 QDateTime::currentSecsSinceEpoch() noexcept
 {
     SYSTEMTIME st;
     memset(&st, 0, sizeof(SYSTEMTIME));
@@ -4508,7 +4508,7 @@ QDateTime QDateTime::currentDateTimeUtc()
     return fromMSecsSinceEpoch(currentMSecsSinceEpoch(), Qt::UTC);
 }
 
-qint64 QDateTime::currentMSecsSinceEpoch() Q_DECL_NOTHROW
+qint64 QDateTime::currentMSecsSinceEpoch() noexcept
 {
     // posix compliant system
     // we have milliseconds
@@ -4517,7 +4517,7 @@ qint64 QDateTime::currentMSecsSinceEpoch() Q_DECL_NOTHROW
     return qint64(tv.tv_sec) * Q_INT64_C(1000) + tv.tv_usec / 1000;
 }
 
-qint64 QDateTime::currentSecsSinceEpoch() Q_DECL_NOTHROW
+qint64 QDateTime::currentSecsSinceEpoch() noexcept
 {
     struct timeval tv;
     gettimeofday(&tv, 0);
@@ -5414,7 +5414,7 @@ uint qHash(const QDateTime &key, uint seed)
 
     Returns the hash value for the \a key, using \a seed to seed the calculation.
 */
-uint qHash(const QDate &key, uint seed) Q_DECL_NOTHROW
+uint qHash(const QDate &key, uint seed) noexcept
 {
     return qHash(key.toJulianDay(), seed);
 }
@@ -5425,7 +5425,7 @@ uint qHash(const QDate &key, uint seed) Q_DECL_NOTHROW
 
     Returns the hash value for the \a key, using \a seed to seed the calculation.
 */
-uint qHash(const QTime &key, uint seed) Q_DECL_NOTHROW
+uint qHash(const QTime &key, uint seed) noexcept
 {
     return qHash(key.msecsSinceStartOfDay(), seed);
 }
diff --git a/src/corelib/tools/qdatetime.h b/src/corelib/tools/qdatetime.h
index 43271b34ed..144fb9b28a 100644
--- a/src/corelib/tools/qdatetime.h
+++ b/src/corelib/tools/qdatetime.h
@@ -266,16 +266,16 @@ public:
 #if QT_CONFIG(timezone)
     QDateTime(const QDate &date, const QTime &time, const QTimeZone &timeZone);
 #endif // timezone
-    QDateTime(const QDateTime &other) Q_DECL_NOTHROW;
-    QDateTime(QDateTime &&other) Q_DECL_NOTHROW;
+    QDateTime(const QDateTime &other) noexcept;
+    QDateTime(QDateTime &&other) noexcept;
     ~QDateTime();
 
 #ifdef Q_COMPILER_RVALUE_REFS
-    QDateTime &operator=(QDateTime &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QDateTime &operator=(QDateTime &&other) noexcept { swap(other); return *this; }
 #endif
-    QDateTime &operator=(const QDateTime &other) Q_DECL_NOTHROW;
+    QDateTime &operator=(const QDateTime &other) noexcept;
 
-    void swap(QDateTime &other) Q_DECL_NOTHROW { qSwap(d.d, other.d.d); }
+    void swap(QDateTime &other) noexcept { qSwap(d.d, other.d.d); }
 
     bool isNull() const;
     bool isValid() const;
@@ -366,8 +366,8 @@ public:
     static QDateTime fromSecsSinceEpoch(qint64 secs, const QTimeZone &timeZone);
 #endif
 
-    static qint64 currentMSecsSinceEpoch() Q_DECL_NOTHROW;
-    static qint64 currentSecsSinceEpoch() Q_DECL_NOTHROW;
+    static qint64 currentMSecsSinceEpoch() noexcept;
+    static qint64 currentSecsSinceEpoch() noexcept;
 
 #if defined(Q_OS_DARWIN) || defined(Q_QDOC)
     static QDateTime fromCFDate(CFDateRef date);
@@ -410,8 +410,8 @@ Q_CORE_EXPORT QDebug operator<<(QDebug, const QDateTime &);
 // QDateTime is not noexcept for now -- to be revised once
 // timezone and calendaring support is added
 Q_CORE_EXPORT uint qHash(const QDateTime &key, uint seed = 0);
-Q_CORE_EXPORT uint qHash(const QDate &key, uint seed = 0) Q_DECL_NOTHROW;
-Q_CORE_EXPORT uint qHash(const QTime &key, uint seed = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT uint qHash(const QDate &key, uint seed = 0) noexcept;
+Q_CORE_EXPORT uint qHash(const QTime &key, uint seed = 0) noexcept;
 
 QT_END_NAMESPACE
 
diff --git a/src/corelib/tools/qeasingcurve.h b/src/corelib/tools/qeasingcurve.h
index 74bde5825a..1791f19199 100644
--- a/src/corelib/tools/qeasingcurve.h
+++ b/src/corelib/tools/qeasingcurve.h
@@ -81,12 +81,12 @@ public:
     QEasingCurve &operator=(const QEasingCurve &other)
     { if ( this != &other ) { QEasingCurve copy(other); swap(copy); } return *this; }
 #ifdef Q_COMPILER_RVALUE_REFS
-    QEasingCurve(QEasingCurve &&other) Q_DECL_NOTHROW : d_ptr(other.d_ptr) { other.d_ptr = nullptr; }
-    QEasingCurve &operator=(QEasingCurve &&other) Q_DECL_NOTHROW
+    QEasingCurve(QEasingCurve &&other) noexcept : d_ptr(other.d_ptr) { other.d_ptr = nullptr; }
+    QEasingCurve &operator=(QEasingCurve &&other) noexcept
     { qSwap(d_ptr, other.d_ptr); return *this; }
 #endif
 
-    void swap(QEasingCurve &other) Q_DECL_NOTHROW { qSwap(d_ptr, other.d_ptr); }
+    void swap(QEasingCurve &other) noexcept { qSwap(d_ptr, other.d_ptr); }
 
     bool operator==(const QEasingCurve &other) const;
     inline bool operator!=(const QEasingCurve &other) const
diff --git a/src/corelib/tools/qhash.cpp b/src/corelib/tools/qhash.cpp
index 32e9a4269c..dd22a38be1 100644
--- a/src/corelib/tools/qhash.cpp
+++ b/src/corelib/tools/qhash.cpp
@@ -197,7 +197,7 @@ static uint crc32(...)
 }
 #endif
 
-static inline uint hash(const uchar *p, size_t len, uint seed) Q_DECL_NOTHROW
+static inline uint hash(const uchar *p, size_t len, uint seed) noexcept
 {
     uint h = seed;
 
@@ -210,12 +210,12 @@ static inline uint hash(const uchar *p, size_t len, uint seed) Q_DECL_NOTHROW
     return h;
 }
 
-uint qHashBits(const void *p, size_t len, uint seed) Q_DECL_NOTHROW
+uint qHashBits(const void *p, size_t len, uint seed) noexcept
 {
     return hash(static_cast<const uchar*>(p), int(len), seed);
 }
 
-static inline uint hash(const QChar *p, size_t len, uint seed) Q_DECL_NOTHROW
+static inline uint hash(const QChar *p, size_t len, uint seed) noexcept
 {
     uint h = seed;
 
@@ -228,29 +228,29 @@ static inline uint hash(const QChar *p, size_t len, uint seed) Q_DECL_NOTHROW
     return h;
 }
 
-uint qHash(const QByteArray &key, uint seed) Q_DECL_NOTHROW
+uint qHash(const QByteArray &key, uint seed) noexcept
 {
     return hash(reinterpret_cast<const uchar *>(key.constData()), size_t(key.size()), seed);
 }
 
 #if QT_STRINGVIEW_LEVEL < 2
-uint qHash(const QString &key, uint seed) Q_DECL_NOTHROW
+uint qHash(const QString &key, uint seed) noexcept
 {
     return hash(key.unicode(), size_t(key.size()), seed);
 }
 
-uint qHash(const QStringRef &key, uint seed) Q_DECL_NOTHROW
+uint qHash(const QStringRef &key, uint seed) noexcept
 {
     return hash(key.unicode(), size_t(key.size()), seed);
 }
 #endif
 
-uint qHash(QStringView key, uint seed) Q_DECL_NOTHROW
+uint qHash(QStringView key, uint seed) noexcept
 {
     return hash(key.data(), key.size(), seed);
 }
 
-uint qHash(const QBitArray &bitArray, uint seed) Q_DECL_NOTHROW
+uint qHash(const QBitArray &bitArray, uint seed) noexcept
 {
     int m = bitArray.d.size() - 1;
     uint result = hash(reinterpret_cast<const uchar *>(bitArray.d.constData()),
@@ -264,7 +264,7 @@ uint qHash(const QBitArray &bitArray, uint seed) Q_DECL_NOTHROW
     return result;
 }
 
-uint qHash(QLatin1String key, uint seed) Q_DECL_NOTHROW
+uint qHash(QLatin1String key, uint seed) noexcept
 {
     return hash(reinterpret_cast<const uchar *>(key.data()), size_t(key.size()), seed);
 }
@@ -398,7 +398,7 @@ void qSetGlobalQHashSeed(int newSeed)
     This function can hash discontiguous memory by invoking it on each chunk,
     passing the previous's result in the next call's \a chained argument.
 */
-uint qt_hash(QStringView key, uint chained) Q_DECL_NOTHROW
+uint qt_hash(QStringView key, uint chained) noexcept
 {
     auto n = key.size();
     auto p = key.utf16();
@@ -938,7 +938,7 @@ void QHashData::checkSanity()
 
     Returns the hash value for the \a key, using \a seed to seed the calculation.
 */
-uint qHash(float key, uint seed) Q_DECL_NOTHROW
+uint qHash(float key, uint seed) noexcept
 {
     return key != 0.0f ? hash(reinterpret_cast<const uchar *>(&key), sizeof(key), seed) : seed ;
 }
@@ -948,7 +948,7 @@ uint qHash(float key, uint seed) Q_DECL_NOTHROW
 
     Returns the hash value for the \a key, using \a seed to seed the calculation.
 */
-uint qHash(double key, uint seed) Q_DECL_NOTHROW
+uint qHash(double key, uint seed) noexcept
 {
     return key != 0.0  ? hash(reinterpret_cast<const uchar *>(&key), sizeof(key), seed) : seed ;
 }
@@ -959,7 +959,7 @@ uint qHash(double key, uint seed) Q_DECL_NOTHROW
 
     Returns the hash value for the \a key, using \a seed to seed the calculation.
 */
-uint qHash(long double key, uint seed) Q_DECL_NOTHROW
+uint qHash(long double key, uint seed) noexcept
 {
     return key != 0.0L ? hash(reinterpret_cast<const uchar *>(&key), sizeof(key), seed) : seed ;
 }
diff --git a/src/corelib/tools/qhash.h b/src/corelib/tools/qhash.h
index a586ca5671..9a733180a5 100644
--- a/src/corelib/tools/qhash.h
+++ b/src/corelib/tools/qhash.h
@@ -240,7 +240,7 @@ class QHash
     static inline int alignOfNode() { return qMax<int>(sizeof(void*), Q_ALIGNOF(Node)); }
 
 public:
-    inline QHash() Q_DECL_NOTHROW : d(const_cast<QHashData *>(&QHashData::shared_null)) { }
+    inline QHash() noexcept : d(const_cast<QHashData *>(&QHashData::shared_null)) { }
 #ifdef Q_COMPILER_INITIALIZER_LISTS
     inline QHash(std::initializer_list<std::pair<Key,T> > list)
         : d(const_cast<QHashData *>(&QHashData::shared_null))
@@ -255,11 +255,11 @@ public:
 
     QHash &operator=(const QHash &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QHash(QHash &&other) Q_DECL_NOTHROW : d(other.d) { other.d = const_cast<QHashData *>(&QHashData::shared_null); }
-    QHash &operator=(QHash &&other) Q_DECL_NOTHROW
+    QHash(QHash &&other) noexcept : d(other.d) { other.d = const_cast<QHashData *>(&QHashData::shared_null); }
+    QHash &operator=(QHash &&other) noexcept
     { QHash moved(std::move(other)); swap(moved); return *this; }
 #endif
-    void swap(QHash &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    void swap(QHash &other) noexcept { qSwap(d, other.d); }
 
     bool operator==(const QHash &other) const;
     bool operator!=(const QHash &other) const { return !(*this == other); }
@@ -473,7 +473,7 @@ public:
     inline const_key_value_iterator constKeyValueEnd() const { return const_key_value_iterator(end()); }
 
     QPair<iterator, iterator> equal_range(const Key &key);
-    QPair<const_iterator, const_iterator> equal_range(const Key &key) const Q_DECL_NOTHROW;
+    QPair<const_iterator, const_iterator> equal_range(const Key &key) const noexcept;
     iterator erase(iterator it) { return erase(const_iterator(it.i)); }
     iterator erase(const_iterator it);
 
@@ -512,11 +512,11 @@ private:
 
     static void duplicateNode(QHashData::Node *originalNode, void *newNode);
 
-    bool isValidIterator(const iterator &it) const Q_DECL_NOTHROW
+    bool isValidIterator(const iterator &it) const noexcept
     { return isValidNode(it.i); }
-    bool isValidIterator(const const_iterator &it) const Q_DECL_NOTHROW
+    bool isValidIterator(const const_iterator &it) const noexcept
     { return isValidNode(it.i); }
-    bool isValidNode(QHashData::Node *node) const Q_DECL_NOTHROW
+    bool isValidNode(QHashData::Node *node) const noexcept
     {
 #if defined(QT_DEBUG) && !defined(Q_HASH_NO_ITERATOR_DEBUG)
         while (node->next)
@@ -993,7 +993,7 @@ QPair<typename QHash<Key, T>::iterator, typename QHash<Key, T>::iterator> QHash<
 }
 
 template <class Key, class T>
-QPair<typename QHash<Key, T>::const_iterator, typename QHash<Key, T>::const_iterator> QHash<Key, T>::equal_range(const Key &akey) const Q_DECL_NOTHROW
+QPair<typename QHash<Key, T>::const_iterator, typename QHash<Key, T>::const_iterator> QHash<Key, T>::equal_range(const Key &akey) const noexcept
 {
     Node *node = *findNode(akey);
     const_iterator firstIt = const_iterator(node);
@@ -1020,7 +1020,7 @@ template <class Key, class T>
 class QMultiHash : public QHash<Key, T>
 {
 public:
-    QMultiHash() Q_DECL_NOTHROW {}
+    QMultiHash() noexcept {}
 #ifdef Q_COMPILER_INITIALIZER_LISTS
     inline QMultiHash(std::initializer_list<std::pair<Key,T> > list)
     {
@@ -1034,9 +1034,9 @@ public:
 
     QMultiHash(const QHash<Key, T> &other) : QHash<Key, T>(other) {}
 #ifdef Q_COMPILER_RVALUE_REFS
-    QMultiHash(QHash<Key, T> &&other) Q_DECL_NOTHROW : QHash<Key, T>(std::move(other)) {}
+    QMultiHash(QHash<Key, T> &&other) noexcept : QHash<Key, T>(std::move(other)) {}
 #endif
-    void swap(QMultiHash &other) Q_DECL_NOTHROW { QHash<Key, T>::swap(other); } // prevent QMultiHash<->QHash swaps
+    void swap(QMultiHash &other) noexcept { QHash<Key, T>::swap(other); } // prevent QMultiHash<->QHash swaps
 
     inline typename QHash<Key, T>::iterator replace(const Key &key, const T &value)
     { return QHash<Key, T>::insert(key, value); }
diff --git a/src/corelib/tools/qhashfunctions.h b/src/corelib/tools/qhashfunctions.h
index d013c26d66..2d1ff01294 100644
--- a/src/corelib/tools/qhashfunctions.h
+++ b/src/corelib/tools/qhashfunctions.h
@@ -67,49 +67,49 @@ class QLatin1String;
 Q_CORE_EXPORT int qGlobalQHashSeed();
 Q_CORE_EXPORT void qSetGlobalQHashSeed(int newSeed);
 
-Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHashBits(const void *p, size_t size, uint seed = 0) Q_DECL_NOTHROW;
-
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(char key, uint seed = 0) Q_DECL_NOTHROW { return uint(key) ^ seed; }
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(uchar key, uint seed = 0) Q_DECL_NOTHROW { return uint(key) ^ seed; }
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(signed char key, uint seed = 0) Q_DECL_NOTHROW { return uint(key) ^ seed; }
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(ushort key, uint seed = 0) Q_DECL_NOTHROW { return uint(key) ^ seed; }
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(short key, uint seed = 0) Q_DECL_NOTHROW { return uint(key) ^ seed; }
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(uint key, uint seed = 0) Q_DECL_NOTHROW { return key ^ seed; }
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(int key, uint seed = 0) Q_DECL_NOTHROW { return uint(key) ^ seed; }
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(ulong key, uint seed = 0) Q_DECL_NOTHROW
+Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHashBits(const void *p, size_t size, uint seed = 0) noexcept;
+
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(char key, uint seed = 0) noexcept { return uint(key) ^ seed; }
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(uchar key, uint seed = 0) noexcept { return uint(key) ^ seed; }
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(signed char key, uint seed = 0) noexcept { return uint(key) ^ seed; }
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(ushort key, uint seed = 0) noexcept { return uint(key) ^ seed; }
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(short key, uint seed = 0) noexcept { return uint(key) ^ seed; }
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(uint key, uint seed = 0) noexcept { return key ^ seed; }
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(int key, uint seed = 0) noexcept { return uint(key) ^ seed; }
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(ulong key, uint seed = 0) noexcept
 {
     return (sizeof(ulong) > sizeof(uint))
         ? (uint(((key >> (8 * sizeof(uint) - 1)) ^ key) & (~0U)) ^ seed)
         : (uint(key & (~0U)) ^ seed);
 }
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(long key, uint seed = 0) Q_DECL_NOTHROW { return qHash(ulong(key), seed); }
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(quint64 key, uint seed = 0) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(long key, uint seed = 0) noexcept { return qHash(ulong(key), seed); }
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(quint64 key, uint seed = 0) noexcept
 {
     return uint(((key >> (8 * sizeof(uint) - 1)) ^ key) & (~0U)) ^ seed;
 }
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(qint64 key, uint seed = 0) Q_DECL_NOTHROW { return qHash(quint64(key), seed); }
-Q_CORE_EXPORT Q_DECL_CONST_FUNCTION uint qHash(float key, uint seed = 0) Q_DECL_NOTHROW;
-Q_CORE_EXPORT Q_DECL_CONST_FUNCTION uint qHash(double key, uint seed = 0) Q_DECL_NOTHROW;
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(qint64 key, uint seed = 0) noexcept { return qHash(quint64(key), seed); }
+Q_CORE_EXPORT Q_DECL_CONST_FUNCTION uint qHash(float key, uint seed = 0) noexcept;
+Q_CORE_EXPORT Q_DECL_CONST_FUNCTION uint qHash(double key, uint seed = 0) noexcept;
 #if !defined(Q_OS_DARWIN) || defined(Q_CLANG_QDOC)
-Q_CORE_EXPORT Q_DECL_CONST_FUNCTION uint qHash(long double key, uint seed = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT Q_DECL_CONST_FUNCTION uint qHash(long double key, uint seed = 0) noexcept;
 #endif
-Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(const QChar key, uint seed = 0) Q_DECL_NOTHROW { return qHash(key.unicode(), seed); }
-Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QByteArray &key, uint seed = 0) Q_DECL_NOTHROW;
+Q_DECL_CONST_FUNCTION Q_DECL_CONSTEXPR inline uint qHash(const QChar key, uint seed = 0) noexcept { return qHash(key.unicode(), seed); }
+Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QByteArray &key, uint seed = 0) noexcept;
 #if QT_STRINGVIEW_LEVEL < 2
-Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QString &key, uint seed = 0) Q_DECL_NOTHROW;
-Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QStringRef &key, uint seed = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QString &key, uint seed = 0) noexcept;
+Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QStringRef &key, uint seed = 0) noexcept;
 #endif
-Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(QStringView key, uint seed = 0) Q_DECL_NOTHROW;
-Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QBitArray &key, uint seed = 0) Q_DECL_NOTHROW;
-Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(QLatin1String key, uint seed = 0) Q_DECL_NOTHROW;
-Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qt_hash(QStringView key, uint chained = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(QStringView key, uint seed = 0) noexcept;
+Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(const QBitArray &key, uint seed = 0) noexcept;
+Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qHash(QLatin1String key, uint seed = 0) noexcept;
+Q_CORE_EXPORT Q_DECL_PURE_FUNCTION uint qt_hash(QStringView key, uint chained = 0) noexcept;
 
-Q_DECL_CONST_FUNCTION inline uint qHash(std::nullptr_t, uint seed = 0) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION inline uint qHash(std::nullptr_t, uint seed = 0) noexcept
 {
     return qHash(reinterpret_cast<quintptr>(nullptr), seed);
 }
 
-template <class T> inline uint qHash(const T *key, uint seed = 0) Q_DECL_NOTHROW
+template <class T> inline uint qHash(const T *key, uint seed = 0) noexcept
 {
     return qHash(reinterpret_cast<quintptr>(key), seed);
 }
diff --git a/src/corelib/tools/qiterator.h b/src/corelib/tools/qiterator.h
index 586d26cbad..90921af16e 100644
--- a/src/corelib/tools/qiterator.h
+++ b/src/corelib/tools/qiterator.h
@@ -197,8 +197,8 @@ public:
         return std::pair<Key, T>(i.key(), i.value());
     }
 
-    friend bool operator==(QKeyValueIterator lhs, QKeyValueIterator rhs) Q_DECL_NOEXCEPT { return lhs.i == rhs.i; }
-    friend bool operator!=(QKeyValueIterator lhs, QKeyValueIterator rhs) Q_DECL_NOEXCEPT { return lhs.i != rhs.i; }
+    friend bool operator==(QKeyValueIterator lhs, QKeyValueIterator rhs) noexcept { return lhs.i == rhs.i; }
+    friend bool operator!=(QKeyValueIterator lhs, QKeyValueIterator rhs) noexcept { return lhs.i != rhs.i; }
 
     inline QKeyValueIterator &operator++() { ++i; return *this; }
     inline QKeyValueIterator operator++(int) { return QKeyValueIterator(i++);}
diff --git a/src/corelib/tools/qlinkedlist.h b/src/corelib/tools/qlinkedlist.h
index 1e6d4df474..91367a74b3 100644
--- a/src/corelib/tools/qlinkedlist.h
+++ b/src/corelib/tools/qlinkedlist.h
@@ -80,7 +80,7 @@ class QLinkedList
     union { QLinkedListData *d; QLinkedListNode<T> *e; };
 
 public:
-    inline QLinkedList() Q_DECL_NOTHROW : d(const_cast<QLinkedListData *>(&QLinkedListData::shared_null)) { }
+    inline QLinkedList() noexcept : d(const_cast<QLinkedListData *>(&QLinkedListData::shared_null)) { }
     inline QLinkedList(const QLinkedList<T> &l) : d(l.d) { d->ref.ref(); if (!d->sharable) detach(); }
 #if defined(Q_COMPILER_INITIALIZER_LISTS)
     inline QLinkedList(std::initializer_list<T> list)
@@ -92,12 +92,12 @@ public:
     ~QLinkedList();
     QLinkedList<T> &operator=(const QLinkedList<T> &);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QLinkedList(QLinkedList<T> &&other) Q_DECL_NOTHROW
+    QLinkedList(QLinkedList<T> &&other) noexcept
         : d(other.d) { other.d = const_cast<QLinkedListData *>(&QLinkedListData::shared_null); }
-    QLinkedList<T> &operator=(QLinkedList<T> &&other) Q_DECL_NOTHROW
+    QLinkedList<T> &operator=(QLinkedList<T> &&other) noexcept
     { QLinkedList moved(std::move(other)); swap(moved); return *this; }
 #endif
-    inline void swap(QLinkedList<T> &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    inline void swap(QLinkedList<T> &other) noexcept { qSwap(d, other.d); }
     bool operator==(const QLinkedList<T> &l) const;
     inline bool operator!=(const QLinkedList<T> &l) const { return !(*this == l); }
 
@@ -137,10 +137,10 @@ public:
         inline iterator() : i(nullptr) {}
         inline iterator(Node *n) : i(n) {}
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
-        iterator(const iterator &other) Q_DECL_NOTHROW : i(other.i) {}
-        iterator &operator=(const iterator &other) Q_DECL_NOTHROW { i = other.i; return *this; }
-        iterator(iterator &&other) Q_DECL_NOTHROW : i(other.i) {}
-        iterator &operator=(iterator &&other) Q_DECL_NOTHROW { return *this = other; }
+        iterator(const iterator &other) noexcept : i(other.i) {}
+        iterator &operator=(const iterator &other) noexcept { i = other.i; return *this; }
+        iterator(iterator &&other) noexcept : i(other.i) {}
+        iterator &operator=(iterator &&other) noexcept { return *this = other; }
 #endif
         inline T &operator*() const { return i->t; }
         inline T *operator->() const { return &i->t; }
@@ -176,10 +176,10 @@ public:
         inline const_iterator(Node *n) : i(n) {}
         inline const_iterator(iterator ci) : i(ci.i){}
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
-        const_iterator(const const_iterator &other) Q_DECL_NOTHROW : i(other.i) {}
-        const_iterator &operator=(const const_iterator &other) Q_DECL_NOTHROW { i = other.i; return *this; }
-        const_iterator(const_iterator &&other) Q_DECL_NOTHROW : i(other.i) {}
-        const_iterator &operator=(const_iterator &&other) Q_DECL_NOTHROW { return *this = other; }
+        const_iterator(const const_iterator &other) noexcept : i(other.i) {}
+        const_iterator &operator=(const const_iterator &other) noexcept { i = other.i; return *this; }
+        const_iterator(const_iterator &&other) noexcept : i(other.i) {}
+        const_iterator &operator=(const_iterator &&other) noexcept { return *this = other; }
 #endif
         inline const T &operator*() const { return i->t; }
         inline const T *operator->() const { return &i->t; }
@@ -203,20 +203,20 @@ public:
     typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
 
     inline iterator begin() { detach(); return e->n; }
-    inline const_iterator begin() const Q_DECL_NOTHROW { return e->n; }
-    inline const_iterator cbegin() const Q_DECL_NOTHROW { return e->n; }
-    inline const_iterator constBegin() const Q_DECL_NOTHROW { return e->n; }
+    inline const_iterator begin() const noexcept { return e->n; }
+    inline const_iterator cbegin() const noexcept { return e->n; }
+    inline const_iterator constBegin() const noexcept { return e->n; }
     inline iterator end() { detach(); return e; }
-    inline const_iterator end() const Q_DECL_NOTHROW { return e; }
-    inline const_iterator cend() const Q_DECL_NOTHROW { return e; }
-    inline const_iterator constEnd() const Q_DECL_NOTHROW { return e; }
+    inline const_iterator end() const noexcept { return e; }
+    inline const_iterator cend() const noexcept { return e; }
+    inline const_iterator constEnd() const noexcept { return e; }
 
     reverse_iterator rbegin() { return reverse_iterator(end()); }
     reverse_iterator rend() { return reverse_iterator(begin()); }
-    const_reverse_iterator rbegin() const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    const_reverse_iterator rend() const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
-    const_reverse_iterator crbegin() const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    const_reverse_iterator crend() const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
+    const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
+    const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
+    const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
+    const_reverse_iterator crend() const noexcept { return const_reverse_iterator(begin()); }
 
     iterator insert(iterator before, const T &t);
     iterator erase(iterator pos);
diff --git a/src/corelib/tools/qlist.h b/src/corelib/tools/qlist.h
index 34577acaa5..3371920ffc 100644
--- a/src/corelib/tools/qlist.h
+++ b/src/corelib/tools/qlist.h
@@ -111,11 +111,11 @@ struct Q_CORE_EXPORT QListData {
     void remove(int i);
     void remove(int i, int n);
     void move(int from, int to);
-    inline int size() const Q_DECL_NOTHROW { return d->end - d->begin; }
-    inline bool isEmpty() const Q_DECL_NOTHROW { return d->end  == d->begin; }
-    inline void **at(int i) const Q_DECL_NOTHROW { return d->array + d->begin + i; }
-    inline void **begin() const Q_DECL_NOTHROW { return d->array + d->begin; }
-    inline void **end() const Q_DECL_NOTHROW { return d->array + d->end; }
+    inline int size() const noexcept { return d->end - d->begin; }
+    inline bool isEmpty() const noexcept { return d->end  == d->begin; }
+    inline void **at(int i) const noexcept { return d->array + d->begin + i; }
+    inline void **begin() const noexcept { return d->array + d->begin; }
+    inline void **end() const noexcept { return d->array + d->end; }
 };
 
 namespace QtPrivate {
@@ -156,17 +156,17 @@ private:
     union { QListData p; QListData::Data *d; };
 
 public:
-    inline QList() Q_DECL_NOTHROW : d(const_cast<QListData::Data *>(&QListData::shared_null)) { }
+    inline QList() noexcept : d(const_cast<QListData::Data *>(&QListData::shared_null)) { }
     QList(const QList<T> &l);
     ~QList();
     QList<T> &operator=(const QList<T> &l);
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QList(QList<T> &&other) Q_DECL_NOTHROW
+    inline QList(QList<T> &&other) noexcept
         : d(other.d) { other.d = const_cast<QListData::Data *>(&QListData::shared_null); }
-    inline QList &operator=(QList<T> &&other) Q_DECL_NOTHROW
+    inline QList &operator=(QList<T> &&other) noexcept
     { QList moved(std::move(other)); swap(moved); return *this; }
 #endif
-    inline void swap(QList<T> &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    inline void swap(QList<T> &other) noexcept { qSwap(d, other.d); }
 #ifdef Q_COMPILER_INITIALIZER_LISTS
     inline QList(std::initializer_list<T> args)
         : d(const_cast<QListData::Data *>(&QListData::shared_null))
@@ -175,7 +175,7 @@ public:
     bool operator==(const QList<T> &l) const;
     inline bool operator!=(const QList<T> &l) const { return !(*this == l); }
 
-    inline int size() const Q_DECL_NOTHROW { return p.size(); }
+    inline int size() const noexcept { return p.size(); }
 
     inline void detach() { if (d->ref.isShared()) detach_helper(); }
 
@@ -198,9 +198,9 @@ public:
             d->ref.setSharable(sharable);
     }
 #endif
-    inline bool isSharedWith(const QList<T> &other) const Q_DECL_NOTHROW { return d == other.d; }
+    inline bool isSharedWith(const QList<T> &other) const noexcept { return d == other.d; }
 
-    inline bool isEmpty() const Q_DECL_NOTHROW { return p.isEmpty(); }
+    inline bool isEmpty() const noexcept { return p.isEmpty(); }
 
     void clear();
 
@@ -243,34 +243,34 @@ public:
         typedef T *pointer;
         typedef T &reference;
 
-        inline iterator() Q_DECL_NOTHROW : i(nullptr) {}
-        inline iterator(Node *n) Q_DECL_NOTHROW : i(n) {}
+        inline iterator() noexcept : i(nullptr) {}
+        inline iterator(Node *n) noexcept : i(n) {}
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
         // can't remove it in Qt 5, since doing so would make the type trivial,
         // which changes the way it's passed to functions by value.
-        inline iterator(const iterator &o) Q_DECL_NOTHROW : i(o.i){}
+        inline iterator(const iterator &o) noexcept : i(o.i){}
 #endif
         inline T &operator*() const { return i->t(); }
         inline T *operator->() const { return &i->t(); }
         inline T &operator[](difference_type j) const { return i[j].t(); }
-        inline bool operator==(const iterator &o) const Q_DECL_NOTHROW { return i == o.i; }
-        inline bool operator!=(const iterator &o) const Q_DECL_NOTHROW { return i != o.i; }
-        inline bool operator<(const iterator& other) const Q_DECL_NOTHROW { return i < other.i; }
-        inline bool operator<=(const iterator& other) const Q_DECL_NOTHROW { return i <= other.i; }
-        inline bool operator>(const iterator& other) const Q_DECL_NOTHROW { return i > other.i; }
-        inline bool operator>=(const iterator& other) const Q_DECL_NOTHROW { return i >= other.i; }
+        inline bool operator==(const iterator &o) const noexcept { return i == o.i; }
+        inline bool operator!=(const iterator &o) const noexcept { return i != o.i; }
+        inline bool operator<(const iterator& other) const noexcept { return i < other.i; }
+        inline bool operator<=(const iterator& other) const noexcept { return i <= other.i; }
+        inline bool operator>(const iterator& other) const noexcept { return i > other.i; }
+        inline bool operator>=(const iterator& other) const noexcept { return i >= other.i; }
 #ifndef QT_STRICT_ITERATORS
-        inline bool operator==(const const_iterator &o) const Q_DECL_NOTHROW
+        inline bool operator==(const const_iterator &o) const noexcept
             { return i == o.i; }
-        inline bool operator!=(const const_iterator &o) const Q_DECL_NOTHROW
+        inline bool operator!=(const const_iterator &o) const noexcept
             { return i != o.i; }
-        inline bool operator<(const const_iterator& other) const Q_DECL_NOTHROW
+        inline bool operator<(const const_iterator& other) const noexcept
             { return i < other.i; }
-        inline bool operator<=(const const_iterator& other) const Q_DECL_NOTHROW
+        inline bool operator<=(const const_iterator& other) const noexcept
             { return i <= other.i; }
-        inline bool operator>(const const_iterator& other) const Q_DECL_NOTHROW
+        inline bool operator>(const const_iterator& other) const noexcept
             { return i > other.i; }
-        inline bool operator>=(const const_iterator& other) const Q_DECL_NOTHROW
+        inline bool operator>=(const const_iterator& other) const noexcept
             { return i >= other.i; }
 #endif
         inline iterator &operator++() { ++i; return *this; }
@@ -296,27 +296,27 @@ public:
         typedef const T *pointer;
         typedef const T &reference;
 
-        inline const_iterator() Q_DECL_NOTHROW : i(nullptr) {}
-        inline const_iterator(Node *n) Q_DECL_NOTHROW : i(n) {}
+        inline const_iterator() noexcept : i(nullptr) {}
+        inline const_iterator(Node *n) noexcept : i(n) {}
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
         // can't remove it in Qt 5, since doing so would make the type trivial,
         // which changes the way it's passed to functions by value.
-        inline const_iterator(const const_iterator &o) Q_DECL_NOTHROW : i(o.i) {}
+        inline const_iterator(const const_iterator &o) noexcept : i(o.i) {}
 #endif
 #ifdef QT_STRICT_ITERATORS
-        inline explicit const_iterator(const iterator &o) Q_DECL_NOTHROW : i(o.i) {}
+        inline explicit const_iterator(const iterator &o) noexcept : i(o.i) {}
 #else
-        inline const_iterator(const iterator &o) Q_DECL_NOTHROW : i(o.i) {}
+        inline const_iterator(const iterator &o) noexcept : i(o.i) {}
 #endif
         inline const T &operator*() const { return i->t(); }
         inline const T *operator->() const { return &i->t(); }
         inline const T &operator[](difference_type j) const { return i[j].t(); }
-        inline bool operator==(const const_iterator &o) const Q_DECL_NOTHROW { return i == o.i; }
-        inline bool operator!=(const const_iterator &o) const Q_DECL_NOTHROW { return i != o.i; }
-        inline bool operator<(const const_iterator& other) const Q_DECL_NOTHROW { return i < other.i; }
-        inline bool operator<=(const const_iterator& other) const Q_DECL_NOTHROW { return i <= other.i; }
-        inline bool operator>(const const_iterator& other) const Q_DECL_NOTHROW { return i > other.i; }
-        inline bool operator>=(const const_iterator& other) const Q_DECL_NOTHROW { return i >= other.i; }
+        inline bool operator==(const const_iterator &o) const noexcept { return i == o.i; }
+        inline bool operator!=(const const_iterator &o) const noexcept { return i != o.i; }
+        inline bool operator<(const const_iterator& other) const noexcept { return i < other.i; }
+        inline bool operator<=(const const_iterator& other) const noexcept { return i <= other.i; }
+        inline bool operator>(const const_iterator& other) const noexcept { return i > other.i; }
+        inline bool operator>=(const const_iterator& other) const noexcept { return i >= other.i; }
         inline const_iterator &operator++() { ++i; return *this; }
         inline const_iterator operator++(int) { Node *n = i; ++i; return n; }
         inline const_iterator &operator--() { i--; return *this; }
@@ -334,19 +334,19 @@ public:
     typedef std::reverse_iterator<iterator> reverse_iterator;
     typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
     inline iterator begin() { detach(); return reinterpret_cast<Node *>(p.begin()); }
-    inline const_iterator begin() const Q_DECL_NOTHROW { return reinterpret_cast<Node *>(p.begin()); }
-    inline const_iterator cbegin() const Q_DECL_NOTHROW { return reinterpret_cast<Node *>(p.begin()); }
-    inline const_iterator constBegin() const Q_DECL_NOTHROW { return reinterpret_cast<Node *>(p.begin()); }
+    inline const_iterator begin() const noexcept { return reinterpret_cast<Node *>(p.begin()); }
+    inline const_iterator cbegin() const noexcept { return reinterpret_cast<Node *>(p.begin()); }
+    inline const_iterator constBegin() const noexcept { return reinterpret_cast<Node *>(p.begin()); }
     inline iterator end() { detach(); return reinterpret_cast<Node *>(p.end()); }
-    inline const_iterator end() const Q_DECL_NOTHROW { return reinterpret_cast<Node *>(p.end()); }
-    inline const_iterator cend() const Q_DECL_NOTHROW { return reinterpret_cast<Node *>(p.end()); }
-    inline const_iterator constEnd() const Q_DECL_NOTHROW { return reinterpret_cast<Node *>(p.end()); }
+    inline const_iterator end() const noexcept { return reinterpret_cast<Node *>(p.end()); }
+    inline const_iterator cend() const noexcept { return reinterpret_cast<Node *>(p.end()); }
+    inline const_iterator constEnd() const noexcept { return reinterpret_cast<Node *>(p.end()); }
     reverse_iterator rbegin() { return reverse_iterator(end()); }
     reverse_iterator rend() { return reverse_iterator(begin()); }
-    const_reverse_iterator rbegin() const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    const_reverse_iterator rend() const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
-    const_reverse_iterator crbegin() const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    const_reverse_iterator crend() const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
+    const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
+    const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
+    const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
+    const_reverse_iterator crend() const noexcept { return const_reverse_iterator(begin()); }
     iterator insert(iterator before, const T &t);
     iterator erase(iterator pos);
     iterator erase(iterator first, iterator last);
@@ -423,7 +423,7 @@ private:
     void node_copy(Node *from, Node *to, Node *src);
     void node_destruct(Node *from, Node *to);
 
-    bool isValidIterator(const iterator &i) const Q_DECL_NOTHROW
+    bool isValidIterator(const iterator &i) const noexcept
     {
         const std::less<const Node *> less = {};
         return !less(i.i, cbegin().i) && !less(cend().i, i.i);
diff --git a/src/corelib/tools/qlocale.cpp b/src/corelib/tools/qlocale.cpp
index ebb6c97975..9a3929c4a7 100644
--- a/src/corelib/tools/qlocale.cpp
+++ b/src/corelib/tools/qlocale.cpp
@@ -94,7 +94,7 @@ QT_BEGIN_INCLUDE_NAMESPACE
 #include "qlocale_data_p.h"
 QT_END_INCLUDE_NAMESPACE
 
-QLocale::Language QLocalePrivate::codeToLanguage(QStringView code) Q_DECL_NOTHROW
+QLocale::Language QLocalePrivate::codeToLanguage(QStringView code) noexcept
 {
     const auto len = code.size();
     if (len != 2 && len != 3)
@@ -138,7 +138,7 @@ QLocale::Language QLocalePrivate::codeToLanguage(QStringView code) Q_DECL_NOTHRO
     return QLocale::C;
 }
 
-QLocale::Script QLocalePrivate::codeToScript(QStringView code) Q_DECL_NOTHROW
+QLocale::Script QLocalePrivate::codeToScript(QStringView code) noexcept
 {
     const auto len = code.size();
     if (len != 4)
@@ -158,7 +158,7 @@ QLocale::Script QLocalePrivate::codeToScript(QStringView code) Q_DECL_NOTHROW
     return QLocale::AnyScript;
 }
 
-QLocale::Country QLocalePrivate::codeToCountry(QStringView code) Q_DECL_NOTHROW
+QLocale::Country QLocalePrivate::codeToCountry(QStringView code) noexcept
 {
     const auto len = code.size();
     if (len != 2 && len != 3)
@@ -982,7 +982,7 @@ bool QLocale::operator!=(const QLocale &other) const
     Returns the hash value for \a key, using
     \a seed to seed the calculation.
 */
-uint qHash(const QLocale &key, uint seed) Q_DECL_NOTHROW
+uint qHash(const QLocale &key, uint seed) noexcept
 {
     QtPrivate::QHashCombine hash;
     seed = hash(seed, key.d->m_data);
diff --git a/src/corelib/tools/qlocale.h b/src/corelib/tools/qlocale.h
index 2b4f131552..cb462db770 100644
--- a/src/corelib/tools/qlocale.h
+++ b/src/corelib/tools/qlocale.h
@@ -59,7 +59,7 @@ class QTextStreamPrivate;
 
 class QLocalePrivate;
 
-Q_CORE_EXPORT uint qHash(const QLocale &key, uint seed = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT uint qHash(const QLocale &key, uint seed = 0) noexcept;
 
 class Q_CORE_EXPORT QLocale
 {
@@ -940,12 +940,12 @@ public:
     QLocale(Language language, Script script, Country country);
     QLocale(const QLocale &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QLocale &operator=(QLocale &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QLocale &operator=(QLocale &&other) noexcept { swap(other); return *this; }
 #endif
     QLocale &operator=(const QLocale &other);
     ~QLocale();
 
-    void swap(QLocale &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    void swap(QLocale &other) noexcept { qSwap(d, other.d); }
 
     Language language() const;
     Script script() const;
@@ -1108,7 +1108,7 @@ private:
     QLocale(QLocalePrivate &dd);
     friend class QLocalePrivate;
     friend class QSystemLocale;
-    friend Q_CORE_EXPORT uint qHash(const QLocale &key, uint seed) Q_DECL_NOTHROW;
+    friend Q_CORE_EXPORT uint qHash(const QLocale &key, uint seed) noexcept;
 
     QSharedDataPointer<QLocalePrivate> d;
 };
diff --git a/src/corelib/tools/qlocale_p.h b/src/corelib/tools/qlocale_p.h
index 5edeed1954..de973d5eac 100644
--- a/src/corelib/tools/qlocale_p.h
+++ b/src/corelib/tools/qlocale_p.h
@@ -365,9 +365,9 @@ public:
     static QLatin1String languageToCode(QLocale::Language language);
     static QLatin1String scriptToCode(QLocale::Script script);
     static QLatin1String countryToCode(QLocale::Country country);
-    static QLocale::Language codeToLanguage(QStringView code) Q_DECL_NOTHROW;
-    static QLocale::Script codeToScript(QStringView code) Q_DECL_NOTHROW;
-    static QLocale::Country codeToCountry(QStringView code) Q_DECL_NOTHROW;
+    static QLocale::Language codeToLanguage(QStringView code) noexcept;
+    static QLocale::Script codeToScript(QStringView code) noexcept;
+    static QLocale::Country codeToCountry(QStringView code) noexcept;
     static void getLangAndCountry(const QString &name, QLocale::Language &lang,
                                   QLocale::Script &script, QLocale::Country &cntry);
 
diff --git a/src/corelib/tools/qmap.h b/src/corelib/tools/qmap.h
index 1cf9299e26..103124f4ad 100644
--- a/src/corelib/tools/qmap.h
+++ b/src/corelib/tools/qmap.h
@@ -100,10 +100,10 @@ struct Q_CORE_EXPORT QMapNodeBase
 
     template <typename T>
     static typename std::enable_if<QTypeInfo<T>::isComplex>::type
-    callDestructorIfNecessary(T &t) Q_DECL_NOTHROW { Q_UNUSED(t); t.~T(); } // Q_UNUSED: silence MSVC unused 't' warning
+    callDestructorIfNecessary(T &t) noexcept { Q_UNUSED(t); t.~T(); } // Q_UNUSED: silence MSVC unused 't' warning
     template <typename T>
     static typename std::enable_if<!QTypeInfo<T>::isComplex>::type
-    callDestructorIfNecessary(T &) Q_DECL_NOTHROW {}
+    callDestructorIfNecessary(T &) noexcept {}
 };
 
 template <class Key, class T>
@@ -325,7 +325,7 @@ class QMap
     QMapData<Key, T> *d;
 
 public:
-    inline QMap() Q_DECL_NOTHROW : d(static_cast<QMapData<Key, T> *>(const_cast<QMapDataBase *>(&QMapDataBase::shared_null))) { }
+    inline QMap() noexcept : d(static_cast<QMapData<Key, T> *>(const_cast<QMapDataBase *>(&QMapDataBase::shared_null))) { }
 #ifdef Q_COMPILER_INITIALIZER_LISTS
     inline QMap(std::initializer_list<std::pair<Key,T> > list)
         : d(static_cast<QMapData<Key, T> *>(const_cast<QMapDataBase *>(&QMapDataBase::shared_null)))
@@ -340,17 +340,17 @@ public:
 
     QMap<Key, T> &operator=(const QMap<Key, T> &other);
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QMap(QMap<Key, T> &&other) Q_DECL_NOTHROW
+    inline QMap(QMap<Key, T> &&other) noexcept
         : d(other.d)
     {
         other.d = static_cast<QMapData<Key, T> *>(
                 const_cast<QMapDataBase *>(&QMapDataBase::shared_null));
     }
 
-    inline QMap<Key, T> &operator=(QMap<Key, T> &&other) Q_DECL_NOTHROW
+    inline QMap<Key, T> &operator=(QMap<Key, T> &&other) noexcept
     { QMap moved(std::move(other)); swap(moved); return *this; }
 #endif
-    inline void swap(QMap<Key, T> &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    inline void swap(QMap<Key, T> &other) noexcept { qSwap(d, other.d); }
     explicit QMap(const typename std::map<Key, T> &other);
     std::map<Key, T> toStdMap() const;
 
@@ -1187,7 +1187,7 @@ template <class Key, class T>
 class QMultiMap : public QMap<Key, T>
 {
 public:
-    QMultiMap() Q_DECL_NOTHROW {}
+    QMultiMap() noexcept {}
 #ifdef Q_COMPILER_INITIALIZER_LISTS
     inline QMultiMap(std::initializer_list<std::pair<Key,T> > list)
     {
@@ -1197,9 +1197,9 @@ public:
 #endif
     QMultiMap(const QMap<Key, T> &other) : QMap<Key, T>(other) {}
 #ifdef Q_COMPILER_RVALUE_REFS
-    QMultiMap(QMap<Key, T> &&other) Q_DECL_NOTHROW : QMap<Key, T>(std::move(other)) {}
+    QMultiMap(QMap<Key, T> &&other) noexcept : QMap<Key, T>(std::move(other)) {}
 #endif
-    void swap(QMultiMap<Key, T> &other) Q_DECL_NOTHROW { QMap<Key, T>::swap(other); }
+    void swap(QMultiMap<Key, T> &other) noexcept { QMap<Key, T>::swap(other); }
 
     inline typename QMap<Key, T>::iterator replace(const Key &key, const T &value)
     { return QMap<Key, T>::insert(key, value); }
diff --git a/src/corelib/tools/qmargins.h b/src/corelib/tools/qmargins.h
index 0c73235d26..447037daaa 100644
--- a/src/corelib/tools/qmargins.h
+++ b/src/corelib/tools/qmargins.h
@@ -51,28 +51,28 @@ QT_BEGIN_NAMESPACE
 class QMargins
 {
 public:
-    Q_DECL_CONSTEXPR QMargins() Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QMargins(int left, int top, int right, int bottom) Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR bool isNull() const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR int left() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR int top() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR int right() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR int bottom() const Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR void setLeft(int left) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR void setTop(int top) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR void setRight(int right) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR void setBottom(int bottom) Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR QMargins &operator+=(const QMargins &margins) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR QMargins &operator-=(const QMargins &margins) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR QMargins &operator+=(int) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR QMargins &operator-=(int) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR QMargins &operator*=(int) Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR QMargins() noexcept;
+    Q_DECL_CONSTEXPR QMargins(int left, int top, int right, int bottom) noexcept;
+
+    Q_DECL_CONSTEXPR bool isNull() const noexcept;
+
+    Q_DECL_CONSTEXPR int left() const noexcept;
+    Q_DECL_CONSTEXPR int top() const noexcept;
+    Q_DECL_CONSTEXPR int right() const noexcept;
+    Q_DECL_CONSTEXPR int bottom() const noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR void setLeft(int left) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR void setTop(int top) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR void setRight(int right) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR void setBottom(int bottom) noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR QMargins &operator+=(const QMargins &margins) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR QMargins &operator-=(const QMargins &margins) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR QMargins &operator+=(int) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR QMargins &operator-=(int) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR QMargins &operator*=(int) noexcept;
     Q_DECL_RELAXED_CONSTEXPR QMargins &operator/=(int);
-    Q_DECL_RELAXED_CONSTEXPR QMargins &operator*=(qreal) Q_DECL_NOTHROW;
+    Q_DECL_RELAXED_CONSTEXPR QMargins &operator*=(qreal) noexcept;
     Q_DECL_RELAXED_CONSTEXPR QMargins &operator/=(qreal);
 
 private:
@@ -81,8 +81,8 @@ private:
     int m_right;
     int m_bottom;
 
-    friend Q_DECL_CONSTEXPR inline bool operator==(const QMargins &, const QMargins &) Q_DECL_NOTHROW;
-    friend Q_DECL_CONSTEXPR inline bool operator!=(const QMargins &, const QMargins &) Q_DECL_NOTHROW;
+    friend Q_DECL_CONSTEXPR inline bool operator==(const QMargins &, const QMargins &) noexcept;
+    friend Q_DECL_CONSTEXPR inline bool operator!=(const QMargins &, const QMargins &) noexcept;
 };
 
 Q_DECLARE_TYPEINFO(QMargins, Q_MOVABLE_TYPE);
@@ -99,40 +99,40 @@ Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QMargins &);
   QMargins inline functions
  *****************************************************************************/
 
-Q_DECL_CONSTEXPR inline QMargins::QMargins() Q_DECL_NOTHROW : m_left(0), m_top(0), m_right(0), m_bottom(0) {}
+Q_DECL_CONSTEXPR inline QMargins::QMargins() noexcept : m_left(0), m_top(0), m_right(0), m_bottom(0) {}
 
-Q_DECL_CONSTEXPR inline QMargins::QMargins(int aleft, int atop, int aright, int abottom) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins::QMargins(int aleft, int atop, int aright, int abottom) noexcept
     : m_left(aleft), m_top(atop), m_right(aright), m_bottom(abottom) {}
 
-Q_DECL_CONSTEXPR inline bool QMargins::isNull() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QMargins::isNull() const noexcept
 { return m_left==0 && m_top==0 && m_right==0 && m_bottom==0; }
 
-Q_DECL_CONSTEXPR inline int QMargins::left() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QMargins::left() const noexcept
 { return m_left; }
 
-Q_DECL_CONSTEXPR inline int QMargins::top() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QMargins::top() const noexcept
 { return m_top; }
 
-Q_DECL_CONSTEXPR inline int QMargins::right() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QMargins::right() const noexcept
 { return m_right; }
 
-Q_DECL_CONSTEXPR inline int QMargins::bottom() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QMargins::bottom() const noexcept
 { return m_bottom; }
 
 
-Q_DECL_RELAXED_CONSTEXPR inline void QMargins::setLeft(int aleft) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QMargins::setLeft(int aleft) noexcept
 { m_left = aleft; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QMargins::setTop(int atop) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QMargins::setTop(int atop) noexcept
 { m_top = atop; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QMargins::setRight(int aright) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QMargins::setRight(int aright) noexcept
 { m_right = aright; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QMargins::setBottom(int abottom) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QMargins::setBottom(int abottom) noexcept
 { m_bottom = abottom; }
 
-Q_DECL_CONSTEXPR inline bool operator==(const QMargins &m1, const QMargins &m2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator==(const QMargins &m1, const QMargins &m2) noexcept
 {
     return
             m1.m_left == m2.m_left &&
@@ -141,7 +141,7 @@ Q_DECL_CONSTEXPR inline bool operator==(const QMargins &m1, const QMargins &m2)
             m1.m_bottom == m2.m_bottom;
 }
 
-Q_DECL_CONSTEXPR inline bool operator!=(const QMargins &m1, const QMargins &m2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator!=(const QMargins &m1, const QMargins &m2) noexcept
 {
     return
             m1.m_left != m2.m_left ||
@@ -150,55 +150,55 @@ Q_DECL_CONSTEXPR inline bool operator!=(const QMargins &m1, const QMargins &m2)
             m1.m_bottom != m2.m_bottom;
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator+(const QMargins &m1, const QMargins &m2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator+(const QMargins &m1, const QMargins &m2) noexcept
 {
     return QMargins(m1.left() + m2.left(), m1.top() + m2.top(),
                     m1.right() + m2.right(), m1.bottom() + m2.bottom());
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator-(const QMargins &m1, const QMargins &m2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator-(const QMargins &m1, const QMargins &m2) noexcept
 {
     return QMargins(m1.left() - m2.left(), m1.top() - m2.top(),
                     m1.right() - m2.right(), m1.bottom() - m2.bottom());
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator+(const QMargins &lhs, int rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator+(const QMargins &lhs, int rhs) noexcept
 {
     return QMargins(lhs.left() + rhs, lhs.top() + rhs,
                     lhs.right() + rhs, lhs.bottom() + rhs);
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator+(int lhs, const QMargins &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator+(int lhs, const QMargins &rhs) noexcept
 {
     return QMargins(rhs.left() + lhs, rhs.top() + lhs,
                     rhs.right() + lhs, rhs.bottom() + lhs);
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator-(const QMargins &lhs, int rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator-(const QMargins &lhs, int rhs) noexcept
 {
     return QMargins(lhs.left() - rhs, lhs.top() - rhs,
                     lhs.right() - rhs, lhs.bottom() - rhs);
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator*(const QMargins &margins, int factor) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator*(const QMargins &margins, int factor) noexcept
 {
     return QMargins(margins.left() * factor, margins.top() * factor,
                     margins.right() * factor, margins.bottom() * factor);
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator*(int factor, const QMargins &margins) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator*(int factor, const QMargins &margins) noexcept
 {
     return QMargins(margins.left() * factor, margins.top() * factor,
                     margins.right() * factor, margins.bottom() * factor);
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator*(const QMargins &margins, qreal factor) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator*(const QMargins &margins, qreal factor) noexcept
 {
     return QMargins(qRound(margins.left() * factor), qRound(margins.top() * factor),
                     qRound(margins.right() * factor), qRound(margins.bottom() * factor));
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator*(qreal factor, const QMargins &margins) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator*(qreal factor, const QMargins &margins) noexcept
 {
     return QMargins(qRound(margins.left() * factor), qRound(margins.top() * factor),
                     qRound(margins.right() * factor), qRound(margins.bottom() * factor));
@@ -216,17 +216,17 @@ Q_DECL_CONSTEXPR inline QMargins operator/(const QMargins &margins, qreal diviso
                     qRound(margins.right() / divisor), qRound(margins.bottom() / divisor));
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator+=(const QMargins &margins) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator+=(const QMargins &margins) noexcept
 {
     return *this = *this + margins;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator-=(const QMargins &margins) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator-=(const QMargins &margins) noexcept
 {
     return *this = *this - margins;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator+=(int margin) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator+=(int margin) noexcept
 {
     m_left += margin;
     m_top += margin;
@@ -235,7 +235,7 @@ Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator+=(int margin) Q_DEC
     return *this;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator-=(int margin) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator-=(int margin) noexcept
 {
     m_left -= margin;
     m_top -= margin;
@@ -244,7 +244,7 @@ Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator-=(int margin) Q_DEC
     return *this;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator*=(int factor) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator*=(int factor) noexcept
 {
     return *this = *this * factor;
 }
@@ -254,7 +254,7 @@ Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator/=(int divisor)
     return *this = *this / divisor;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator*=(qreal factor) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator*=(qreal factor) noexcept
 {
     return *this = *this * factor;
 }
@@ -264,12 +264,12 @@ Q_DECL_RELAXED_CONSTEXPR inline QMargins &QMargins::operator/=(qreal divisor)
     return *this = *this / divisor;
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator+(const QMargins &margins) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator+(const QMargins &margins) noexcept
 {
     return margins;
 }
 
-Q_DECL_CONSTEXPR inline QMargins operator-(const QMargins &margins) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins operator-(const QMargins &margins) noexcept
 {
     return QMargins(-margins.left(), -margins.top(), -margins.right(), -margins.bottom());
 }
@@ -285,30 +285,30 @@ Q_CORE_EXPORT QDebug operator<<(QDebug, const QMargins &);
 class QMarginsF
 {
 public:
-    Q_DECL_CONSTEXPR QMarginsF() Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QMarginsF(qreal left, qreal top, qreal right, qreal bottom) Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QMarginsF(const QMargins &margins) Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR bool isNull() const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR qreal left() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR qreal top() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR qreal right() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR qreal bottom() const Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR void setLeft(qreal left) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR void setTop(qreal top) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR void setRight(qreal right) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR void setBottom(qreal bottom) Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator+=(const QMarginsF &margins) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator-=(const QMarginsF &margins) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator+=(qreal addend) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator-=(qreal subtrahend) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator*=(qreal factor) Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR QMarginsF() noexcept;
+    Q_DECL_CONSTEXPR QMarginsF(qreal left, qreal top, qreal right, qreal bottom) noexcept;
+    Q_DECL_CONSTEXPR QMarginsF(const QMargins &margins) noexcept;
+
+    Q_DECL_CONSTEXPR bool isNull() const noexcept;
+
+    Q_DECL_CONSTEXPR qreal left() const noexcept;
+    Q_DECL_CONSTEXPR qreal top() const noexcept;
+    Q_DECL_CONSTEXPR qreal right() const noexcept;
+    Q_DECL_CONSTEXPR qreal bottom() const noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR void setLeft(qreal left) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR void setTop(qreal top) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR void setRight(qreal right) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR void setBottom(qreal bottom) noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator+=(const QMarginsF &margins) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator-=(const QMarginsF &margins) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator+=(qreal addend) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator-=(qreal subtrahend) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator*=(qreal factor) noexcept;
     Q_DECL_RELAXED_CONSTEXPR QMarginsF &operator/=(qreal divisor);
 
-    Q_DECL_CONSTEXPR inline QMargins toMargins() const Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR inline QMargins toMargins() const noexcept;
 
 private:
     qreal m_left;
@@ -332,44 +332,44 @@ Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QMarginsF &);
   QMarginsF inline functions
  *****************************************************************************/
 
-Q_DECL_CONSTEXPR inline QMarginsF::QMarginsF() Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF::QMarginsF() noexcept
     : m_left(0), m_top(0), m_right(0), m_bottom(0) {}
 
-Q_DECL_CONSTEXPR inline QMarginsF::QMarginsF(qreal aleft, qreal atop, qreal aright, qreal abottom) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF::QMarginsF(qreal aleft, qreal atop, qreal aright, qreal abottom) noexcept
     : m_left(aleft), m_top(atop), m_right(aright), m_bottom(abottom) {}
 
-Q_DECL_CONSTEXPR inline QMarginsF::QMarginsF(const QMargins &margins) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF::QMarginsF(const QMargins &margins) noexcept
     : m_left(margins.left()), m_top(margins.top()), m_right(margins.right()), m_bottom(margins.bottom()) {}
 
-Q_DECL_CONSTEXPR inline bool QMarginsF::isNull() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QMarginsF::isNull() const noexcept
 { return qFuzzyIsNull(m_left) && qFuzzyIsNull(m_top) && qFuzzyIsNull(m_right) && qFuzzyIsNull(m_bottom); }
 
-Q_DECL_CONSTEXPR inline qreal QMarginsF::left() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline qreal QMarginsF::left() const noexcept
 { return m_left; }
 
-Q_DECL_CONSTEXPR inline qreal QMarginsF::top() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline qreal QMarginsF::top() const noexcept
 { return m_top; }
 
-Q_DECL_CONSTEXPR inline qreal QMarginsF::right() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline qreal QMarginsF::right() const noexcept
 { return m_right; }
 
-Q_DECL_CONSTEXPR inline qreal QMarginsF::bottom() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline qreal QMarginsF::bottom() const noexcept
 { return m_bottom; }
 
 
-Q_DECL_RELAXED_CONSTEXPR inline void QMarginsF::setLeft(qreal aleft) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QMarginsF::setLeft(qreal aleft) noexcept
 { m_left = aleft; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QMarginsF::setTop(qreal atop) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QMarginsF::setTop(qreal atop) noexcept
 { m_top = atop; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QMarginsF::setRight(qreal aright) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QMarginsF::setRight(qreal aright) noexcept
 { m_right = aright; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QMarginsF::setBottom(qreal abottom) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QMarginsF::setBottom(qreal abottom) noexcept
 { m_bottom = abottom; }
 
-Q_DECL_CONSTEXPR inline bool operator==(const QMarginsF &lhs, const QMarginsF &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator==(const QMarginsF &lhs, const QMarginsF &rhs) noexcept
 {
     return qFuzzyCompare(lhs.left(), rhs.left())
            && qFuzzyCompare(lhs.top(), rhs.top())
@@ -377,48 +377,48 @@ Q_DECL_CONSTEXPR inline bool operator==(const QMarginsF &lhs, const QMarginsF &r
            && qFuzzyCompare(lhs.bottom(), rhs.bottom());
 }
 
-Q_DECL_CONSTEXPR inline bool operator!=(const QMarginsF &lhs, const QMarginsF &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator!=(const QMarginsF &lhs, const QMarginsF &rhs) noexcept
 {
     return !operator==(lhs, rhs);
 }
 
-Q_DECL_CONSTEXPR inline QMarginsF operator+(const QMarginsF &lhs, const QMarginsF &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF operator+(const QMarginsF &lhs, const QMarginsF &rhs) noexcept
 {
     return QMarginsF(lhs.left() + rhs.left(), lhs.top() + rhs.top(),
                      lhs.right() + rhs.right(), lhs.bottom() + rhs.bottom());
 }
 
-Q_DECL_CONSTEXPR inline QMarginsF operator-(const QMarginsF &lhs, const QMarginsF &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF operator-(const QMarginsF &lhs, const QMarginsF &rhs) noexcept
 {
     return QMarginsF(lhs.left() - rhs.left(), lhs.top() - rhs.top(),
                      lhs.right() - rhs.right(), lhs.bottom() - rhs.bottom());
 }
 
-Q_DECL_CONSTEXPR inline QMarginsF operator+(const QMarginsF &lhs, qreal rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF operator+(const QMarginsF &lhs, qreal rhs) noexcept
 {
     return QMarginsF(lhs.left() + rhs, lhs.top() + rhs,
                      lhs.right() + rhs, lhs.bottom() + rhs);
 }
 
-Q_DECL_CONSTEXPR inline QMarginsF operator+(qreal lhs, const QMarginsF &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF operator+(qreal lhs, const QMarginsF &rhs) noexcept
 {
     return QMarginsF(rhs.left() + lhs, rhs.top() + lhs,
                      rhs.right() + lhs, rhs.bottom() + lhs);
 }
 
-Q_DECL_CONSTEXPR inline QMarginsF operator-(const QMarginsF &lhs, qreal rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF operator-(const QMarginsF &lhs, qreal rhs) noexcept
 {
     return QMarginsF(lhs.left() - rhs, lhs.top() - rhs,
                      lhs.right() - rhs, lhs.bottom() - rhs);
 }
 
-Q_DECL_CONSTEXPR inline QMarginsF operator*(const QMarginsF &lhs, qreal rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF operator*(const QMarginsF &lhs, qreal rhs) noexcept
 {
     return QMarginsF(lhs.left() * rhs, lhs.top() * rhs,
                      lhs.right() * rhs, lhs.bottom() * rhs);
 }
 
-Q_DECL_CONSTEXPR inline QMarginsF operator*(qreal lhs, const QMarginsF &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF operator*(qreal lhs, const QMarginsF &rhs) noexcept
 {
     return QMarginsF(rhs.left() * lhs, rhs.top() * lhs,
                      rhs.right() * lhs, rhs.bottom() * lhs);
@@ -430,17 +430,17 @@ Q_DECL_CONSTEXPR inline QMarginsF operator/(const QMarginsF &lhs, qreal divisor)
                      lhs.right() / divisor, lhs.bottom() / divisor);
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator+=(const QMarginsF &margins) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator+=(const QMarginsF &margins) noexcept
 {
     return *this = *this + margins;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator-=(const QMarginsF &margins) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator-=(const QMarginsF &margins) noexcept
 {
     return *this = *this - margins;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator+=(qreal addend) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator+=(qreal addend) noexcept
 {
     m_left += addend;
     m_top += addend;
@@ -449,7 +449,7 @@ Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator+=(qreal addend) Q
     return *this;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator-=(qreal subtrahend) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator-=(qreal subtrahend) noexcept
 {
     m_left -= subtrahend;
     m_top -= subtrahend;
@@ -458,7 +458,7 @@ Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator-=(qreal subtrahen
     return *this;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator*=(qreal factor) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator*=(qreal factor) noexcept
 {
     return *this = *this * factor;
 }
@@ -468,17 +468,17 @@ Q_DECL_RELAXED_CONSTEXPR inline QMarginsF &QMarginsF::operator/=(qreal divisor)
     return *this = *this / divisor;
 }
 
-Q_DECL_CONSTEXPR inline QMarginsF operator+(const QMarginsF &margins) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF operator+(const QMarginsF &margins) noexcept
 {
     return margins;
 }
 
-Q_DECL_CONSTEXPR inline QMarginsF operator-(const QMarginsF &margins) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMarginsF operator-(const QMarginsF &margins) noexcept
 {
     return QMarginsF(-margins.left(), -margins.top(), -margins.right(), -margins.bottom());
 }
 
-Q_DECL_CONSTEXPR inline QMargins QMarginsF::toMargins() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QMargins QMarginsF::toMargins() const noexcept
 {
     return QMargins(qRound(m_left), qRound(m_top), qRound(m_right), qRound(m_bottom));
 }
diff --git a/src/corelib/tools/qpoint.h b/src/corelib/tools/qpoint.h
index d7323f7707..34df673b93 100644
--- a/src/corelib/tools/qpoint.h
+++ b/src/corelib/tools/qpoint.h
@@ -94,7 +94,7 @@ public:
     friend Q_DECL_CONSTEXPR inline const QPoint operator/(const QPoint &, qreal);
 
 #if defined(Q_OS_DARWIN) || defined(Q_QDOC)
-    Q_REQUIRED_RESULT CGPoint toCGPoint() const Q_DECL_NOTHROW;
+    Q_REQUIRED_RESULT CGPoint toCGPoint() const noexcept;
 #endif
 
 private:
@@ -256,8 +256,8 @@ public:
     Q_DECL_CONSTEXPR QPoint toPoint() const;
 
 #if defined(Q_OS_DARWIN) || defined(Q_QDOC)
-    Q_REQUIRED_RESULT static QPointF fromCGPoint(CGPoint point) Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT CGPoint toCGPoint() const Q_DECL_NOTHROW;
+    Q_REQUIRED_RESULT static QPointF fromCGPoint(CGPoint point) noexcept;
+    Q_REQUIRED_RESULT CGPoint toCGPoint() const noexcept;
 #endif
 
 private:
diff --git a/src/corelib/tools/qqueue.h b/src/corelib/tools/qqueue.h
index b55f210577..16229759ee 100644
--- a/src/corelib/tools/qqueue.h
+++ b/src/corelib/tools/qqueue.h
@@ -50,7 +50,7 @@ class QQueue : public QList<T>
 {
 public:
     // compiler-generated special member functions are fine!
-    inline void swap(QQueue<T> &other) Q_DECL_NOTHROW { QList<T>::swap(other); } // prevent QList<->QQueue swaps
+    inline void swap(QQueue<T> &other) noexcept { QList<T>::swap(other); } // prevent QList<->QQueue swaps
 #ifndef Q_QDOC
     // bring in QList::swap(int, int). We cannot say using QList<T>::swap,
     // because we don't want to make swap(QList&) available.
diff --git a/src/corelib/tools/qrect.cpp b/src/corelib/tools/qrect.cpp
index 6e51deebea..d622f92530 100644
--- a/src/corelib/tools/qrect.cpp
+++ b/src/corelib/tools/qrect.cpp
@@ -300,7 +300,7 @@ QT_BEGIN_NAMESPACE
     \sa isValid(), isEmpty()
 */
 
-QRect QRect::normalized() const Q_DECL_NOTHROW
+QRect QRect::normalized() const noexcept
 {
     QRect r;
     if (x2 < x1 - 1) {                                // swap bad x values
@@ -820,7 +820,7 @@ QRect QRect::normalized() const Q_DECL_NOTHROW
     \sa intersects()
 */
 
-bool QRect::contains(const QPoint &p, bool proper) const Q_DECL_NOTHROW
+bool QRect::contains(const QPoint &p, bool proper) const noexcept
 {
     int l, r;
     if (x2 < x1 - 1) {
@@ -884,7 +884,7 @@ bool QRect::contains(const QPoint &p, bool proper) const Q_DECL_NOTHROW
     rectangle (not on the edge).
 */
 
-bool QRect::contains(const QRect &r, bool proper) const Q_DECL_NOTHROW
+bool QRect::contains(const QRect &r, bool proper) const noexcept
 {
     if (isNull() || r.isNull())
         return false;
@@ -962,7 +962,7 @@ bool QRect::contains(const QRect &r, bool proper) const Q_DECL_NOTHROW
     \sa operator|=(), united()
 */
 
-QRect QRect::operator|(const QRect &r) const Q_DECL_NOTHROW
+QRect QRect::operator|(const QRect &r) const noexcept
 {
     if (isNull())
         return r;
@@ -1033,7 +1033,7 @@ QRect QRect::operator|(const QRect &r) const Q_DECL_NOTHROW
     \sa operator&=(), intersected()
 */
 
-QRect QRect::operator&(const QRect &r) const Q_DECL_NOTHROW
+QRect QRect::operator&(const QRect &r) const noexcept
 {
     if (isNull() || r.isNull())
         return QRect();
@@ -1112,7 +1112,7 @@ QRect QRect::operator&(const QRect &r) const Q_DECL_NOTHROW
     \sa contains()
 */
 
-bool QRect::intersects(const QRect &r) const Q_DECL_NOTHROW
+bool QRect::intersects(const QRect &r) const noexcept
 {
     if (isNull() || r.isNull())
         return false;
@@ -1540,7 +1540,7 @@ QDebug operator<<(QDebug dbg, const QRect &r)
     \sa isValid(), isEmpty()
 */
 
-QRectF QRectF::normalized() const Q_DECL_NOTHROW
+QRectF QRectF::normalized() const noexcept
 {
     QRectF r = *this;
     if (r.w < 0) {
@@ -1964,7 +1964,7 @@ QRectF QRectF::normalized() const Q_DECL_NOTHROW
     \sa intersects()
 */
 
-bool QRectF::contains(const QPointF &p) const Q_DECL_NOTHROW
+bool QRectF::contains(const QPointF &p) const noexcept
 {
     qreal l = xp;
     qreal r = xp;
@@ -2010,7 +2010,7 @@ bool QRectF::contains(const QPointF &p) const Q_DECL_NOTHROW
     otherwise returns \c false.
 */
 
-bool QRectF::contains(const QRectF &r) const Q_DECL_NOTHROW
+bool QRectF::contains(const QRectF &r) const noexcept
 {
     qreal l1 = xp;
     qreal r1 = xp;
@@ -2148,7 +2148,7 @@ bool QRectF::contains(const QRectF &r) const Q_DECL_NOTHROW
     \sa united(), operator|=()
 */
 
-QRectF QRectF::operator|(const QRectF &r) const Q_DECL_NOTHROW
+QRectF QRectF::operator|(const QRectF &r) const noexcept
 {
     if (isNull())
         return r;
@@ -2217,7 +2217,7 @@ QRectF QRectF::operator|(const QRectF &r) const Q_DECL_NOTHROW
     \sa operator&=(), intersected()
 */
 
-QRectF QRectF::operator&(const QRectF &r) const Q_DECL_NOTHROW
+QRectF QRectF::operator&(const QRectF &r) const noexcept
 {
     qreal l1 = xp;
     qreal r1 = xp;
@@ -2302,7 +2302,7 @@ QRectF QRectF::operator&(const QRectF &r) const Q_DECL_NOTHROW
     \sa contains()
 */
 
-bool QRectF::intersects(const QRectF &r) const Q_DECL_NOTHROW
+bool QRectF::intersects(const QRectF &r) const noexcept
 {
     qreal l1 = xp;
     qreal r1 = xp;
@@ -2369,7 +2369,7 @@ bool QRectF::intersects(const QRectF &r) const Q_DECL_NOTHROW
     \sa toRect()
 */
 
-QRect QRectF::toAlignedRect() const Q_DECL_NOTHROW
+QRect QRectF::toAlignedRect() const noexcept
 {
     int xmin = int(qFloor(xp));
     int xmax = int(qCeil(xp + w));
diff --git a/src/corelib/tools/qrect.h b/src/corelib/tools/qrect.h
index 3b40055b5a..7aa2312f38 100644
--- a/src/corelib/tools/qrect.h
+++ b/src/corelib/tools/qrect.h
@@ -57,104 +57,104 @@ QT_BEGIN_NAMESPACE
 class Q_CORE_EXPORT QRect
 {
 public:
-    Q_DECL_CONSTEXPR QRect() Q_DECL_NOTHROW : x1(0), y1(0), x2(-1), y2(-1) {}
-    Q_DECL_CONSTEXPR QRect(const QPoint &topleft, const QPoint &bottomright) Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QRect(const QPoint &topleft, const QSize &size) Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QRect(int left, int top, int width, int height) Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline bool isNull() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline bool isEmpty() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline bool isValid() const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline int left() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline int top() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline int right() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline int bottom() const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT QRect normalized() const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline int x() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline int y() const Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setLeft(int pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setTop(int pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setRight(int pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setBottom(int pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setX(int x) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setY(int y) Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline void setTopLeft(const QPoint &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setBottomRight(const QPoint &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setTopRight(const QPoint &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setBottomLeft(const QPoint &p) Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline QPoint topLeft() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline QPoint bottomRight() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline QPoint topRight() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline QPoint bottomLeft() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline QPoint center() const Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline void moveLeft(int pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveTop(int pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveRight(int pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveBottom(int pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveTopLeft(const QPoint &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveBottomRight(const QPoint &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveTopRight(const QPoint &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveBottomLeft(const QPoint &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveCenter(const QPoint &p) Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline void translate(int dx, int dy) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void translate(const QPoint &p) Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRect translated(int dx, int dy) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRect translated(const QPoint &p) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRect transposed() const Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline void moveTo(int x, int t) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveTo(const QPoint &p) Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline void setRect(int x, int y, int w, int h) Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR QRect() noexcept : x1(0), y1(0), x2(-1), y2(-1) {}
+    Q_DECL_CONSTEXPR QRect(const QPoint &topleft, const QPoint &bottomright) noexcept;
+    Q_DECL_CONSTEXPR QRect(const QPoint &topleft, const QSize &size) noexcept;
+    Q_DECL_CONSTEXPR QRect(int left, int top, int width, int height) noexcept;
+
+    Q_DECL_CONSTEXPR inline bool isNull() const noexcept;
+    Q_DECL_CONSTEXPR inline bool isEmpty() const noexcept;
+    Q_DECL_CONSTEXPR inline bool isValid() const noexcept;
+
+    Q_DECL_CONSTEXPR inline int left() const noexcept;
+    Q_DECL_CONSTEXPR inline int top() const noexcept;
+    Q_DECL_CONSTEXPR inline int right() const noexcept;
+    Q_DECL_CONSTEXPR inline int bottom() const noexcept;
+    Q_REQUIRED_RESULT QRect normalized() const noexcept;
+
+    Q_DECL_CONSTEXPR inline int x() const noexcept;
+    Q_DECL_CONSTEXPR inline int y() const noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setLeft(int pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setTop(int pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setRight(int pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setBottom(int pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setX(int x) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setY(int y) noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline void setTopLeft(const QPoint &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setBottomRight(const QPoint &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setTopRight(const QPoint &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setBottomLeft(const QPoint &p) noexcept;
+
+    Q_DECL_CONSTEXPR inline QPoint topLeft() const noexcept;
+    Q_DECL_CONSTEXPR inline QPoint bottomRight() const noexcept;
+    Q_DECL_CONSTEXPR inline QPoint topRight() const noexcept;
+    Q_DECL_CONSTEXPR inline QPoint bottomLeft() const noexcept;
+    Q_DECL_CONSTEXPR inline QPoint center() const noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline void moveLeft(int pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveTop(int pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveRight(int pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveBottom(int pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveTopLeft(const QPoint &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveBottomRight(const QPoint &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveTopRight(const QPoint &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveBottomLeft(const QPoint &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveCenter(const QPoint &p) noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline void translate(int dx, int dy) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void translate(const QPoint &p) noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRect translated(int dx, int dy) const noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRect translated(const QPoint &p) const noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRect transposed() const noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline void moveTo(int x, int t) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveTo(const QPoint &p) noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline void setRect(int x, int y, int w, int h) noexcept;
     Q_DECL_RELAXED_CONSTEXPR inline void getRect(int *x, int *y, int *w, int *h) const;
 
-    Q_DECL_RELAXED_CONSTEXPR inline void setCoords(int x1, int y1, int x2, int y2) Q_DECL_NOTHROW;
+    Q_DECL_RELAXED_CONSTEXPR inline void setCoords(int x1, int y1, int x2, int y2) noexcept;
     Q_DECL_RELAXED_CONSTEXPR inline void getCoords(int *x1, int *y1, int *x2, int *y2) const;
 
-    Q_DECL_RELAXED_CONSTEXPR inline void adjust(int x1, int y1, int x2, int y2) Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRect adjusted(int x1, int y1, int x2, int y2) const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline QSize size() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline int width() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline int height() const Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setWidth(int w) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setHeight(int h) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setSize(const QSize &s) Q_DECL_NOTHROW;
-
-    QRect operator|(const QRect &r) const Q_DECL_NOTHROW;
-    QRect operator&(const QRect &r) const Q_DECL_NOTHROW;
-    inline QRect& operator|=(const QRect &r) Q_DECL_NOTHROW;
-    inline QRect& operator&=(const QRect &r) Q_DECL_NOTHROW;
-
-    bool contains(const QRect &r, bool proper = false) const Q_DECL_NOTHROW;
-    bool contains(const QPoint &p, bool proper=false) const Q_DECL_NOTHROW;
-    inline bool contains(int x, int y) const Q_DECL_NOTHROW;
-    inline bool contains(int x, int y, bool proper) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT inline QRect united(const QRect &other) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT inline QRect intersected(const QRect &other) const Q_DECL_NOTHROW;
-    bool intersects(const QRect &r) const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline QRect marginsAdded(const QMargins &margins) const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline QRect marginsRemoved(const QMargins &margins) const Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline QRect &operator+=(const QMargins &margins) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline QRect &operator-=(const QMargins &margins) Q_DECL_NOTHROW;
+    Q_DECL_RELAXED_CONSTEXPR inline void adjust(int x1, int y1, int x2, int y2) noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRect adjusted(int x1, int y1, int x2, int y2) const noexcept;
+
+    Q_DECL_CONSTEXPR inline QSize size() const noexcept;
+    Q_DECL_CONSTEXPR inline int width() const noexcept;
+    Q_DECL_CONSTEXPR inline int height() const noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setWidth(int w) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setHeight(int h) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setSize(const QSize &s) noexcept;
+
+    QRect operator|(const QRect &r) const noexcept;
+    QRect operator&(const QRect &r) const noexcept;
+    inline QRect& operator|=(const QRect &r) noexcept;
+    inline QRect& operator&=(const QRect &r) noexcept;
+
+    bool contains(const QRect &r, bool proper = false) const noexcept;
+    bool contains(const QPoint &p, bool proper=false) const noexcept;
+    inline bool contains(int x, int y) const noexcept;
+    inline bool contains(int x, int y, bool proper) const noexcept;
+    Q_REQUIRED_RESULT inline QRect united(const QRect &other) const noexcept;
+    Q_REQUIRED_RESULT inline QRect intersected(const QRect &other) const noexcept;
+    bool intersects(const QRect &r) const noexcept;
+
+    Q_DECL_CONSTEXPR inline QRect marginsAdded(const QMargins &margins) const noexcept;
+    Q_DECL_CONSTEXPR inline QRect marginsRemoved(const QMargins &margins) const noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline QRect &operator+=(const QMargins &margins) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline QRect &operator-=(const QMargins &margins) noexcept;
 
 #if QT_DEPRECATED_SINCE(5, 0)
-    Q_REQUIRED_RESULT QT_DEPRECATED QRect unite(const QRect &r) const Q_DECL_NOTHROW { return united(r); }
-    Q_REQUIRED_RESULT QT_DEPRECATED QRect intersect(const QRect &r) const Q_DECL_NOTHROW { return intersected(r); }
+    Q_REQUIRED_RESULT QT_DEPRECATED QRect unite(const QRect &r) const noexcept { return united(r); }
+    Q_REQUIRED_RESULT QT_DEPRECATED QRect intersect(const QRect &r) const noexcept { return intersected(r); }
 #endif
 
-    friend Q_DECL_CONSTEXPR inline bool operator==(const QRect &, const QRect &) Q_DECL_NOTHROW;
-    friend Q_DECL_CONSTEXPR inline bool operator!=(const QRect &, const QRect &) Q_DECL_NOTHROW;
+    friend Q_DECL_CONSTEXPR inline bool operator==(const QRect &, const QRect &) noexcept;
+    friend Q_DECL_CONSTEXPR inline bool operator!=(const QRect &, const QRect &) noexcept;
 
 #if defined(Q_OS_DARWIN) || defined(Q_QDOC)
-    Q_REQUIRED_RESULT CGRect toCGRect() const Q_DECL_NOTHROW;
+    Q_REQUIRED_RESULT CGRect toCGRect() const noexcept;
 #endif
 
 private:
@@ -165,8 +165,8 @@ private:
 };
 Q_DECLARE_TYPEINFO(QRect, Q_MOVABLE_TYPE);
 
-Q_DECL_CONSTEXPR inline bool operator==(const QRect &, const QRect &) Q_DECL_NOTHROW;
-Q_DECL_CONSTEXPR inline bool operator!=(const QRect &, const QRect &) Q_DECL_NOTHROW;
+Q_DECL_CONSTEXPR inline bool operator==(const QRect &, const QRect &) noexcept;
+Q_DECL_CONSTEXPR inline bool operator!=(const QRect &, const QRect &) noexcept;
 
 
 /*****************************************************************************
@@ -181,97 +181,97 @@ Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QRect &);
   QRect inline member functions
  *****************************************************************************/
 
-Q_DECL_CONSTEXPR inline QRect::QRect(int aleft, int atop, int awidth, int aheight) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect::QRect(int aleft, int atop, int awidth, int aheight) noexcept
     : x1(aleft), y1(atop), x2(aleft + awidth - 1), y2(atop + aheight - 1) {}
 
-Q_DECL_CONSTEXPR inline QRect::QRect(const QPoint &atopLeft, const QPoint &abottomRight) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect::QRect(const QPoint &atopLeft, const QPoint &abottomRight) noexcept
     : x1(atopLeft.x()), y1(atopLeft.y()), x2(abottomRight.x()), y2(abottomRight.y()) {}
 
-Q_DECL_CONSTEXPR inline QRect::QRect(const QPoint &atopLeft, const QSize &asize) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect::QRect(const QPoint &atopLeft, const QSize &asize) noexcept
     : x1(atopLeft.x()), y1(atopLeft.y()), x2(atopLeft.x()+asize.width() - 1), y2(atopLeft.y()+asize.height() - 1) {}
 
-Q_DECL_CONSTEXPR inline bool QRect::isNull() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QRect::isNull() const noexcept
 { return x2 == x1 - 1 && y2 == y1 - 1; }
 
-Q_DECL_CONSTEXPR inline bool QRect::isEmpty() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QRect::isEmpty() const noexcept
 { return x1 > x2 || y1 > y2; }
 
-Q_DECL_CONSTEXPR inline bool QRect::isValid() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QRect::isValid() const noexcept
 { return x1 <= x2 && y1 <= y2; }
 
-Q_DECL_CONSTEXPR inline int QRect::left() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QRect::left() const noexcept
 { return x1; }
 
-Q_DECL_CONSTEXPR inline int QRect::top() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QRect::top() const noexcept
 { return y1; }
 
-Q_DECL_CONSTEXPR inline int QRect::right() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QRect::right() const noexcept
 { return x2; }
 
-Q_DECL_CONSTEXPR inline int QRect::bottom() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QRect::bottom() const noexcept
 { return y2; }
 
-Q_DECL_CONSTEXPR inline int QRect::x() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QRect::x() const noexcept
 { return x1; }
 
-Q_DECL_CONSTEXPR inline int QRect::y() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QRect::y() const noexcept
 { return y1; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setLeft(int pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setLeft(int pos) noexcept
 { x1 = pos; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setTop(int pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setTop(int pos) noexcept
 { y1 = pos; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setRight(int pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setRight(int pos) noexcept
 { x2 = pos; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setBottom(int pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setBottom(int pos) noexcept
 { y2 = pos; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setTopLeft(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setTopLeft(const QPoint &p) noexcept
 { x1 = p.x(); y1 = p.y(); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setBottomRight(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setBottomRight(const QPoint &p) noexcept
 { x2 = p.x(); y2 = p.y(); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setTopRight(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setTopRight(const QPoint &p) noexcept
 { x2 = p.x(); y1 = p.y(); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setBottomLeft(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setBottomLeft(const QPoint &p) noexcept
 { x1 = p.x(); y2 = p.y(); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setX(int ax) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setX(int ax) noexcept
 { x1 = ax; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setY(int ay) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setY(int ay) noexcept
 { y1 = ay; }
 
-Q_DECL_CONSTEXPR inline QPoint QRect::topLeft() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QPoint QRect::topLeft() const noexcept
 { return QPoint(x1, y1); }
 
-Q_DECL_CONSTEXPR inline QPoint QRect::bottomRight() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QPoint QRect::bottomRight() const noexcept
 { return QPoint(x2, y2); }
 
-Q_DECL_CONSTEXPR inline QPoint QRect::topRight() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QPoint QRect::topRight() const noexcept
 { return QPoint(x2, y1); }
 
-Q_DECL_CONSTEXPR inline QPoint QRect::bottomLeft() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QPoint QRect::bottomLeft() const noexcept
 { return QPoint(x1, y2); }
 
-Q_DECL_CONSTEXPR inline QPoint QRect::center() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QPoint QRect::center() const noexcept
 { return QPoint(int((qint64(x1)+x2)/2), int((qint64(y1)+y2)/2)); } // cast avoids overflow on addition
 
-Q_DECL_CONSTEXPR inline int QRect::width() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QRect::width() const noexcept
 { return  x2 - x1 + 1; }
 
-Q_DECL_CONSTEXPR inline int QRect::height() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QRect::height() const noexcept
 { return  y2 - y1 + 1; }
 
-Q_DECL_CONSTEXPR inline QSize QRect::size() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QSize QRect::size() const noexcept
 { return QSize(width(), height()); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::translate(int dx, int dy) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::translate(int dx, int dy) noexcept
 {
     x1 += dx;
     y1 += dy;
@@ -279,7 +279,7 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRect::translate(int dx, int dy) Q_DECL_NOT
     y2 += dy;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::translate(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::translate(const QPoint &p) noexcept
 {
     x1 += p.x();
     y1 += p.y();
@@ -287,16 +287,16 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRect::translate(const QPoint &p) Q_DECL_NO
     y2 += p.y();
 }
 
-Q_DECL_CONSTEXPR inline QRect QRect::translated(int dx, int dy) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect QRect::translated(int dx, int dy) const noexcept
 { return QRect(QPoint(x1 + dx, y1 + dy), QPoint(x2 + dx, y2 + dy)); }
 
-Q_DECL_CONSTEXPR inline QRect QRect::translated(const QPoint &p) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect QRect::translated(const QPoint &p) const noexcept
 { return QRect(QPoint(x1 + p.x(), y1 + p.y()), QPoint(x2 + p.x(), y2 + p.y())); }
 
-Q_DECL_CONSTEXPR inline QRect QRect::transposed() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect QRect::transposed() const noexcept
 { return QRect(topLeft(), size().transposed()); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTo(int ax, int ay) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTo(int ax, int ay) noexcept
 {
     x2 += ax - x1;
     y2 += ay - y1;
@@ -304,7 +304,7 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTo(int ax, int ay) Q_DECL_NOTHRO
     y1 = ay;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTo(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTo(const QPoint &p) noexcept
 {
     x2 += p.x() - x1;
     y2 += p.y() - y1;
@@ -312,49 +312,49 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTo(const QPoint &p) Q_DECL_NOTHR
     y1 = p.y();
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveLeft(int pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveLeft(int pos) noexcept
 { x2 += (pos - x1); x1 = pos; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTop(int pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTop(int pos) noexcept
 { y2 += (pos - y1); y1 = pos; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveRight(int pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveRight(int pos) noexcept
 {
     x1 += (pos - x2);
     x2 = pos;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveBottom(int pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveBottom(int pos) noexcept
 {
     y1 += (pos - y2);
     y2 = pos;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTopLeft(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTopLeft(const QPoint &p) noexcept
 {
     moveLeft(p.x());
     moveTop(p.y());
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveBottomRight(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveBottomRight(const QPoint &p) noexcept
 {
     moveRight(p.x());
     moveBottom(p.y());
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTopRight(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveTopRight(const QPoint &p) noexcept
 {
     moveRight(p.x());
     moveTop(p.y());
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveBottomLeft(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveBottomLeft(const QPoint &p) noexcept
 {
     moveLeft(p.x());
     moveBottom(p.y());
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveCenter(const QPoint &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::moveCenter(const QPoint &p) noexcept
 {
     int w = x2 - x1;
     int h = y2 - y1;
@@ -372,7 +372,7 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRect::getRect(int *ax, int *ay, int *aw, i
     *ah = y2 - y1 + 1;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setRect(int ax, int ay, int aw, int ah) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setRect(int ax, int ay, int aw, int ah) noexcept
 {
     x1 = ax;
     y1 = ay;
@@ -388,7 +388,7 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRect::getCoords(int *xp1, int *yp1, int *x
     *yp2 = y2;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setCoords(int xp1, int yp1, int xp2, int yp2) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setCoords(int xp1, int yp1, int xp2, int yp2) noexcept
 {
     x1 = xp1;
     y1 = yp1;
@@ -396,10 +396,10 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRect::setCoords(int xp1, int yp1, int xp2,
     y2 = yp2;
 }
 
-Q_DECL_CONSTEXPR inline QRect QRect::adjusted(int xp1, int yp1, int xp2, int yp2) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect QRect::adjusted(int xp1, int yp1, int xp2, int yp2) const noexcept
 { return QRect(QPoint(x1 + xp1, y1 + yp1), QPoint(x2 + xp2, y2 + yp2)); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::adjust(int dx1, int dy1, int dx2, int dy2) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::adjust(int dx1, int dy1, int dx2, int dy2) noexcept
 {
     x1 += dx1;
     y1 += dy1;
@@ -407,97 +407,97 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRect::adjust(int dx1, int dy1, int dx2, in
     y2 += dy2;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setWidth(int w) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setWidth(int w) noexcept
 { x2 = (x1 + w - 1); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setHeight(int h) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setHeight(int h) noexcept
 { y2 = (y1 + h - 1); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRect::setSize(const QSize &s) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRect::setSize(const QSize &s) noexcept
 {
     x2 = (s.width()  + x1 - 1);
     y2 = (s.height() + y1 - 1);
 }
 
-inline bool QRect::contains(int ax, int ay, bool aproper) const Q_DECL_NOTHROW
+inline bool QRect::contains(int ax, int ay, bool aproper) const noexcept
 {
     return contains(QPoint(ax, ay), aproper);
 }
 
-inline bool QRect::contains(int ax, int ay) const Q_DECL_NOTHROW
+inline bool QRect::contains(int ax, int ay) const noexcept
 {
     return contains(QPoint(ax, ay), false);
 }
 
-inline QRect& QRect::operator|=(const QRect &r) Q_DECL_NOTHROW
+inline QRect& QRect::operator|=(const QRect &r) noexcept
 {
     *this = *this | r;
     return *this;
 }
 
-inline QRect& QRect::operator&=(const QRect &r) Q_DECL_NOTHROW
+inline QRect& QRect::operator&=(const QRect &r) noexcept
 {
     *this = *this & r;
     return *this;
 }
 
-inline QRect QRect::intersected(const QRect &other) const Q_DECL_NOTHROW
+inline QRect QRect::intersected(const QRect &other) const noexcept
 {
     return *this & other;
 }
 
-inline QRect QRect::united(const QRect &r) const Q_DECL_NOTHROW
+inline QRect QRect::united(const QRect &r) const noexcept
 {
     return *this | r;
 }
 
-Q_DECL_CONSTEXPR inline bool operator==(const QRect &r1, const QRect &r2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator==(const QRect &r1, const QRect &r2) noexcept
 {
     return r1.x1==r2.x1 && r1.x2==r2.x2 && r1.y1==r2.y1 && r1.y2==r2.y2;
 }
 
-Q_DECL_CONSTEXPR inline bool operator!=(const QRect &r1, const QRect &r2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator!=(const QRect &r1, const QRect &r2) noexcept
 {
     return r1.x1!=r2.x1 || r1.x2!=r2.x2 || r1.y1!=r2.y1 || r1.y2!=r2.y2;
 }
 
-Q_DECL_CONSTEXPR inline QRect operator+(const QRect &rectangle, const QMargins &margins) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect operator+(const QRect &rectangle, const QMargins &margins) noexcept
 {
     return QRect(QPoint(rectangle.left() - margins.left(), rectangle.top() - margins.top()),
                  QPoint(rectangle.right() + margins.right(), rectangle.bottom() + margins.bottom()));
 }
 
-Q_DECL_CONSTEXPR inline QRect operator+(const QMargins &margins, const QRect &rectangle) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect operator+(const QMargins &margins, const QRect &rectangle) noexcept
 {
     return QRect(QPoint(rectangle.left() - margins.left(), rectangle.top() - margins.top()),
                  QPoint(rectangle.right() + margins.right(), rectangle.bottom() + margins.bottom()));
 }
 
-Q_DECL_CONSTEXPR inline QRect operator-(const QRect &lhs, const QMargins &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect operator-(const QRect &lhs, const QMargins &rhs) noexcept
 {
     return QRect(QPoint(lhs.left() + rhs.left(), lhs.top() + rhs.top()),
                  QPoint(lhs.right() - rhs.right(), lhs.bottom() - rhs.bottom()));
 }
 
-Q_DECL_CONSTEXPR inline QRect QRect::marginsAdded(const QMargins &margins) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect QRect::marginsAdded(const QMargins &margins) const noexcept
 {
     return QRect(QPoint(x1 - margins.left(), y1 - margins.top()),
                  QPoint(x2 + margins.right(), y2 + margins.bottom()));
 }
 
-Q_DECL_CONSTEXPR inline QRect QRect::marginsRemoved(const QMargins &margins) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect QRect::marginsRemoved(const QMargins &margins) const noexcept
 {
     return QRect(QPoint(x1 + margins.left(), y1 + margins.top()),
                  QPoint(x2 - margins.right(), y2 - margins.bottom()));
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QRect &QRect::operator+=(const QMargins &margins) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QRect &QRect::operator+=(const QMargins &margins) noexcept
 {
     *this = marginsAdded(margins);
     return *this;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QRect &QRect::operator-=(const QMargins &margins) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QRect &QRect::operator-=(const QMargins &margins) noexcept
 {
     *this = marginsRemoved(margins);
     return *this;
@@ -511,110 +511,110 @@ Q_CORE_EXPORT QDebug operator<<(QDebug, const QRect &);
 class Q_CORE_EXPORT QRectF
 {
 public:
-    Q_DECL_CONSTEXPR QRectF() Q_DECL_NOTHROW : xp(0.), yp(0.), w(0.), h(0.) {}
-    Q_DECL_CONSTEXPR QRectF(const QPointF &topleft, const QSizeF &size) Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QRectF(const QPointF &topleft, const QPointF &bottomRight) Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QRectF(qreal left, qreal top, qreal width, qreal height) Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QRectF(const QRect &rect) Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline bool isNull() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline bool isEmpty() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline bool isValid() const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT QRectF normalized() const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline qreal left() const Q_DECL_NOTHROW { return xp; }
-    Q_DECL_CONSTEXPR inline qreal top() const Q_DECL_NOTHROW { return yp; }
-    Q_DECL_CONSTEXPR inline qreal right() const Q_DECL_NOTHROW { return xp + w; }
-    Q_DECL_CONSTEXPR inline qreal bottom() const Q_DECL_NOTHROW { return yp + h; }
-
-    Q_DECL_CONSTEXPR inline qreal x() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline qreal y() const Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setLeft(qreal pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setTop(qreal pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setRight(qreal pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setBottom(qreal pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setX(qreal pos) Q_DECL_NOTHROW { setLeft(pos); }
-    Q_DECL_RELAXED_CONSTEXPR inline void setY(qreal pos) Q_DECL_NOTHROW { setTop(pos); }
-
-    Q_DECL_CONSTEXPR inline QPointF topLeft() const Q_DECL_NOTHROW { return QPointF(xp, yp); }
-    Q_DECL_CONSTEXPR inline QPointF bottomRight() const Q_DECL_NOTHROW { return QPointF(xp+w, yp+h); }
-    Q_DECL_CONSTEXPR inline QPointF topRight() const Q_DECL_NOTHROW { return QPointF(xp+w, yp); }
-    Q_DECL_CONSTEXPR inline QPointF bottomLeft() const Q_DECL_NOTHROW { return QPointF(xp, yp+h); }
-    Q_DECL_CONSTEXPR inline QPointF center() const Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline void setTopLeft(const QPointF &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setBottomRight(const QPointF &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setTopRight(const QPointF &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setBottomLeft(const QPointF &p) Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline void moveLeft(qreal pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveTop(qreal pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveRight(qreal pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveBottom(qreal pos) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveTopLeft(const QPointF &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveBottomRight(const QPointF &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveTopRight(const QPointF &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveBottomLeft(const QPointF &p) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveCenter(const QPointF &p) Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline void translate(qreal dx, qreal dy) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void translate(const QPointF &p) Q_DECL_NOTHROW;
-
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRectF translated(qreal dx, qreal dy) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRectF translated(const QPointF &p) const Q_DECL_NOTHROW;
-
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRectF transposed() const Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline void moveTo(qreal x, qreal y) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void moveTo(const QPointF &p) Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline void setRect(qreal x, qreal y, qreal w, qreal h) Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR QRectF() noexcept : xp(0.), yp(0.), w(0.), h(0.) {}
+    Q_DECL_CONSTEXPR QRectF(const QPointF &topleft, const QSizeF &size) noexcept;
+    Q_DECL_CONSTEXPR QRectF(const QPointF &topleft, const QPointF &bottomRight) noexcept;
+    Q_DECL_CONSTEXPR QRectF(qreal left, qreal top, qreal width, qreal height) noexcept;
+    Q_DECL_CONSTEXPR QRectF(const QRect &rect) noexcept;
+
+    Q_DECL_CONSTEXPR inline bool isNull() const noexcept;
+    Q_DECL_CONSTEXPR inline bool isEmpty() const noexcept;
+    Q_DECL_CONSTEXPR inline bool isValid() const noexcept;
+    Q_REQUIRED_RESULT QRectF normalized() const noexcept;
+
+    Q_DECL_CONSTEXPR inline qreal left() const noexcept { return xp; }
+    Q_DECL_CONSTEXPR inline qreal top() const noexcept { return yp; }
+    Q_DECL_CONSTEXPR inline qreal right() const noexcept { return xp + w; }
+    Q_DECL_CONSTEXPR inline qreal bottom() const noexcept { return yp + h; }
+
+    Q_DECL_CONSTEXPR inline qreal x() const noexcept;
+    Q_DECL_CONSTEXPR inline qreal y() const noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setLeft(qreal pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setTop(qreal pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setRight(qreal pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setBottom(qreal pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setX(qreal pos) noexcept { setLeft(pos); }
+    Q_DECL_RELAXED_CONSTEXPR inline void setY(qreal pos) noexcept { setTop(pos); }
+
+    Q_DECL_CONSTEXPR inline QPointF topLeft() const noexcept { return QPointF(xp, yp); }
+    Q_DECL_CONSTEXPR inline QPointF bottomRight() const noexcept { return QPointF(xp+w, yp+h); }
+    Q_DECL_CONSTEXPR inline QPointF topRight() const noexcept { return QPointF(xp+w, yp); }
+    Q_DECL_CONSTEXPR inline QPointF bottomLeft() const noexcept { return QPointF(xp, yp+h); }
+    Q_DECL_CONSTEXPR inline QPointF center() const noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline void setTopLeft(const QPointF &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setBottomRight(const QPointF &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setTopRight(const QPointF &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setBottomLeft(const QPointF &p) noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline void moveLeft(qreal pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveTop(qreal pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveRight(qreal pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveBottom(qreal pos) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveTopLeft(const QPointF &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveBottomRight(const QPointF &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveTopRight(const QPointF &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveBottomLeft(const QPointF &p) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveCenter(const QPointF &p) noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline void translate(qreal dx, qreal dy) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void translate(const QPointF &p) noexcept;
+
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRectF translated(qreal dx, qreal dy) const noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRectF translated(const QPointF &p) const noexcept;
+
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRectF transposed() const noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline void moveTo(qreal x, qreal y) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void moveTo(const QPointF &p) noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline void setRect(qreal x, qreal y, qreal w, qreal h) noexcept;
     Q_DECL_RELAXED_CONSTEXPR inline void getRect(qreal *x, qreal *y, qreal *w, qreal *h) const;
 
-    Q_DECL_RELAXED_CONSTEXPR inline void setCoords(qreal x1, qreal y1, qreal x2, qreal y2) Q_DECL_NOTHROW;
+    Q_DECL_RELAXED_CONSTEXPR inline void setCoords(qreal x1, qreal y1, qreal x2, qreal y2) noexcept;
     Q_DECL_RELAXED_CONSTEXPR inline void getCoords(qreal *x1, qreal *y1, qreal *x2, qreal *y2) const;
 
-    Q_DECL_RELAXED_CONSTEXPR inline void adjust(qreal x1, qreal y1, qreal x2, qreal y2) Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRectF adjusted(qreal x1, qreal y1, qreal x2, qreal y2) const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline QSizeF size() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline qreal width() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline qreal height() const Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setWidth(qreal w) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setHeight(qreal h) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setSize(const QSizeF &s) Q_DECL_NOTHROW;
-
-    QRectF operator|(const QRectF &r) const Q_DECL_NOTHROW;
-    QRectF operator&(const QRectF &r) const Q_DECL_NOTHROW;
-    inline QRectF& operator|=(const QRectF &r) Q_DECL_NOTHROW;
-    inline QRectF& operator&=(const QRectF &r) Q_DECL_NOTHROW;
-
-    bool contains(const QRectF &r) const Q_DECL_NOTHROW;
-    bool contains(const QPointF &p) const Q_DECL_NOTHROW;
-    inline bool contains(qreal x, qreal y) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT inline QRectF united(const QRectF &other) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT inline QRectF intersected(const QRectF &other) const Q_DECL_NOTHROW;
-    bool intersects(const QRectF &r) const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline QRectF marginsAdded(const QMarginsF &margins) const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline QRectF marginsRemoved(const QMarginsF &margins) const Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline QRectF &operator+=(const QMarginsF &margins) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline QRectF &operator-=(const QMarginsF &margins) Q_DECL_NOTHROW;
+    Q_DECL_RELAXED_CONSTEXPR inline void adjust(qreal x1, qreal y1, qreal x2, qreal y2) noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRectF adjusted(qreal x1, qreal y1, qreal x2, qreal y2) const noexcept;
+
+    Q_DECL_CONSTEXPR inline QSizeF size() const noexcept;
+    Q_DECL_CONSTEXPR inline qreal width() const noexcept;
+    Q_DECL_CONSTEXPR inline qreal height() const noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setWidth(qreal w) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setHeight(qreal h) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setSize(const QSizeF &s) noexcept;
+
+    QRectF operator|(const QRectF &r) const noexcept;
+    QRectF operator&(const QRectF &r) const noexcept;
+    inline QRectF& operator|=(const QRectF &r) noexcept;
+    inline QRectF& operator&=(const QRectF &r) noexcept;
+
+    bool contains(const QRectF &r) const noexcept;
+    bool contains(const QPointF &p) const noexcept;
+    inline bool contains(qreal x, qreal y) const noexcept;
+    Q_REQUIRED_RESULT inline QRectF united(const QRectF &other) const noexcept;
+    Q_REQUIRED_RESULT inline QRectF intersected(const QRectF &other) const noexcept;
+    bool intersects(const QRectF &r) const noexcept;
+
+    Q_DECL_CONSTEXPR inline QRectF marginsAdded(const QMarginsF &margins) const noexcept;
+    Q_DECL_CONSTEXPR inline QRectF marginsRemoved(const QMarginsF &margins) const noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline QRectF &operator+=(const QMarginsF &margins) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline QRectF &operator-=(const QMarginsF &margins) noexcept;
 
 #if QT_DEPRECATED_SINCE(5, 0)
-    Q_REQUIRED_RESULT QT_DEPRECATED QRectF unite(const QRectF &r) const Q_DECL_NOTHROW { return united(r); }
-    Q_REQUIRED_RESULT QT_DEPRECATED QRectF intersect(const QRectF &r) const Q_DECL_NOTHROW { return intersected(r); }
+    Q_REQUIRED_RESULT QT_DEPRECATED QRectF unite(const QRectF &r) const noexcept { return united(r); }
+    Q_REQUIRED_RESULT QT_DEPRECATED QRectF intersect(const QRectF &r) const noexcept { return intersected(r); }
 #endif
 
-    friend Q_DECL_CONSTEXPR inline bool operator==(const QRectF &, const QRectF &) Q_DECL_NOTHROW;
-    friend Q_DECL_CONSTEXPR inline bool operator!=(const QRectF &, const QRectF &) Q_DECL_NOTHROW;
+    friend Q_DECL_CONSTEXPR inline bool operator==(const QRectF &, const QRectF &) noexcept;
+    friend Q_DECL_CONSTEXPR inline bool operator!=(const QRectF &, const QRectF &) noexcept;
 
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRect toRect() const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT QRect toAlignedRect() const Q_DECL_NOTHROW;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QRect toRect() const noexcept;
+    Q_REQUIRED_RESULT QRect toAlignedRect() const noexcept;
 
 #if defined(Q_OS_DARWIN) || defined(Q_QDOC)
-    Q_REQUIRED_RESULT static QRectF fromCGRect(CGRect rect) Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT CGRect toCGRect() const Q_DECL_NOTHROW;
+    Q_REQUIRED_RESULT static QRectF fromCGRect(CGRect rect) noexcept;
+    Q_REQUIRED_RESULT CGRect toCGRect() const noexcept;
 #endif
 
 private:
@@ -625,8 +625,8 @@ private:
 };
 Q_DECLARE_TYPEINFO(QRectF, Q_MOVABLE_TYPE);
 
-Q_DECL_CONSTEXPR inline bool operator==(const QRectF &, const QRectF &) Q_DECL_NOTHROW;
-Q_DECL_CONSTEXPR inline bool operator!=(const QRectF &, const QRectF &) Q_DECL_NOTHROW;
+Q_DECL_CONSTEXPR inline bool operator==(const QRectF &, const QRectF &) noexcept;
+Q_DECL_CONSTEXPR inline bool operator!=(const QRectF &, const QRectF &) noexcept;
 
 
 /*****************************************************************************
@@ -641,23 +641,23 @@ Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QRectF &);
   QRectF inline member functions
  *****************************************************************************/
 
-Q_DECL_CONSTEXPR inline QRectF::QRectF(qreal aleft, qreal atop, qreal awidth, qreal aheight) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF::QRectF(qreal aleft, qreal atop, qreal awidth, qreal aheight) noexcept
     : xp(aleft), yp(atop), w(awidth), h(aheight)
 {
 }
 
-Q_DECL_CONSTEXPR inline QRectF::QRectF(const QPointF &atopLeft, const QSizeF &asize) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF::QRectF(const QPointF &atopLeft, const QSizeF &asize) noexcept
     : xp(atopLeft.x()), yp(atopLeft.y()), w(asize.width()), h(asize.height())
 {
 }
 
 
-Q_DECL_CONSTEXPR inline QRectF::QRectF(const QPointF &atopLeft, const QPointF &abottomRight) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF::QRectF(const QPointF &atopLeft, const QPointF &abottomRight) noexcept
     : xp(atopLeft.x()), yp(atopLeft.y()), w(abottomRight.x() - atopLeft.x()), h(abottomRight.y() - atopLeft.y())
 {
 }
 
-Q_DECL_CONSTEXPR inline QRectF::QRectF(const QRect &r) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF::QRectF(const QRect &r) noexcept
     : xp(r.x()), yp(r.y()), w(r.width()), h(r.height())
 {
 }
@@ -666,117 +666,117 @@ QT_WARNING_PUSH
 QT_WARNING_DISABLE_CLANG("-Wfloat-equal")
 QT_WARNING_DISABLE_GCC("-Wfloat-equal")
 
-Q_DECL_CONSTEXPR inline bool QRectF::isNull() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QRectF::isNull() const noexcept
 { return w == 0. && h == 0.; }
 
-Q_DECL_CONSTEXPR inline bool QRectF::isEmpty() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QRectF::isEmpty() const noexcept
 { return w <= 0. || h <= 0.; }
 
 QT_WARNING_POP
 
-Q_DECL_CONSTEXPR inline bool QRectF::isValid() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QRectF::isValid() const noexcept
 { return w > 0. && h > 0.; }
 
-Q_DECL_CONSTEXPR inline qreal QRectF::x() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline qreal QRectF::x() const noexcept
 { return xp; }
 
-Q_DECL_CONSTEXPR inline qreal QRectF::y() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline qreal QRectF::y() const noexcept
 { return yp; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setLeft(qreal pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setLeft(qreal pos) noexcept
 { qreal diff = pos - xp; xp += diff; w -= diff; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setRight(qreal pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setRight(qreal pos) noexcept
 { w = pos - xp; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setTop(qreal pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setTop(qreal pos) noexcept
 { qreal diff = pos - yp; yp += diff; h -= diff; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setBottom(qreal pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setBottom(qreal pos) noexcept
 { h = pos - yp; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setTopLeft(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setTopLeft(const QPointF &p) noexcept
 { setLeft(p.x()); setTop(p.y()); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setTopRight(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setTopRight(const QPointF &p) noexcept
 { setRight(p.x()); setTop(p.y()); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setBottomLeft(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setBottomLeft(const QPointF &p) noexcept
 { setLeft(p.x()); setBottom(p.y()); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setBottomRight(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setBottomRight(const QPointF &p) noexcept
 { setRight(p.x()); setBottom(p.y()); }
 
-Q_DECL_CONSTEXPR inline QPointF QRectF::center() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QPointF QRectF::center() const noexcept
 { return QPointF(xp + w/2, yp + h/2); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveLeft(qreal pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveLeft(qreal pos) noexcept
 { xp = pos; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveTop(qreal pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveTop(qreal pos) noexcept
 { yp = pos; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveRight(qreal pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveRight(qreal pos) noexcept
 { xp = pos - w; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveBottom(qreal pos) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveBottom(qreal pos) noexcept
 { yp = pos - h; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveTopLeft(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveTopLeft(const QPointF &p) noexcept
 { moveLeft(p.x()); moveTop(p.y()); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveTopRight(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveTopRight(const QPointF &p) noexcept
 { moveRight(p.x()); moveTop(p.y()); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveBottomLeft(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveBottomLeft(const QPointF &p) noexcept
 { moveLeft(p.x()); moveBottom(p.y()); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveBottomRight(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveBottomRight(const QPointF &p) noexcept
 { moveRight(p.x()); moveBottom(p.y()); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveCenter(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveCenter(const QPointF &p) noexcept
 { xp = p.x() - w/2; yp = p.y() - h/2; }
 
-Q_DECL_CONSTEXPR inline qreal QRectF::width() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline qreal QRectF::width() const noexcept
 { return w; }
 
-Q_DECL_CONSTEXPR inline qreal QRectF::height() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline qreal QRectF::height() const noexcept
 { return h; }
 
-Q_DECL_CONSTEXPR inline QSizeF QRectF::size() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QSizeF QRectF::size() const noexcept
 { return QSizeF(w, h); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::translate(qreal dx, qreal dy) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::translate(qreal dx, qreal dy) noexcept
 {
     xp += dx;
     yp += dy;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::translate(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::translate(const QPointF &p) noexcept
 {
     xp += p.x();
     yp += p.y();
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveTo(qreal ax, qreal ay) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveTo(qreal ax, qreal ay) noexcept
 {
     xp = ax;
     yp = ay;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveTo(const QPointF &p) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::moveTo(const QPointF &p) noexcept
 {
     xp = p.x();
     yp = p.y();
 }
 
-Q_DECL_CONSTEXPR inline QRectF QRectF::translated(qreal dx, qreal dy) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF QRectF::translated(qreal dx, qreal dy) const noexcept
 { return QRectF(xp + dx, yp + dy, w, h); }
 
-Q_DECL_CONSTEXPR inline QRectF QRectF::translated(const QPointF &p) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF QRectF::translated(const QPointF &p) const noexcept
 { return QRectF(xp + p.x(), yp + p.y(), w, h); }
 
-Q_DECL_CONSTEXPR inline QRectF QRectF::transposed() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF QRectF::transposed() const noexcept
 { return QRectF(topLeft(), size().transposed()); }
 
 Q_DECL_RELAXED_CONSTEXPR inline void QRectF::getRect(qreal *ax, qreal *ay, qreal *aaw, qreal *aah) const
@@ -787,7 +787,7 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRectF::getRect(qreal *ax, qreal *ay, qreal
     *aah = this->h;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setRect(qreal ax, qreal ay, qreal aaw, qreal aah) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setRect(qreal ax, qreal ay, qreal aaw, qreal aah) noexcept
 {
     this->xp = ax;
     this->yp = ay;
@@ -803,7 +803,7 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRectF::getCoords(qreal *xp1, qreal *yp1, q
     *yp2 = yp + h;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setCoords(qreal xp1, qreal yp1, qreal xp2, qreal yp2) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setCoords(qreal xp1, qreal yp1, qreal xp2, qreal yp2) noexcept
 {
     xp = xp1;
     yp = yp1;
@@ -811,105 +811,105 @@ Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setCoords(qreal xp1, qreal yp1, qre
     h = yp2 - yp1;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::adjust(qreal xp1, qreal yp1, qreal xp2, qreal yp2) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::adjust(qreal xp1, qreal yp1, qreal xp2, qreal yp2) noexcept
 { xp += xp1; yp += yp1; w += xp2 - xp1; h += yp2 - yp1; }
 
-Q_DECL_CONSTEXPR inline QRectF QRectF::adjusted(qreal xp1, qreal yp1, qreal xp2, qreal yp2) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF QRectF::adjusted(qreal xp1, qreal yp1, qreal xp2, qreal yp2) const noexcept
 { return QRectF(xp + xp1, yp + yp1, w + xp2 - xp1, h + yp2 - yp1); }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setWidth(qreal aw) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setWidth(qreal aw) noexcept
 { this->w = aw; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setHeight(qreal ah) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setHeight(qreal ah) noexcept
 { this->h = ah; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setSize(const QSizeF &s) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QRectF::setSize(const QSizeF &s) noexcept
 {
     w = s.width();
     h = s.height();
 }
 
-inline bool QRectF::contains(qreal ax, qreal ay) const Q_DECL_NOTHROW
+inline bool QRectF::contains(qreal ax, qreal ay) const noexcept
 {
     return contains(QPointF(ax, ay));
 }
 
-inline QRectF& QRectF::operator|=(const QRectF &r) Q_DECL_NOTHROW
+inline QRectF& QRectF::operator|=(const QRectF &r) noexcept
 {
     *this = *this | r;
     return *this;
 }
 
-inline QRectF& QRectF::operator&=(const QRectF &r) Q_DECL_NOTHROW
+inline QRectF& QRectF::operator&=(const QRectF &r) noexcept
 {
     *this = *this & r;
     return *this;
 }
 
-inline QRectF QRectF::intersected(const QRectF &r) const Q_DECL_NOTHROW
+inline QRectF QRectF::intersected(const QRectF &r) const noexcept
 {
     return *this & r;
 }
 
-inline QRectF QRectF::united(const QRectF &r) const Q_DECL_NOTHROW
+inline QRectF QRectF::united(const QRectF &r) const noexcept
 {
     return *this | r;
 }
 
-Q_DECL_CONSTEXPR inline bool operator==(const QRectF &r1, const QRectF &r2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator==(const QRectF &r1, const QRectF &r2) noexcept
 {
     return qFuzzyCompare(r1.xp, r2.xp) && qFuzzyCompare(r1.yp, r2.yp)
            && qFuzzyCompare(r1.w, r2.w) && qFuzzyCompare(r1.h, r2.h);
 }
 
-Q_DECL_CONSTEXPR inline bool operator!=(const QRectF &r1, const QRectF &r2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator!=(const QRectF &r1, const QRectF &r2) noexcept
 {
     return !qFuzzyCompare(r1.xp, r2.xp) || !qFuzzyCompare(r1.yp, r2.yp)
            || !qFuzzyCompare(r1.w, r2.w) || !qFuzzyCompare(r1.h, r2.h);
 }
 
-Q_DECL_CONSTEXPR inline QRect QRectF::toRect() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRect QRectF::toRect() const noexcept
 {
     return QRect(QPoint(qRound(xp), qRound(yp)), QPoint(qRound(xp + w) - 1, qRound(yp + h) - 1));
 }
 
-Q_DECL_CONSTEXPR inline QRectF operator+(const QRectF &lhs, const QMarginsF &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF operator+(const QRectF &lhs, const QMarginsF &rhs) noexcept
 {
     return QRectF(QPointF(lhs.left() - rhs.left(), lhs.top() - rhs.top()),
                   QSizeF(lhs.width() + rhs.left() + rhs.right(), lhs.height() + rhs.top() + rhs.bottom()));
 }
 
-Q_DECL_CONSTEXPR inline QRectF operator+(const QMarginsF &lhs, const QRectF &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF operator+(const QMarginsF &lhs, const QRectF &rhs) noexcept
 {
     return QRectF(QPointF(rhs.left() - lhs.left(), rhs.top() - lhs.top()),
                   QSizeF(rhs.width() + lhs.left() + lhs.right(), rhs.height() + lhs.top() + lhs.bottom()));
 }
 
-Q_DECL_CONSTEXPR inline QRectF operator-(const QRectF &lhs, const QMarginsF &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF operator-(const QRectF &lhs, const QMarginsF &rhs) noexcept
 {
     return QRectF(QPointF(lhs.left() + rhs.left(), lhs.top() + rhs.top()),
                   QSizeF(lhs.width() - rhs.left() - rhs.right(), lhs.height() - rhs.top() - rhs.bottom()));
 }
 
-Q_DECL_CONSTEXPR inline QRectF QRectF::marginsAdded(const QMarginsF &margins) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF QRectF::marginsAdded(const QMarginsF &margins) const noexcept
 {
     return QRectF(QPointF(xp - margins.left(), yp - margins.top()),
                   QSizeF(w + margins.left() + margins.right(), h + margins.top() + margins.bottom()));
 }
 
-Q_DECL_CONSTEXPR inline QRectF QRectF::marginsRemoved(const QMarginsF &margins) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QRectF QRectF::marginsRemoved(const QMarginsF &margins) const noexcept
 {
     return QRectF(QPointF(xp + margins.left(), yp + margins.top()),
                   QSizeF(w - margins.left() - margins.right(), h - margins.top() - margins.bottom()));
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QRectF &QRectF::operator+=(const QMarginsF &margins) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QRectF &QRectF::operator+=(const QMarginsF &margins) noexcept
 {
     *this = marginsAdded(margins);
     return *this;
 }
 
-Q_DECL_RELAXED_CONSTEXPR inline QRectF &QRectF::operator-=(const QMarginsF &margins) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QRectF &QRectF::operator-=(const QMarginsF &margins) noexcept
 {
     *this = marginsRemoved(margins);
     return *this;
diff --git a/src/corelib/tools/qrefcount.h b/src/corelib/tools/qrefcount.h
index 9586c3a79a..71adb41f28 100644
--- a/src/corelib/tools/qrefcount.h
+++ b/src/corelib/tools/qrefcount.h
@@ -51,7 +51,7 @@ namespace QtPrivate
 class RefCount
 {
 public:
-    inline bool ref() Q_DECL_NOTHROW {
+    inline bool ref() noexcept {
         int count = atomic.load();
 #if !defined(QT_NO_UNSHARABLE_CONTAINERS)
         if (count == 0) // !isSharable
@@ -62,7 +62,7 @@ public:
         return true;
     }
 
-    inline bool deref() Q_DECL_NOTHROW {
+    inline bool deref() noexcept {
         int count = atomic.load();
 #if !defined(QT_NO_UNSHARABLE_CONTAINERS)
         if (count == 0) // !isSharable
@@ -74,7 +74,7 @@ public:
     }
 
 #if !defined(QT_NO_UNSHARABLE_CONTAINERS)
-    bool setSharable(bool sharable) Q_DECL_NOTHROW
+    bool setSharable(bool sharable) noexcept
     {
         Q_ASSERT(!isShared());
         if (sharable)
@@ -83,27 +83,27 @@ public:
             return atomic.testAndSetRelaxed(1, 0);
     }
 
-    bool isSharable() const Q_DECL_NOTHROW
+    bool isSharable() const noexcept
     {
         // Sharable === Shared ownership.
         return atomic.load() != 0;
     }
 #endif
 
-    bool isStatic() const Q_DECL_NOTHROW
+    bool isStatic() const noexcept
     {
         // Persistent object, never deleted
         return atomic.load() == -1;
     }
 
-    bool isShared() const Q_DECL_NOTHROW
+    bool isShared() const noexcept
     {
         int count = atomic.load();
         return (count != 1) && (count != 0);
     }
 
-    void initializeOwned() Q_DECL_NOTHROW { atomic.store(1); }
-    void initializeUnsharable() Q_DECL_NOTHROW { atomic.store(0); }
+    void initializeOwned() noexcept { atomic.store(1); }
+    void initializeUnsharable() noexcept { atomic.store(0); }
 
     QBasicAtomicInt atomic;
 };
diff --git a/src/corelib/tools/qregexp.cpp b/src/corelib/tools/qregexp.cpp
index 589eb74520..d970843dea 100644
--- a/src/corelib/tools/qregexp.cpp
+++ b/src/corelib/tools/qregexp.cpp
@@ -890,7 +890,7 @@ static bool operator==(const QRegExpEngineKey &key1, const QRegExpEngineKey &key
            && key1.cs == key2.cs;
 }
 
-static uint qHash(const QRegExpEngineKey &key, uint seed = 0) Q_DECL_NOTHROW
+static uint qHash(const QRegExpEngineKey &key, uint seed = 0) noexcept
 {
     QtPrivate::QHashCombine hash;
     seed = hash(seed, key.pattern);
@@ -4046,7 +4046,7 @@ bool QRegExp::operator==(const QRegExp &rx) const
     Returns the hash value for \a key, using
     \a seed to seed the calculation.
 */
-uint qHash(const QRegExp &key, uint seed) Q_DECL_NOTHROW
+uint qHash(const QRegExp &key, uint seed) noexcept
 {
     QtPrivate::QHashCombine hash;
     seed = hash(seed, key.priv->engineKey);
diff --git a/src/corelib/tools/qregexp.h b/src/corelib/tools/qregexp.h
index b3fa242168..c043a06496 100644
--- a/src/corelib/tools/qregexp.h
+++ b/src/corelib/tools/qregexp.h
@@ -53,7 +53,7 @@ struct QRegExpPrivate;
 class QStringList;
 class QRegExp;
 
-Q_CORE_EXPORT uint qHash(const QRegExp &key, uint seed = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT uint qHash(const QRegExp &key, uint seed = 0) noexcept;
 
 class Q_CORE_EXPORT QRegExp
 {
@@ -74,9 +74,9 @@ public:
     ~QRegExp();
     QRegExp &operator=(const QRegExp &rx);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QRegExp &operator=(QRegExp &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QRegExp &operator=(QRegExp &&other) noexcept { swap(other); return *this; }
 #endif
-    void swap(QRegExp &other) Q_DECL_NOTHROW { qSwap(priv, other.priv); }
+    void swap(QRegExp &other) noexcept { qSwap(priv, other.priv); }
 
     bool operator==(const QRegExp &rx) const;
     inline bool operator!=(const QRegExp &rx) const { return !operator==(rx); }
@@ -112,7 +112,7 @@ public:
 
     static QString escape(const QString &str);
 
-    friend Q_CORE_EXPORT uint qHash(const QRegExp &key, uint seed) Q_DECL_NOTHROW;
+    friend Q_CORE_EXPORT uint qHash(const QRegExp &key, uint seed) noexcept;
 
 private:
     QRegExpPrivate *priv;
diff --git a/src/corelib/tools/qregularexpression.cpp b/src/corelib/tools/qregularexpression.cpp
index bdaa2d3243..ca1a866842 100644
--- a/src/corelib/tools/qregularexpression.cpp
+++ b/src/corelib/tools/qregularexpression.cpp
@@ -1810,7 +1810,7 @@ bool QRegularExpression::operator==(const QRegularExpression &re) const
     Returns the hash value for \a key, using
     \a seed to seed the calculation.
 */
-uint qHash(const QRegularExpression &key, uint seed) Q_DECL_NOTHROW
+uint qHash(const QRegularExpression &key, uint seed) noexcept
 {
     QtPrivate::QHashCombine hash;
     seed = hash(seed, key.d->pattern);
diff --git a/src/corelib/tools/qregularexpression.h b/src/corelib/tools/qregularexpression.h
index f9e7029550..f16b7e91be 100644
--- a/src/corelib/tools/qregularexpression.h
+++ b/src/corelib/tools/qregularexpression.h
@@ -59,7 +59,7 @@ class QRegularExpressionMatchIterator;
 struct QRegularExpressionPrivate;
 class QRegularExpression;
 
-Q_CORE_EXPORT uint qHash(const QRegularExpression &key, uint seed = 0) Q_DECL_NOTHROW;
+Q_CORE_EXPORT uint qHash(const QRegularExpression &key, uint seed = 0) noexcept;
 
 class Q_CORE_EXPORT QRegularExpression
 {
@@ -88,11 +88,11 @@ public:
     QRegularExpression &operator=(const QRegularExpression &re);
 
 #ifdef Q_COMPILER_RVALUE_REFS
-    QRegularExpression &operator=(QRegularExpression &&re) Q_DECL_NOTHROW
+    QRegularExpression &operator=(QRegularExpression &&re) noexcept
     { d.swap(re.d); return *this; }
 #endif
 
-    void swap(QRegularExpression &other) Q_DECL_NOTHROW { d.swap(other.d); }
+    void swap(QRegularExpression &other) noexcept { d.swap(other.d); }
 
     QString pattern() const;
     void setPattern(const QString &pattern);
@@ -157,7 +157,7 @@ private:
     friend class QRegularExpressionMatch;
     friend struct QRegularExpressionMatchPrivate;
     friend class QRegularExpressionMatchIterator;
-    friend Q_CORE_EXPORT uint qHash(const QRegularExpression &key, uint seed) Q_DECL_NOTHROW;
+    friend Q_CORE_EXPORT uint qHash(const QRegularExpression &key, uint seed) noexcept;
 
     QRegularExpression(QRegularExpressionPrivate &dd);
     QExplicitlySharedDataPointer<QRegularExpressionPrivate> d;
@@ -188,10 +188,10 @@ public:
     QRegularExpressionMatch &operator=(const QRegularExpressionMatch &match);
 
 #ifdef Q_COMPILER_RVALUE_REFS
-    QRegularExpressionMatch &operator=(QRegularExpressionMatch &&match) Q_DECL_NOTHROW
+    QRegularExpressionMatch &operator=(QRegularExpressionMatch &&match) noexcept
     { d.swap(match.d); return *this; }
 #endif
-    void swap(QRegularExpressionMatch &other) Q_DECL_NOTHROW { d.swap(other.d); }
+    void swap(QRegularExpressionMatch &other) noexcept { d.swap(other.d); }
 
     QRegularExpression regularExpression() const;
     QRegularExpression::MatchType matchType() const;
@@ -258,10 +258,10 @@ public:
     QRegularExpressionMatchIterator(const QRegularExpressionMatchIterator &iterator);
     QRegularExpressionMatchIterator &operator=(const QRegularExpressionMatchIterator &iterator);
 #ifdef Q_COMPILER_RVALUE_REFS
-    QRegularExpressionMatchIterator &operator=(QRegularExpressionMatchIterator &&iterator) Q_DECL_NOTHROW
+    QRegularExpressionMatchIterator &operator=(QRegularExpressionMatchIterator &&iterator) noexcept
     { d.swap(iterator.d); return *this; }
 #endif
-    void swap(QRegularExpressionMatchIterator &other) Q_DECL_NOTHROW { d.swap(other.d); }
+    void swap(QRegularExpressionMatchIterator &other) noexcept { d.swap(other.d); }
 
     bool isValid() const;
 
diff --git a/src/corelib/tools/qringbuffer_p.h b/src/corelib/tools/qringbuffer_p.h
index 76ab4a5b62..838cb31697 100644
--- a/src/corelib/tools/qringbuffer_p.h
+++ b/src/corelib/tools/qringbuffer_p.h
@@ -65,11 +65,11 @@ class QRingChunk
 {
 public:
     // initialization and cleanup
-    inline QRingChunk() Q_DECL_NOTHROW :
+    inline QRingChunk() noexcept :
         headOffset(0), tailOffset(0)
     {
     }
-    inline QRingChunk(const QRingChunk &other) Q_DECL_NOTHROW :
+    inline QRingChunk(const QRingChunk &other) noexcept :
         chunk(other.chunk), headOffset(other.headOffset), tailOffset(other.tailOffset)
     {
     }
@@ -77,30 +77,30 @@ public:
         chunk(alloc, Qt::Uninitialized), headOffset(0), tailOffset(0)
     {
     }
-    explicit inline QRingChunk(const QByteArray &qba) Q_DECL_NOTHROW :
+    explicit inline QRingChunk(const QByteArray &qba) noexcept :
         chunk(qba), headOffset(0), tailOffset(qba.size())
     {
     }
 
-    inline QRingChunk &operator=(const QRingChunk &other) Q_DECL_NOTHROW
+    inline QRingChunk &operator=(const QRingChunk &other) noexcept
     {
         chunk = other.chunk;
         headOffset = other.headOffset;
         tailOffset = other.tailOffset;
         return *this;
     }
-    inline QRingChunk(QRingChunk &&other) Q_DECL_NOTHROW :
+    inline QRingChunk(QRingChunk &&other) noexcept :
         chunk(other.chunk), headOffset(other.headOffset), tailOffset(other.tailOffset)
     {
         other.headOffset = other.tailOffset = 0;
     }
-    inline QRingChunk &operator=(QRingChunk &&other) Q_DECL_NOTHROW
+    inline QRingChunk &operator=(QRingChunk &&other) noexcept
     {
         swap(other);
         return *this;
     }
 
-    inline void swap(QRingChunk &other) Q_DECL_NOTHROW
+    inline void swap(QRingChunk &other) noexcept
     {
         chunk.swap(other.chunk);
         qSwap(headOffset, other.headOffset);
diff --git a/src/corelib/tools/qscopedpointer.h b/src/corelib/tools/qscopedpointer.h
index 2a4083466b..756e0aec79 100644
--- a/src/corelib/tools/qscopedpointer.h
+++ b/src/corelib/tools/qscopedpointer.h
@@ -97,7 +97,7 @@ class QScopedPointer
 {
     typedef T *QScopedPointer:: *RestrictedBool;
 public:
-    explicit QScopedPointer(T *p = nullptr) Q_DECL_NOTHROW : d(p)
+    explicit QScopedPointer(T *p = nullptr) noexcept : d(p)
     {
     }
 
@@ -113,12 +113,12 @@ public:
         return *d;
     }
 
-    T *operator->() const Q_DECL_NOTHROW
+    T *operator->() const noexcept
     {
         return d;
     }
 
-    bool operator!() const Q_DECL_NOTHROW
+    bool operator!() const noexcept
     {
         return !d;
     }
@@ -129,23 +129,23 @@ public:
         return isNull() ? nullptr : &QScopedPointer::d;
     }
 #else
-    operator RestrictedBool() const Q_DECL_NOTHROW
+    operator RestrictedBool() const noexcept
     {
         return isNull() ? nullptr : &QScopedPointer::d;
     }
 #endif
 
-    T *data() const Q_DECL_NOTHROW
+    T *data() const noexcept
     {
         return d;
     }
 
-    T *get() const Q_DECL_NOTHROW
+    T *get() const noexcept
     {
         return d;
     }
 
-    bool isNull() const Q_DECL_NOTHROW
+    bool isNull() const noexcept
     {
         return !d;
     }
@@ -159,14 +159,14 @@ public:
         Cleanup::cleanup(oldD);
     }
 
-    T *take() Q_DECL_NOTHROW
+    T *take() noexcept
     {
         T *oldD = d;
         d = nullptr;
         return oldD;
     }
 
-    void swap(QScopedPointer<T, Cleanup> &other) Q_DECL_NOTHROW
+    void swap(QScopedPointer<T, Cleanup> &other) noexcept
     {
         qSwap(d, other.d);
     }
@@ -181,43 +181,43 @@ private:
 };
 
 template <class T, class Cleanup>
-inline bool operator==(const QScopedPointer<T, Cleanup> &lhs, const QScopedPointer<T, Cleanup> &rhs) Q_DECL_NOTHROW
+inline bool operator==(const QScopedPointer<T, Cleanup> &lhs, const QScopedPointer<T, Cleanup> &rhs) noexcept
 {
     return lhs.data() == rhs.data();
 }
 
 template <class T, class Cleanup>
-inline bool operator!=(const QScopedPointer<T, Cleanup> &lhs, const QScopedPointer<T, Cleanup> &rhs) Q_DECL_NOTHROW
+inline bool operator!=(const QScopedPointer<T, Cleanup> &lhs, const QScopedPointer<T, Cleanup> &rhs) noexcept
 {
     return lhs.data() != rhs.data();
 }
 
 template <class T, class Cleanup>
-inline bool operator==(const QScopedPointer<T, Cleanup> &lhs, std::nullptr_t) Q_DECL_NOTHROW
+inline bool operator==(const QScopedPointer<T, Cleanup> &lhs, std::nullptr_t) noexcept
 {
     return lhs.isNull();
 }
 
 template <class T, class Cleanup>
-inline bool operator==(std::nullptr_t, const QScopedPointer<T, Cleanup> &rhs) Q_DECL_NOTHROW
+inline bool operator==(std::nullptr_t, const QScopedPointer<T, Cleanup> &rhs) noexcept
 {
     return rhs.isNull();
 }
 
 template <class T, class Cleanup>
-inline bool operator!=(const QScopedPointer<T, Cleanup> &lhs, std::nullptr_t) Q_DECL_NOTHROW
+inline bool operator!=(const QScopedPointer<T, Cleanup> &lhs, std::nullptr_t) noexcept
 {
     return !lhs.isNull();
 }
 
 template <class T, class Cleanup>
-inline bool operator!=(std::nullptr_t, const QScopedPointer<T, Cleanup> &rhs) Q_DECL_NOTHROW
+inline bool operator!=(std::nullptr_t, const QScopedPointer<T, Cleanup> &rhs) noexcept
 {
     return !rhs.isNull();
 }
 
 template <class T, class Cleanup>
-inline void swap(QScopedPointer<T, Cleanup> &p1, QScopedPointer<T, Cleanup> &p2) Q_DECL_NOTHROW
+inline void swap(QScopedPointer<T, Cleanup> &p1, QScopedPointer<T, Cleanup> &p2) noexcept
 { p1.swap(p2); }
 
 template <typename T, typename Cleanup = QScopedPointerArrayDeleter<T> >
@@ -244,7 +244,7 @@ public:
         return this->d[i];
     }
 
-    void swap(QScopedArrayPointer &other) Q_DECL_NOTHROW // prevent QScopedPointer <->QScopedArrayPointer swaps
+    void swap(QScopedArrayPointer &other) noexcept // prevent QScopedPointer <->QScopedArrayPointer swaps
     { QScopedPointer<T, Cleanup>::swap(other); }
 
 private:
@@ -263,7 +263,7 @@ private:
 };
 
 template <typename T, typename Cleanup>
-inline void swap(QScopedArrayPointer<T, Cleanup> &lhs, QScopedArrayPointer<T, Cleanup> &rhs) Q_DECL_NOTHROW
+inline void swap(QScopedArrayPointer<T, Cleanup> &lhs, QScopedArrayPointer<T, Cleanup> &rhs) noexcept
 { lhs.swap(rhs); }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/tools/qscopeguard.h b/src/corelib/tools/qscopeguard.h
index 0f61996eb6..41d0a6af68 100644
--- a/src/corelib/tools/qscopeguard.h
+++ b/src/corelib/tools/qscopeguard.h
@@ -58,7 +58,7 @@ Q_REQUIRED_RESULT
 QScopeGuard
 {
 public:
-    QScopeGuard(QScopeGuard &&other) Q_DECL_NOEXCEPT
+    QScopeGuard(QScopeGuard &&other) noexcept
         : m_func(std::move(other.m_func))
         , m_invoke(other.m_invoke)
     {
@@ -71,13 +71,13 @@ public:
             m_func();
     }
 
-    void dismiss() Q_DECL_NOEXCEPT
+    void dismiss() noexcept
     {
         m_invoke = false;
     }
 
 private:
-    explicit QScopeGuard(F f) Q_DECL_NOEXCEPT
+    explicit QScopeGuard(F f) noexcept
         : m_func(std::move(f))
     {
     }
diff --git a/src/corelib/tools/qset.h b/src/corelib/tools/qset.h
index 6640c8486d..d7fbc12b99 100644
--- a/src/corelib/tools/qset.h
+++ b/src/corelib/tools/qset.h
@@ -56,7 +56,7 @@ class QSet
     typedef QHash<T, QHashDummyValue> Hash;
 
 public:
-    inline QSet() Q_DECL_NOTHROW {}
+    inline QSet() noexcept {}
 #ifdef Q_COMPILER_INITIALIZER_LISTS
     inline QSet(std::initializer_list<T> list)
     {
@@ -68,7 +68,7 @@ public:
     // compiler-generated copy/move ctor/assignment operators are fine!
     // compiler-generated destructor is fine!
 
-    inline void swap(QSet<T> &other) Q_DECL_NOTHROW { q_hash.swap(other.q_hash); }
+    inline void swap(QSet<T> &other) noexcept { q_hash.swap(other.q_hash); }
 
     inline bool operator==(const QSet<T> &other) const
         { return q_hash == other.q_hash; }
@@ -176,20 +176,20 @@ public:
     typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
 
     inline iterator begin() { return q_hash.begin(); }
-    inline const_iterator begin() const Q_DECL_NOTHROW { return q_hash.begin(); }
-    inline const_iterator cbegin() const Q_DECL_NOTHROW { return q_hash.begin(); }
-    inline const_iterator constBegin() const Q_DECL_NOTHROW { return q_hash.constBegin(); }
+    inline const_iterator begin() const noexcept { return q_hash.begin(); }
+    inline const_iterator cbegin() const noexcept { return q_hash.begin(); }
+    inline const_iterator constBegin() const noexcept { return q_hash.constBegin(); }
     inline iterator end() { return q_hash.end(); }
-    inline const_iterator end() const Q_DECL_NOTHROW { return q_hash.end(); }
-    inline const_iterator cend() const Q_DECL_NOTHROW { return q_hash.end(); }
-    inline const_iterator constEnd() const Q_DECL_NOTHROW { return q_hash.constEnd(); }
+    inline const_iterator end() const noexcept { return q_hash.end(); }
+    inline const_iterator cend() const noexcept { return q_hash.end(); }
+    inline const_iterator constEnd() const noexcept { return q_hash.constEnd(); }
 
     reverse_iterator rbegin() { return reverse_iterator(end()); }
     reverse_iterator rend() { return reverse_iterator(begin()); }
-    const_reverse_iterator rbegin() const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    const_reverse_iterator rend() const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
-    const_reverse_iterator crbegin() const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    const_reverse_iterator crend() const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
+    const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
+    const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
+    const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
+    const_reverse_iterator crend() const noexcept { return const_reverse_iterator(begin()); }
 
     iterator erase(iterator i)
     { return erase(m2c(i)); }
@@ -252,14 +252,14 @@ public:
 private:
     Hash q_hash;
 
-    static const_iterator m2c(iterator it) Q_DECL_NOTHROW
+    static const_iterator m2c(iterator it) noexcept
     { return const_iterator(typename Hash::const_iterator(it.i.i)); }
 
     bool isValidIterator(const iterator &i) const
     {
         return q_hash.isValidIterator(reinterpret_cast<const typename Hash::iterator&>(i));
     }
-    bool isValidIterator(const const_iterator &i) const Q_DECL_NOTHROW
+    bool isValidIterator(const const_iterator &i) const noexcept
     {
         return q_hash.isValidIterator(reinterpret_cast<const typename Hash::const_iterator&>(i));
     }
diff --git a/src/corelib/tools/qshareddata.h b/src/corelib/tools/qshareddata.h
index 6930cb96a5..cbaa1aa3c4 100644
--- a/src/corelib/tools/qshareddata.h
+++ b/src/corelib/tools/qshareddata.h
@@ -88,7 +88,7 @@ public:
     inline QSharedDataPointer() { d = nullptr; }
     inline ~QSharedDataPointer() { if (d && !d->ref.deref()) delete d; }
 
-    explicit QSharedDataPointer(T *data) Q_DECL_NOTHROW;
+    explicit QSharedDataPointer(T *data) noexcept;
     inline QSharedDataPointer(const QSharedDataPointer<T> &o) : d(o.d) { if (d) d->ref.ref(); }
     inline QSharedDataPointer<T> & operator=(const QSharedDataPointer<T> &o) {
         if (o.d != d) {
@@ -113,8 +113,8 @@ public:
         return *this;
     }
 #ifdef Q_COMPILER_RVALUE_REFS
-    QSharedDataPointer(QSharedDataPointer &&o) Q_DECL_NOTHROW : d(o.d) { o.d = nullptr; }
-    inline QSharedDataPointer<T> &operator=(QSharedDataPointer<T> &&other) Q_DECL_NOTHROW
+    QSharedDataPointer(QSharedDataPointer &&o) noexcept : d(o.d) { o.d = nullptr; }
+    inline QSharedDataPointer<T> &operator=(QSharedDataPointer<T> &&other) noexcept
     {
         QSharedDataPointer moved(std::move(other));
         swap(moved);
@@ -124,7 +124,7 @@ public:
 
     inline bool operator!() const { return !d; }
 
-    inline void swap(QSharedDataPointer &other) Q_DECL_NOTHROW
+    inline void swap(QSharedDataPointer &other) noexcept
     { qSwap(d, other.d); }
 
 protected:
@@ -181,7 +181,7 @@ public:
     inline QExplicitlySharedDataPointer() { d = nullptr; }
     inline ~QExplicitlySharedDataPointer() { if (d && !d->ref.deref()) delete d; }
 
-    explicit QExplicitlySharedDataPointer(T *data) Q_DECL_NOTHROW;
+    explicit QExplicitlySharedDataPointer(T *data) noexcept;
     inline QExplicitlySharedDataPointer(const QExplicitlySharedDataPointer<T> &o) : d(o.d) { if (d) d->ref.ref(); }
 
     template<class X>
@@ -219,8 +219,8 @@ public:
         return *this;
     }
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QExplicitlySharedDataPointer(QExplicitlySharedDataPointer &&o) Q_DECL_NOTHROW : d(o.d) { o.d = nullptr; }
-    inline QExplicitlySharedDataPointer<T> &operator=(QExplicitlySharedDataPointer<T> &&other) Q_DECL_NOTHROW
+    inline QExplicitlySharedDataPointer(QExplicitlySharedDataPointer &&o) noexcept : d(o.d) { o.d = nullptr; }
+    inline QExplicitlySharedDataPointer<T> &operator=(QExplicitlySharedDataPointer<T> &&other) noexcept
     {
         QExplicitlySharedDataPointer moved(std::move(other));
         swap(moved);
@@ -230,7 +230,7 @@ public:
 
     inline bool operator!() const { return !d; }
 
-    inline void swap(QExplicitlySharedDataPointer &other) Q_DECL_NOTHROW
+    inline void swap(QExplicitlySharedDataPointer &other) noexcept
     { qSwap(d, other.d); }
 
 protected:
@@ -243,7 +243,7 @@ private:
 };
 
 template <class T>
-Q_INLINE_TEMPLATE QSharedDataPointer<T>::QSharedDataPointer(T *adata) Q_DECL_NOTHROW
+Q_INLINE_TEMPLATE QSharedDataPointer<T>::QSharedDataPointer(T *adata) noexcept
     : d(adata)
 { if (d) d->ref.ref(); }
 
@@ -280,7 +280,7 @@ Q_OUTOFLINE_TEMPLATE void QExplicitlySharedDataPointer<T>::detach_helper()
 }
 
 template <class T>
-Q_INLINE_TEMPLATE QExplicitlySharedDataPointer<T>::QExplicitlySharedDataPointer(T *adata) Q_DECL_NOTHROW
+Q_INLINE_TEMPLATE QExplicitlySharedDataPointer<T>::QExplicitlySharedDataPointer(T *adata) noexcept
     : d(adata)
 { if (d) d->ref.ref(); }
 
@@ -317,12 +317,12 @@ namespace std {
 QT_BEGIN_NAMESPACE
 
 template <class T>
-Q_INLINE_TEMPLATE uint qHash(const QSharedDataPointer<T> &ptr, uint seed = 0) Q_DECL_NOTHROW
+Q_INLINE_TEMPLATE uint qHash(const QSharedDataPointer<T> &ptr, uint seed = 0) noexcept
 {
     return qHash(ptr.data(), seed);
 }
 template <class T>
-Q_INLINE_TEMPLATE uint qHash(const QExplicitlySharedDataPointer<T> &ptr, uint seed = 0) Q_DECL_NOTHROW
+Q_INLINE_TEMPLATE uint qHash(const QExplicitlySharedDataPointer<T> &ptr, uint seed = 0) noexcept
 {
     return qHash(ptr.data(), seed);
 }
diff --git a/src/corelib/tools/qsharedpointer_impl.h b/src/corelib/tools/qsharedpointer_impl.h
index bccf8c5740..81d8dcd839 100644
--- a/src/corelib/tools/qsharedpointer_impl.h
+++ b/src/corelib/tools/qsharedpointer_impl.h
@@ -303,18 +303,18 @@ public:
     typedef const value_type &const_reference;
     typedef qptrdiff difference_type;
 
-    T *data() const Q_DECL_NOTHROW { return value; }
-    T *get() const Q_DECL_NOTHROW { return value; }
-    bool isNull() const Q_DECL_NOTHROW { return !data(); }
-    operator RestrictedBool() const Q_DECL_NOTHROW { return isNull() ? nullptr : &QSharedPointer::value; }
-    bool operator !() const Q_DECL_NOTHROW { return isNull(); }
+    T *data() const noexcept { return value; }
+    T *get() const noexcept { return value; }
+    bool isNull() const noexcept { return !data(); }
+    operator RestrictedBool() const noexcept { return isNull() ? nullptr : &QSharedPointer::value; }
+    bool operator !() const noexcept { return isNull(); }
     T &operator*() const { return *data(); }
-    T *operator->() const Q_DECL_NOTHROW { return data(); }
+    T *operator->() const noexcept { return data(); }
 
-    Q_DECL_CONSTEXPR QSharedPointer() Q_DECL_NOTHROW : value(nullptr), d(nullptr) { }
+    Q_DECL_CONSTEXPR QSharedPointer() noexcept : value(nullptr), d(nullptr) { }
     ~QSharedPointer() { deref(); }
 
-    Q_DECL_CONSTEXPR QSharedPointer(std::nullptr_t) Q_DECL_NOTHROW : value(nullptr), d(nullptr) { }
+    Q_DECL_CONSTEXPR QSharedPointer(std::nullptr_t) noexcept : value(nullptr), d(nullptr) { }
 
     template <class X>
     inline explicit QSharedPointer(X *ptr) : value(ptr) // noexcept
@@ -327,22 +327,22 @@ public:
     template <typename Deleter>
     QSharedPointer(std::nullptr_t, Deleter) : value(nullptr), d(nullptr) { }
 
-    QSharedPointer(const QSharedPointer &other) Q_DECL_NOTHROW : value(other.value), d(other.d)
+    QSharedPointer(const QSharedPointer &other) noexcept : value(other.value), d(other.d)
     { if (d) ref(); }
-    QSharedPointer &operator=(const QSharedPointer &other) Q_DECL_NOTHROW
+    QSharedPointer &operator=(const QSharedPointer &other) noexcept
     {
         QSharedPointer copy(other);
         swap(copy);
         return *this;
     }
 #ifdef Q_COMPILER_RVALUE_REFS
-    QSharedPointer(QSharedPointer &&other) Q_DECL_NOTHROW
+    QSharedPointer(QSharedPointer &&other) noexcept
         : value(other.value), d(other.d)
     {
         other.d = nullptr;
         other.value = nullptr;
     }
-    QSharedPointer &operator=(QSharedPointer &&other) Q_DECL_NOTHROW
+    QSharedPointer &operator=(QSharedPointer &&other) noexcept
     {
         QSharedPointer moved(std::move(other));
         swap(moved);
@@ -350,7 +350,7 @@ public:
     }
 
     template <class X>
-    QSharedPointer(QSharedPointer<X> &&other) Q_DECL_NOTHROW
+    QSharedPointer(QSharedPointer<X> &&other) noexcept
         : value(other.value), d(other.d)
     {
         other.d = nullptr;
@@ -358,7 +358,7 @@ public:
     }
 
     template <class X>
-    QSharedPointer &operator=(QSharedPointer<X> &&other) Q_DECL_NOTHROW
+    QSharedPointer &operator=(QSharedPointer<X> &&other) noexcept
     {
         QSharedPointer moved(std::move(other));
         swap(moved);
@@ -368,7 +368,7 @@ public:
 #endif
 
     template <class X>
-    QSharedPointer(const QSharedPointer<X> &other) Q_DECL_NOTHROW : value(other.value), d(other.d)
+    QSharedPointer(const QSharedPointer<X> &other) noexcept : value(other.value), d(other.d)
     { if (d) ref(); }
 
     template <class X>
@@ -456,9 +456,9 @@ public:
 private:
     explicit QSharedPointer(Qt::Initialization) {}
 
-    void deref() Q_DECL_NOTHROW
+    void deref() noexcept
     { deref(d); }
-    static void deref(Data *dd) Q_DECL_NOTHROW
+    static void deref(Data *dd) noexcept
     {
         if (!dd) return;
         if (!dd->strongref.deref()) {
@@ -499,7 +499,7 @@ private:
         enableSharedFromThis(ptr);
     }
 
-    void internalSwap(QSharedPointer &other) Q_DECL_NOTHROW
+    void internalSwap(QSharedPointer &other) noexcept
     {
         qSwap(d, other.d);
         qSwap(this->value, other.value);
@@ -512,7 +512,7 @@ public:
     template <class X> friend class QWeakPointer;
     template <class X, class Y> friend QSharedPointer<X> QtSharedPointer::copyAndSetPointer(X * ptr, const QSharedPointer<Y> &src);
 #endif
-    void ref() const Q_DECL_NOTHROW { d->weakref.ref(); d->strongref.ref(); }
+    void ref() const noexcept { d->weakref.ref(); d->strongref.ref(); }
 
     inline void internalSet(Data *o, T *actual)
     {
@@ -563,12 +563,12 @@ public:
     typedef const value_type &const_reference;
     typedef qptrdiff difference_type;
 
-    bool isNull() const Q_DECL_NOTHROW { return d == nullptr || d->strongref.load() == 0 || value == nullptr; }
-    operator RestrictedBool() const Q_DECL_NOTHROW { return isNull() ? nullptr : &QWeakPointer::value; }
-    bool operator !() const Q_DECL_NOTHROW { return isNull(); }
-    T *data() const Q_DECL_NOTHROW { return d == nullptr || d->strongref.load() == 0 ? nullptr : value; }
+    bool isNull() const noexcept { return d == nullptr || d->strongref.load() == 0 || value == nullptr; }
+    operator RestrictedBool() const noexcept { return isNull() ? nullptr : &QWeakPointer::value; }
+    bool operator !() const noexcept { return isNull(); }
+    T *data() const noexcept { return d == nullptr || d->strongref.load() == 0 ? nullptr : value; }
 
-    inline QWeakPointer() Q_DECL_NOTHROW : d(nullptr), value(nullptr) { }
+    inline QWeakPointer() noexcept : d(nullptr), value(nullptr) { }
     inline ~QWeakPointer() { if (d && !d->weakref.deref()) delete d; }
 
 #ifndef QT_NO_QOBJECT
@@ -586,26 +586,26 @@ public:
     { return *this = QWeakPointer(ptr); }
 #endif
 
-    QWeakPointer(const QWeakPointer &other) Q_DECL_NOTHROW : d(other.d), value(other.value)
+    QWeakPointer(const QWeakPointer &other) noexcept : d(other.d), value(other.value)
     { if (d) d->weakref.ref(); }
 #ifdef Q_COMPILER_RVALUE_REFS
-    QWeakPointer(QWeakPointer &&other) Q_DECL_NOTHROW
+    QWeakPointer(QWeakPointer &&other) noexcept
         : d(other.d), value(other.value)
     {
         other.d = nullptr;
         other.value = nullptr;
     }
-    QWeakPointer &operator=(QWeakPointer &&other) Q_DECL_NOTHROW
+    QWeakPointer &operator=(QWeakPointer &&other) noexcept
     { QWeakPointer moved(std::move(other)); swap(moved); return *this; }
 #endif
-    QWeakPointer &operator=(const QWeakPointer &other) Q_DECL_NOTHROW
+    QWeakPointer &operator=(const QWeakPointer &other) noexcept
     {
         QWeakPointer copy(other);
         swap(copy);
         return *this;
     }
 
-    void swap(QWeakPointer &other) Q_DECL_NOTHROW
+    void swap(QWeakPointer &other) noexcept
     {
         qSwap(this->d, other.d);
         qSwap(this->value, other.value);
@@ -633,11 +633,11 @@ public:
     }
 
     template <class X>
-    bool operator==(const QWeakPointer<X> &o) const Q_DECL_NOTHROW
+    bool operator==(const QWeakPointer<X> &o) const noexcept
     { return d == o.d && value == static_cast<const T *>(o.value); }
 
     template <class X>
-    bool operator!=(const QWeakPointer<X> &o) const Q_DECL_NOTHROW
+    bool operator!=(const QWeakPointer<X> &o) const noexcept
     { return !(*this == o); }
 
     template <class X>
@@ -653,11 +653,11 @@ public:
     }
 
     template <class X>
-    bool operator==(const QSharedPointer<X> &o) const Q_DECL_NOTHROW
+    bool operator==(const QSharedPointer<X> &o) const noexcept
     { return d == o.d; }
 
     template <class X>
-    bool operator!=(const QSharedPointer<X> &o) const Q_DECL_NOTHROW
+    bool operator!=(const QSharedPointer<X> &o) const noexcept
     { return !(*this == o); }
 
     inline void clear() { *this = QWeakPointer(); }
@@ -739,92 +739,92 @@ public:
 // operator== and operator!=
 //
 template <class T, class X>
-bool operator==(const QSharedPointer<T> &ptr1, const QSharedPointer<X> &ptr2) Q_DECL_NOTHROW
+bool operator==(const QSharedPointer<T> &ptr1, const QSharedPointer<X> &ptr2) noexcept
 {
     return ptr1.data() == ptr2.data();
 }
 template <class T, class X>
-bool operator!=(const QSharedPointer<T> &ptr1, const QSharedPointer<X> &ptr2) Q_DECL_NOTHROW
+bool operator!=(const QSharedPointer<T> &ptr1, const QSharedPointer<X> &ptr2) noexcept
 {
     return ptr1.data() != ptr2.data();
 }
 
 template <class T, class X>
-bool operator==(const QSharedPointer<T> &ptr1, const X *ptr2) Q_DECL_NOTHROW
+bool operator==(const QSharedPointer<T> &ptr1, const X *ptr2) noexcept
 {
     return ptr1.data() == ptr2;
 }
 template <class T, class X>
-bool operator==(const T *ptr1, const QSharedPointer<X> &ptr2) Q_DECL_NOTHROW
+bool operator==(const T *ptr1, const QSharedPointer<X> &ptr2) noexcept
 {
     return ptr1 == ptr2.data();
 }
 template <class T, class X>
-bool operator!=(const QSharedPointer<T> &ptr1, const X *ptr2) Q_DECL_NOTHROW
+bool operator!=(const QSharedPointer<T> &ptr1, const X *ptr2) noexcept
 {
     return !(ptr1 == ptr2);
 }
 template <class T, class X>
-bool operator!=(const T *ptr1, const QSharedPointer<X> &ptr2) Q_DECL_NOTHROW
+bool operator!=(const T *ptr1, const QSharedPointer<X> &ptr2) noexcept
 {
     return !(ptr2 == ptr1);
 }
 
 template <class T, class X>
-bool operator==(const QSharedPointer<T> &ptr1, const QWeakPointer<X> &ptr2) Q_DECL_NOTHROW
+bool operator==(const QSharedPointer<T> &ptr1, const QWeakPointer<X> &ptr2) noexcept
 {
     return ptr2 == ptr1;
 }
 template <class T, class X>
-bool operator!=(const QSharedPointer<T> &ptr1, const QWeakPointer<X> &ptr2) Q_DECL_NOTHROW
+bool operator!=(const QSharedPointer<T> &ptr1, const QWeakPointer<X> &ptr2) noexcept
 {
     return ptr2 != ptr1;
 }
 
 template<class T>
-inline bool operator==(const QSharedPointer<T> &lhs, std::nullptr_t) Q_DECL_NOTHROW
+inline bool operator==(const QSharedPointer<T> &lhs, std::nullptr_t) noexcept
 {
     return lhs.isNull();
 }
 
 template<class T>
-inline bool operator!=(const QSharedPointer<T> &lhs, std::nullptr_t) Q_DECL_NOTHROW
+inline bool operator!=(const QSharedPointer<T> &lhs, std::nullptr_t) noexcept
 {
     return !lhs.isNull();
 }
 
 template<class T>
-inline bool operator==(std::nullptr_t, const QSharedPointer<T> &rhs) Q_DECL_NOTHROW
+inline bool operator==(std::nullptr_t, const QSharedPointer<T> &rhs) noexcept
 {
     return rhs.isNull();
 }
 
 template<class T>
-inline bool operator!=(std::nullptr_t, const QSharedPointer<T> &rhs) Q_DECL_NOTHROW
+inline bool operator!=(std::nullptr_t, const QSharedPointer<T> &rhs) noexcept
 {
     return !rhs.isNull();
 }
 
 template<class T>
-inline bool operator==(const QWeakPointer<T> &lhs, std::nullptr_t) Q_DECL_NOTHROW
+inline bool operator==(const QWeakPointer<T> &lhs, std::nullptr_t) noexcept
 {
     return lhs.isNull();
 }
 
 template<class T>
-inline bool operator!=(const QWeakPointer<T> &lhs, std::nullptr_t) Q_DECL_NOTHROW
+inline bool operator!=(const QWeakPointer<T> &lhs, std::nullptr_t) noexcept
 {
     return !lhs.isNull();
 }
 
 template<class T>
-inline bool operator==(std::nullptr_t, const QWeakPointer<T> &rhs) Q_DECL_NOTHROW
+inline bool operator==(std::nullptr_t, const QWeakPointer<T> &rhs) noexcept
 {
     return rhs.isNull();
 }
 
 template<class T>
-inline bool operator!=(std::nullptr_t, const QWeakPointer<T> &rhs) Q_DECL_NOTHROW
+inline bool operator!=(std::nullptr_t, const QWeakPointer<T> &rhs) noexcept
 {
     return !rhs.isNull();
 }
diff --git a/src/corelib/tools/qsize.cpp b/src/corelib/tools/qsize.cpp
index 3e97947ad2..fe508ad459 100644
--- a/src/corelib/tools/qsize.cpp
+++ b/src/corelib/tools/qsize.cpp
@@ -163,7 +163,7 @@ QT_BEGIN_NAMESPACE
     \sa setWidth(), setHeight(), transposed()
 */
 
-void QSize::transpose() Q_DECL_NOTHROW
+void QSize::transpose() noexcept
 {
     qSwap(wd, ht);
 }
@@ -222,7 +222,7 @@ void QSize::transpose() Q_DECL_NOTHROW
     Return a size scaled to a rectangle with the given size \a s,
     according to the specified \a mode.
 */
-QSize QSize::scaled(const QSize &s, Qt::AspectRatioMode mode) const Q_DECL_NOTHROW
+QSize QSize::scaled(const QSize &s, Qt::AspectRatioMode mode) const noexcept
 {
     if (mode == Qt::IgnoreAspectRatio || wd == 0 || ht == 0) {
         return s;
@@ -594,7 +594,7 @@ QDebug operator<<(QDebug dbg, const QSize &s)
     \sa setWidth(), setHeight(), transposed()
 */
 
-void QSizeF::transpose() Q_DECL_NOTHROW
+void QSizeF::transpose() noexcept
 {
     qSwap(wd, ht);
 }
@@ -653,7 +653,7 @@ void QSizeF::transpose() Q_DECL_NOTHROW
     Returns a size scaled to a rectangle with the given size \a s,
     according to the specified \a mode.
 */
-QSizeF QSizeF::scaled(const QSizeF &s, Qt::AspectRatioMode mode) const Q_DECL_NOTHROW
+QSizeF QSizeF::scaled(const QSizeF &s, Qt::AspectRatioMode mode) const noexcept
 {
     if (mode == Qt::IgnoreAspectRatio || qIsNull(wd) || qIsNull(ht)) {
         return s;
diff --git a/src/corelib/tools/qsize.h b/src/corelib/tools/qsize.h
index bb29dca7c4..4114609856 100644
--- a/src/corelib/tools/qsize.h
+++ b/src/corelib/tools/qsize.h
@@ -52,46 +52,46 @@ QT_BEGIN_NAMESPACE
 class Q_CORE_EXPORT QSize
 {
 public:
-    Q_DECL_CONSTEXPR QSize() Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QSize(int w, int h) Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline bool isNull() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline bool isEmpty() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline bool isValid() const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline int width() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline int height() const Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setWidth(int w) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setHeight(int h) Q_DECL_NOTHROW;
-    void transpose() Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSize transposed() const Q_DECL_NOTHROW;
-
-    inline void scale(int w, int h, Qt::AspectRatioMode mode) Q_DECL_NOTHROW;
-    inline void scale(const QSize &s, Qt::AspectRatioMode mode) Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT QSize scaled(int w, int h, Qt::AspectRatioMode mode) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT QSize scaled(const QSize &s, Qt::AspectRatioMode mode) const Q_DECL_NOTHROW;
-
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSize expandedTo(const QSize &) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSize boundedTo(const QSize &) const Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline int &rwidth() Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline int &rheight() Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline QSize &operator+=(const QSize &) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline QSize &operator-=(const QSize &) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline QSize &operator*=(qreal c) Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR QSize() noexcept;
+    Q_DECL_CONSTEXPR QSize(int w, int h) noexcept;
+
+    Q_DECL_CONSTEXPR inline bool isNull() const noexcept;
+    Q_DECL_CONSTEXPR inline bool isEmpty() const noexcept;
+    Q_DECL_CONSTEXPR inline bool isValid() const noexcept;
+
+    Q_DECL_CONSTEXPR inline int width() const noexcept;
+    Q_DECL_CONSTEXPR inline int height() const noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setWidth(int w) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setHeight(int h) noexcept;
+    void transpose() noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSize transposed() const noexcept;
+
+    inline void scale(int w, int h, Qt::AspectRatioMode mode) noexcept;
+    inline void scale(const QSize &s, Qt::AspectRatioMode mode) noexcept;
+    Q_REQUIRED_RESULT QSize scaled(int w, int h, Qt::AspectRatioMode mode) const noexcept;
+    Q_REQUIRED_RESULT QSize scaled(const QSize &s, Qt::AspectRatioMode mode) const noexcept;
+
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSize expandedTo(const QSize &) const noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSize boundedTo(const QSize &) const noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline int &rwidth() noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline int &rheight() noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline QSize &operator+=(const QSize &) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline QSize &operator-=(const QSize &) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline QSize &operator*=(qreal c) noexcept;
     inline QSize &operator/=(qreal c);
 
-    friend inline Q_DECL_CONSTEXPR bool operator==(const QSize &, const QSize &) Q_DECL_NOTHROW;
-    friend inline Q_DECL_CONSTEXPR bool operator!=(const QSize &, const QSize &) Q_DECL_NOTHROW;
-    friend inline Q_DECL_CONSTEXPR const QSize operator+(const QSize &, const QSize &) Q_DECL_NOTHROW;
-    friend inline Q_DECL_CONSTEXPR const QSize operator-(const QSize &, const QSize &) Q_DECL_NOTHROW;
-    friend inline Q_DECL_CONSTEXPR const QSize operator*(const QSize &, qreal) Q_DECL_NOTHROW;
-    friend inline Q_DECL_CONSTEXPR const QSize operator*(qreal, const QSize &) Q_DECL_NOTHROW;
+    friend inline Q_DECL_CONSTEXPR bool operator==(const QSize &, const QSize &) noexcept;
+    friend inline Q_DECL_CONSTEXPR bool operator!=(const QSize &, const QSize &) noexcept;
+    friend inline Q_DECL_CONSTEXPR const QSize operator+(const QSize &, const QSize &) noexcept;
+    friend inline Q_DECL_CONSTEXPR const QSize operator-(const QSize &, const QSize &) noexcept;
+    friend inline Q_DECL_CONSTEXPR const QSize operator*(const QSize &, qreal) noexcept;
+    friend inline Q_DECL_CONSTEXPR const QSize operator*(qreal, const QSize &) noexcept;
     friend inline const QSize operator/(const QSize &, qreal);
 
 #if defined(Q_OS_DARWIN) || defined(Q_QDOC)
-    Q_REQUIRED_RESULT CGSize toCGSize() const Q_DECL_NOTHROW;
+    Q_REQUIRED_RESULT CGSize toCGSize() const noexcept;
 #endif
 
 private:
@@ -114,74 +114,74 @@ Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QSize &);
   QSize inline functions
  *****************************************************************************/
 
-Q_DECL_CONSTEXPR inline QSize::QSize() Q_DECL_NOTHROW : wd(-1), ht(-1) {}
+Q_DECL_CONSTEXPR inline QSize::QSize() noexcept : wd(-1), ht(-1) {}
 
-Q_DECL_CONSTEXPR inline QSize::QSize(int w, int h) Q_DECL_NOTHROW : wd(w), ht(h) {}
+Q_DECL_CONSTEXPR inline QSize::QSize(int w, int h) noexcept : wd(w), ht(h) {}
 
-Q_DECL_CONSTEXPR inline bool QSize::isNull() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QSize::isNull() const noexcept
 { return wd==0 && ht==0; }
 
-Q_DECL_CONSTEXPR inline bool QSize::isEmpty() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QSize::isEmpty() const noexcept
 { return wd<1 || ht<1; }
 
-Q_DECL_CONSTEXPR inline bool QSize::isValid() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QSize::isValid() const noexcept
 { return wd>=0 && ht>=0; }
 
-Q_DECL_CONSTEXPR inline int QSize::width() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QSize::width() const noexcept
 { return wd; }
 
-Q_DECL_CONSTEXPR inline int QSize::height() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int QSize::height() const noexcept
 { return ht; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QSize::setWidth(int w) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QSize::setWidth(int w) noexcept
 { wd = w; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QSize::setHeight(int h) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QSize::setHeight(int h) noexcept
 { ht = h; }
 
-Q_DECL_CONSTEXPR inline QSize QSize::transposed() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QSize QSize::transposed() const noexcept
 { return QSize(ht, wd); }
 
-inline void QSize::scale(int w, int h, Qt::AspectRatioMode mode) Q_DECL_NOTHROW
+inline void QSize::scale(int w, int h, Qt::AspectRatioMode mode) noexcept
 { scale(QSize(w, h), mode); }
 
-inline void QSize::scale(const QSize &s, Qt::AspectRatioMode mode) Q_DECL_NOTHROW
+inline void QSize::scale(const QSize &s, Qt::AspectRatioMode mode) noexcept
 { *this = scaled(s, mode); }
 
-inline QSize QSize::scaled(int w, int h, Qt::AspectRatioMode mode) const Q_DECL_NOTHROW
+inline QSize QSize::scaled(int w, int h, Qt::AspectRatioMode mode) const noexcept
 { return scaled(QSize(w, h), mode); }
 
-Q_DECL_RELAXED_CONSTEXPR inline int &QSize::rwidth() Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline int &QSize::rwidth() noexcept
 { return wd; }
 
-Q_DECL_RELAXED_CONSTEXPR inline int &QSize::rheight() Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline int &QSize::rheight() noexcept
 { return ht; }
 
-Q_DECL_RELAXED_CONSTEXPR inline QSize &QSize::operator+=(const QSize &s) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QSize &QSize::operator+=(const QSize &s) noexcept
 { wd+=s.wd; ht+=s.ht; return *this; }
 
-Q_DECL_RELAXED_CONSTEXPR inline QSize &QSize::operator-=(const QSize &s) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QSize &QSize::operator-=(const QSize &s) noexcept
 { wd-=s.wd; ht-=s.ht; return *this; }
 
-Q_DECL_RELAXED_CONSTEXPR inline QSize &QSize::operator*=(qreal c) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QSize &QSize::operator*=(qreal c) noexcept
 { wd = qRound(wd*c); ht = qRound(ht*c); return *this; }
 
-Q_DECL_CONSTEXPR inline bool operator==(const QSize &s1, const QSize &s2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator==(const QSize &s1, const QSize &s2) noexcept
 { return s1.wd == s2.wd && s1.ht == s2.ht; }
 
-Q_DECL_CONSTEXPR inline bool operator!=(const QSize &s1, const QSize &s2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator!=(const QSize &s1, const QSize &s2) noexcept
 { return s1.wd != s2.wd || s1.ht != s2.ht; }
 
-Q_DECL_CONSTEXPR inline const QSize operator+(const QSize & s1, const QSize & s2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline const QSize operator+(const QSize & s1, const QSize & s2) noexcept
 { return QSize(s1.wd+s2.wd, s1.ht+s2.ht); }
 
-Q_DECL_CONSTEXPR inline const QSize operator-(const QSize &s1, const QSize &s2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline const QSize operator-(const QSize &s1, const QSize &s2) noexcept
 { return QSize(s1.wd-s2.wd, s1.ht-s2.ht); }
 
-Q_DECL_CONSTEXPR inline const QSize operator*(const QSize &s, qreal c) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline const QSize operator*(const QSize &s, qreal c) noexcept
 { return QSize(qRound(s.wd*c), qRound(s.ht*c)); }
 
-Q_DECL_CONSTEXPR inline const QSize operator*(qreal c, const QSize &s) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline const QSize operator*(qreal c, const QSize &s) noexcept
 { return QSize(qRound(s.wd*c), qRound(s.ht*c)); }
 
 inline QSize &QSize::operator/=(qreal c)
@@ -197,12 +197,12 @@ inline const QSize operator/(const QSize &s, qreal c)
     return QSize(qRound(s.wd/c), qRound(s.ht/c));
 }
 
-Q_DECL_CONSTEXPR inline QSize QSize::expandedTo(const QSize & otherSize) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QSize QSize::expandedTo(const QSize & otherSize) const noexcept
 {
     return QSize(qMax(wd,otherSize.wd), qMax(ht,otherSize.ht));
 }
 
-Q_DECL_CONSTEXPR inline QSize QSize::boundedTo(const QSize & otherSize) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QSize QSize::boundedTo(const QSize & otherSize) const noexcept
 {
     return QSize(qMin(wd,otherSize.wd), qMin(ht,otherSize.ht));
 }
@@ -215,50 +215,50 @@ Q_CORE_EXPORT QDebug operator<<(QDebug, const QSize &);
 class Q_CORE_EXPORT QSizeF
 {
 public:
-    Q_DECL_CONSTEXPR QSizeF() Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QSizeF(const QSize &sz) Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR QSizeF(qreal w, qreal h) Q_DECL_NOTHROW;
-
-    inline bool isNull() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline bool isEmpty() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline bool isValid() const Q_DECL_NOTHROW;
-
-    Q_DECL_CONSTEXPR inline qreal width() const Q_DECL_NOTHROW;
-    Q_DECL_CONSTEXPR inline qreal height() const Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setWidth(qreal w) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline void setHeight(qreal h) Q_DECL_NOTHROW;
-    void transpose() Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSizeF transposed() const Q_DECL_NOTHROW;
-
-    inline void scale(qreal w, qreal h, Qt::AspectRatioMode mode) Q_DECL_NOTHROW;
-    inline void scale(const QSizeF &s, Qt::AspectRatioMode mode) Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT QSizeF scaled(qreal w, qreal h, Qt::AspectRatioMode mode) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT QSizeF scaled(const QSizeF &s, Qt::AspectRatioMode mode) const Q_DECL_NOTHROW;
-
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSizeF expandedTo(const QSizeF &) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSizeF boundedTo(const QSizeF &) const Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline qreal &rwidth() Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline qreal &rheight() Q_DECL_NOTHROW;
-
-    Q_DECL_RELAXED_CONSTEXPR inline QSizeF &operator+=(const QSizeF &) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline QSizeF &operator-=(const QSizeF &) Q_DECL_NOTHROW;
-    Q_DECL_RELAXED_CONSTEXPR inline QSizeF &operator*=(qreal c) Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR QSizeF() noexcept;
+    Q_DECL_CONSTEXPR QSizeF(const QSize &sz) noexcept;
+    Q_DECL_CONSTEXPR QSizeF(qreal w, qreal h) noexcept;
+
+    inline bool isNull() const noexcept;
+    Q_DECL_CONSTEXPR inline bool isEmpty() const noexcept;
+    Q_DECL_CONSTEXPR inline bool isValid() const noexcept;
+
+    Q_DECL_CONSTEXPR inline qreal width() const noexcept;
+    Q_DECL_CONSTEXPR inline qreal height() const noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setWidth(qreal w) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline void setHeight(qreal h) noexcept;
+    void transpose() noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSizeF transposed() const noexcept;
+
+    inline void scale(qreal w, qreal h, Qt::AspectRatioMode mode) noexcept;
+    inline void scale(const QSizeF &s, Qt::AspectRatioMode mode) noexcept;
+    Q_REQUIRED_RESULT QSizeF scaled(qreal w, qreal h, Qt::AspectRatioMode mode) const noexcept;
+    Q_REQUIRED_RESULT QSizeF scaled(const QSizeF &s, Qt::AspectRatioMode mode) const noexcept;
+
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSizeF expandedTo(const QSizeF &) const noexcept;
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline QSizeF boundedTo(const QSizeF &) const noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline qreal &rwidth() noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline qreal &rheight() noexcept;
+
+    Q_DECL_RELAXED_CONSTEXPR inline QSizeF &operator+=(const QSizeF &) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline QSizeF &operator-=(const QSizeF &) noexcept;
+    Q_DECL_RELAXED_CONSTEXPR inline QSizeF &operator*=(qreal c) noexcept;
     inline QSizeF &operator/=(qreal c);
 
-    friend Q_DECL_CONSTEXPR inline bool operator==(const QSizeF &, const QSizeF &) Q_DECL_NOTHROW;
-    friend Q_DECL_CONSTEXPR inline bool operator!=(const QSizeF &, const QSizeF &) Q_DECL_NOTHROW;
-    friend Q_DECL_CONSTEXPR inline const QSizeF operator+(const QSizeF &, const QSizeF &) Q_DECL_NOTHROW;
-    friend Q_DECL_CONSTEXPR inline const QSizeF operator-(const QSizeF &, const QSizeF &) Q_DECL_NOTHROW;
-    friend Q_DECL_CONSTEXPR inline const QSizeF operator*(const QSizeF &, qreal) Q_DECL_NOTHROW;
-    friend Q_DECL_CONSTEXPR inline const QSizeF operator*(qreal, const QSizeF &) Q_DECL_NOTHROW;
+    friend Q_DECL_CONSTEXPR inline bool operator==(const QSizeF &, const QSizeF &) noexcept;
+    friend Q_DECL_CONSTEXPR inline bool operator!=(const QSizeF &, const QSizeF &) noexcept;
+    friend Q_DECL_CONSTEXPR inline const QSizeF operator+(const QSizeF &, const QSizeF &) noexcept;
+    friend Q_DECL_CONSTEXPR inline const QSizeF operator-(const QSizeF &, const QSizeF &) noexcept;
+    friend Q_DECL_CONSTEXPR inline const QSizeF operator*(const QSizeF &, qreal) noexcept;
+    friend Q_DECL_CONSTEXPR inline const QSizeF operator*(qreal, const QSizeF &) noexcept;
     friend inline const QSizeF operator/(const QSizeF &, qreal);
 
-    Q_DECL_CONSTEXPR inline QSize toSize() const Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR inline QSize toSize() const noexcept;
 
 #if defined(Q_OS_DARWIN) || defined(Q_QDOC)
-    Q_REQUIRED_RESULT static QSizeF fromCGSize(CGSize size) Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT CGSize toCGSize() const Q_DECL_NOTHROW;
+    Q_REQUIRED_RESULT static QSizeF fromCGSize(CGSize size) noexcept;
+    Q_REQUIRED_RESULT CGSize toCGSize() const noexcept;
 #endif
 
 private:
@@ -282,76 +282,76 @@ Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QSizeF &);
   QSizeF inline functions
  *****************************************************************************/
 
-Q_DECL_CONSTEXPR inline QSizeF::QSizeF() Q_DECL_NOTHROW : wd(-1.), ht(-1.) {}
+Q_DECL_CONSTEXPR inline QSizeF::QSizeF() noexcept : wd(-1.), ht(-1.) {}
 
-Q_DECL_CONSTEXPR inline QSizeF::QSizeF(const QSize &sz) Q_DECL_NOTHROW : wd(sz.width()), ht(sz.height()) {}
+Q_DECL_CONSTEXPR inline QSizeF::QSizeF(const QSize &sz) noexcept : wd(sz.width()), ht(sz.height()) {}
 
-Q_DECL_CONSTEXPR inline QSizeF::QSizeF(qreal w, qreal h) Q_DECL_NOTHROW : wd(w), ht(h) {}
+Q_DECL_CONSTEXPR inline QSizeF::QSizeF(qreal w, qreal h) noexcept : wd(w), ht(h) {}
 
-inline bool QSizeF::isNull() const Q_DECL_NOTHROW
+inline bool QSizeF::isNull() const noexcept
 { return qIsNull(wd) && qIsNull(ht); }
 
-Q_DECL_CONSTEXPR inline bool QSizeF::isEmpty() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QSizeF::isEmpty() const noexcept
 { return wd <= 0. || ht <= 0.; }
 
-Q_DECL_CONSTEXPR inline bool QSizeF::isValid() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool QSizeF::isValid() const noexcept
 { return wd >= 0. && ht >= 0.; }
 
-Q_DECL_CONSTEXPR inline qreal QSizeF::width() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline qreal QSizeF::width() const noexcept
 { return wd; }
 
-Q_DECL_CONSTEXPR inline qreal QSizeF::height() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline qreal QSizeF::height() const noexcept
 { return ht; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QSizeF::setWidth(qreal w) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QSizeF::setWidth(qreal w) noexcept
 { wd = w; }
 
-Q_DECL_RELAXED_CONSTEXPR inline void QSizeF::setHeight(qreal h) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline void QSizeF::setHeight(qreal h) noexcept
 { ht = h; }
 
-Q_DECL_CONSTEXPR inline QSizeF QSizeF::transposed() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QSizeF QSizeF::transposed() const noexcept
 { return QSizeF(ht, wd); }
 
-inline void QSizeF::scale(qreal w, qreal h, Qt::AspectRatioMode mode) Q_DECL_NOTHROW
+inline void QSizeF::scale(qreal w, qreal h, Qt::AspectRatioMode mode) noexcept
 { scale(QSizeF(w, h), mode); }
 
-inline void QSizeF::scale(const QSizeF &s, Qt::AspectRatioMode mode) Q_DECL_NOTHROW
+inline void QSizeF::scale(const QSizeF &s, Qt::AspectRatioMode mode) noexcept
 { *this = scaled(s, mode); }
 
-inline QSizeF QSizeF::scaled(qreal w, qreal h, Qt::AspectRatioMode mode) const Q_DECL_NOTHROW
+inline QSizeF QSizeF::scaled(qreal w, qreal h, Qt::AspectRatioMode mode) const noexcept
 { return scaled(QSizeF(w, h), mode); }
 
-Q_DECL_RELAXED_CONSTEXPR inline qreal &QSizeF::rwidth() Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline qreal &QSizeF::rwidth() noexcept
 { return wd; }
 
-Q_DECL_RELAXED_CONSTEXPR inline qreal &QSizeF::rheight() Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline qreal &QSizeF::rheight() noexcept
 { return ht; }
 
-Q_DECL_RELAXED_CONSTEXPR inline QSizeF &QSizeF::operator+=(const QSizeF &s) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QSizeF &QSizeF::operator+=(const QSizeF &s) noexcept
 { wd += s.wd; ht += s.ht; return *this; }
 
-Q_DECL_RELAXED_CONSTEXPR inline QSizeF &QSizeF::operator-=(const QSizeF &s) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QSizeF &QSizeF::operator-=(const QSizeF &s) noexcept
 { wd -= s.wd; ht -= s.ht; return *this; }
 
-Q_DECL_RELAXED_CONSTEXPR inline QSizeF &QSizeF::operator*=(qreal c) Q_DECL_NOTHROW
+Q_DECL_RELAXED_CONSTEXPR inline QSizeF &QSizeF::operator*=(qreal c) noexcept
 { wd *= c; ht *= c; return *this; }
 
-Q_DECL_CONSTEXPR inline bool operator==(const QSizeF &s1, const QSizeF &s2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator==(const QSizeF &s1, const QSizeF &s2) noexcept
 { return qFuzzyCompare(s1.wd, s2.wd) && qFuzzyCompare(s1.ht, s2.ht); }
 
-Q_DECL_CONSTEXPR inline bool operator!=(const QSizeF &s1, const QSizeF &s2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator!=(const QSizeF &s1, const QSizeF &s2) noexcept
 { return !qFuzzyCompare(s1.wd, s2.wd) || !qFuzzyCompare(s1.ht, s2.ht); }
 
-Q_DECL_CONSTEXPR inline const QSizeF operator+(const QSizeF & s1, const QSizeF & s2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline const QSizeF operator+(const QSizeF & s1, const QSizeF & s2) noexcept
 { return QSizeF(s1.wd+s2.wd, s1.ht+s2.ht); }
 
-Q_DECL_CONSTEXPR inline const QSizeF operator-(const QSizeF &s1, const QSizeF &s2) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline const QSizeF operator-(const QSizeF &s1, const QSizeF &s2) noexcept
 { return QSizeF(s1.wd-s2.wd, s1.ht-s2.ht); }
 
-Q_DECL_CONSTEXPR inline const QSizeF operator*(const QSizeF &s, qreal c) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline const QSizeF operator*(const QSizeF &s, qreal c) noexcept
 { return QSizeF(s.wd*c, s.ht*c); }
 
-Q_DECL_CONSTEXPR inline const QSizeF operator*(qreal c, const QSizeF &s) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline const QSizeF operator*(qreal c, const QSizeF &s) noexcept
 { return QSizeF(s.wd*c, s.ht*c); }
 
 inline QSizeF &QSizeF::operator/=(qreal c)
@@ -367,17 +367,17 @@ inline const QSizeF operator/(const QSizeF &s, qreal c)
     return QSizeF(s.wd/c, s.ht/c);
 }
 
-Q_DECL_CONSTEXPR inline QSizeF QSizeF::expandedTo(const QSizeF & otherSize) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QSizeF QSizeF::expandedTo(const QSizeF & otherSize) const noexcept
 {
     return QSizeF(qMax(wd,otherSize.wd), qMax(ht,otherSize.ht));
 }
 
-Q_DECL_CONSTEXPR inline QSizeF QSizeF::boundedTo(const QSizeF & otherSize) const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QSizeF QSizeF::boundedTo(const QSizeF & otherSize) const noexcept
 {
     return QSizeF(qMin(wd,otherSize.wd), qMin(ht,otherSize.ht));
 }
 
-Q_DECL_CONSTEXPR inline QSize QSizeF::toSize() const Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline QSize QSizeF::toSize() const noexcept
 {
     return QSize(qRound(wd), qRound(ht));
 }
diff --git a/src/corelib/tools/qstack.h b/src/corelib/tools/qstack.h
index bf04935b50..e59212aa2a 100644
--- a/src/corelib/tools/qstack.h
+++ b/src/corelib/tools/qstack.h
@@ -50,7 +50,7 @@ class QStack : public QVector<T>
 {
 public:
     // compiler-generated special member functions are fine!
-    inline void swap(QStack<T> &other) Q_DECL_NOTHROW { QVector<T>::swap(other); } // prevent QVector<->QStack swaps
+    inline void swap(QStack<T> &other) noexcept { QVector<T>::swap(other); } // prevent QVector<->QStack swaps
     inline void push(const T &t) { QVector<T>::append(t); }
     T pop();
     T &top();
diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp
index 65519d1f98..74debd8cfa 100644
--- a/src/corelib/tools/qstring.cpp
+++ b/src/corelib/tools/qstring.cpp
@@ -155,7 +155,7 @@ static inline bool qt_ends_with(QStringView haystack, QStringView needle, Qt::Ca
 static inline bool qt_ends_with(QStringView haystack, QLatin1String needle, Qt::CaseSensitivity cs);
 static inline bool qt_ends_with(QStringView haystack, QChar needle, Qt::CaseSensitivity cs);
 
-qsizetype QtPrivate::qustrlen(const ushort *str) Q_DECL_NOTHROW
+qsizetype QtPrivate::qustrlen(const ushort *str) noexcept
 {
     qsizetype result = 0;
 
@@ -453,7 +453,7 @@ static Q_ALWAYS_INLINE __m128i mm_load8_zero_extend(const void *ptr)
 
 // Note: ptr on output may be off by one and point to a preceding US-ASCII
 // character. Usually harmless.
-bool qt_is_ascii(const char *&ptr, const char *end) Q_DECL_NOTHROW
+bool qt_is_ascii(const char *&ptr, const char *end) noexcept
 {
 #if defined(__SSE2__)
     // Testing for the high bit can be done efficiently with just PMOVMSKB
@@ -509,7 +509,7 @@ bool qt_is_ascii(const char *&ptr, const char *end) Q_DECL_NOTHROW
     return true;
 }
 
-bool QtPrivate::isAscii(QLatin1String s) Q_DECL_NOTHROW
+bool QtPrivate::isAscii(QLatin1String s) noexcept
 {
     const char *ptr = s.begin();
     const char *end = s.end();
@@ -536,7 +536,7 @@ static bool isAscii(const QChar *&ptr, const QChar *end)
     return true;
 }
 
-bool QtPrivate::isAscii(QStringView s) Q_DECL_NOTHROW
+bool QtPrivate::isAscii(QStringView s) noexcept
 {
     const QChar *ptr = s.begin();
     const QChar *end = s.end();
@@ -544,7 +544,7 @@ bool QtPrivate::isAscii(QStringView s) Q_DECL_NOTHROW
     return isAscii(ptr, end);
 }
 
-bool QtPrivate::isLatin1(QStringView s) Q_DECL_NOTHROW
+bool QtPrivate::isLatin1(QStringView s) noexcept
 {
     const QChar *ptr = s.begin();
     const QChar *end = s.end();
@@ -584,7 +584,7 @@ bool QtPrivate::isLatin1(QStringView s) Q_DECL_NOTHROW
 }
 
 // conversion between Latin 1 and UTF-16
-void qt_from_latin1(ushort *dst, const char *str, size_t size) Q_DECL_NOTHROW
+void qt_from_latin1(ushort *dst, const char *str, size_t size) noexcept
 {
     /* SIMD:
      * Unpacking with SSE has been shown to improve performance on recent CPUs
@@ -1141,7 +1141,7 @@ static int ucstrncmp(const QChar *a, const uchar *c, size_t l)
 }
 
 template <typename Number>
-Q_DECL_CONSTEXPR int lencmp(Number lhs, Number rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR int lencmp(Number lhs, Number rhs) noexcept
 {
     return lhs == rhs ? 0 :
            lhs >  rhs ? 1 :
@@ -1165,7 +1165,7 @@ static int ucstrcmp(const QChar *a, size_t alen, const char *b, size_t blen)
     return cmp ? cmp : lencmp(alen, blen);
 }
 
-static int qt_compare_strings(QStringView lhs, QStringView rhs, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+static int qt_compare_strings(QStringView lhs, QStringView rhs, Qt::CaseSensitivity cs) noexcept
 {
     if (cs == Qt::CaseSensitive)
         return ucstrcmp(lhs.begin(), lhs.size(), rhs.begin(), rhs.size());
@@ -1173,7 +1173,7 @@ static int qt_compare_strings(QStringView lhs, QStringView rhs, Qt::CaseSensitiv
         return ucstricmp(lhs.begin(), lhs.end(), rhs.begin(), rhs.end());
 }
 
-static int qt_compare_strings(QStringView lhs, QLatin1String rhs, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+static int qt_compare_strings(QStringView lhs, QLatin1String rhs, Qt::CaseSensitivity cs) noexcept
 {
     if (cs == Qt::CaseSensitive)
         return ucstrcmp(lhs.begin(), lhs.size(), rhs.begin(), rhs.size());
@@ -1181,12 +1181,12 @@ static int qt_compare_strings(QStringView lhs, QLatin1String rhs, Qt::CaseSensit
         return ucstricmp(lhs.begin(), lhs.end(), rhs.begin(), rhs.end());
 }
 
-static int qt_compare_strings(QLatin1String lhs, QStringView rhs, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+static int qt_compare_strings(QLatin1String lhs, QStringView rhs, Qt::CaseSensitivity cs) noexcept
 {
     return -qt_compare_strings(rhs, lhs, cs);
 }
 
-static int qt_compare_strings(QLatin1String lhs, QLatin1String rhs, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+static int qt_compare_strings(QLatin1String lhs, QLatin1String rhs, Qt::CaseSensitivity cs) noexcept
 {
     if (cs == Qt::CaseInsensitive)
         return qstrnicmp(lhs.data(), lhs.size(), rhs.data(), rhs.size());
@@ -1211,7 +1211,7 @@ static int qt_compare_strings(QLatin1String lhs, QLatin1String rhs, Qt::CaseSens
     of the characters and is very fast, but is not what a human would expect.
     Consider sorting user-visible strings with QString::localeAwareCompare().
 */
-int QtPrivate::compareStrings(QStringView lhs, QStringView rhs, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+int QtPrivate::compareStrings(QStringView lhs, QStringView rhs, Qt::CaseSensitivity cs) noexcept
 {
     return qt_compare_strings(lhs, rhs, cs);
 }
@@ -1231,7 +1231,7 @@ int QtPrivate::compareStrings(QStringView lhs, QStringView rhs, Qt::CaseSensitiv
     of the characters and is very fast, but is not what a human would expect.
     Consider sorting user-visible strings with QString::localeAwareCompare().
 */
-int QtPrivate::compareStrings(QStringView lhs, QLatin1String rhs, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+int QtPrivate::compareStrings(QStringView lhs, QLatin1String rhs, Qt::CaseSensitivity cs) noexcept
 {
     return qt_compare_strings(lhs, rhs, cs);
 }
@@ -1251,7 +1251,7 @@ int QtPrivate::compareStrings(QStringView lhs, QLatin1String rhs, Qt::CaseSensit
     of the characters and is very fast, but is not what a human would expect.
     Consider sorting user-visible strings with QString::localeAwareCompare().
 */
-int QtPrivate::compareStrings(QLatin1String lhs, QStringView rhs, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+int QtPrivate::compareStrings(QLatin1String lhs, QStringView rhs, Qt::CaseSensitivity cs) noexcept
 {
     return qt_compare_strings(lhs, rhs, cs);
 }
@@ -1271,7 +1271,7 @@ int QtPrivate::compareStrings(QLatin1String lhs, QStringView rhs, Qt::CaseSensit
     of the characters and is very fast, but is not what a human would expect.
     Consider sorting user-visible strings with QString::localeAwareCompare().
 */
-int QtPrivate::compareStrings(QLatin1String lhs, QLatin1String rhs, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+int QtPrivate::compareStrings(QLatin1String lhs, QLatin1String rhs, Qt::CaseSensitivity cs) noexcept
 {
     return qt_compare_strings(lhs, rhs, cs);
 }
@@ -2367,7 +2367,7 @@ void QString::expand(int i)
     string.
 */
 
-QString &QString::operator=(const QString &other) Q_DECL_NOTHROW
+QString &QString::operator=(const QString &other) noexcept
 {
     other.d->ref.ref();
     if (!d->ref.deref())
@@ -3353,7 +3353,7 @@ QString &QString::replace(QChar c, QLatin1String after, Qt::CaseSensitivity cs)
   expect. Consider sorting user-interface strings with
   localeAwareCompare().
 */
-bool operator==(const QString &s1, const QString &s2) Q_DECL_NOTHROW
+bool operator==(const QString &s1, const QString &s2) noexcept
 {
     if (s1.d->size != s2.d->size)
         return false;
@@ -3366,7 +3366,7 @@ bool operator==(const QString &s1, const QString &s2) Q_DECL_NOTHROW
     Returns \c true if this string is equal to \a other; otherwise
     returns \c false.
 */
-bool QString::operator==(QLatin1String other) const Q_DECL_NOTHROW
+bool QString::operator==(QLatin1String other) const noexcept
 {
     if (d->size != other.size())
         return false;
@@ -3418,7 +3418,7 @@ bool QString::operator==(QLatin1String other) const Q_DECL_NOTHROW
     expect. Consider sorting user-interface strings using the
     QString::localeAwareCompare() function.
 */
-bool operator<(const QString &s1, const QString &s2) Q_DECL_NOTHROW
+bool operator<(const QString &s1, const QString &s2) noexcept
 {
     return qt_compare_strings(s1, s2, Qt::CaseSensitive) < 0;
 }
@@ -3429,7 +3429,7 @@ bool operator<(const QString &s1, const QString &s2) Q_DECL_NOTHROW
     Returns \c true if this string is lexically less than the parameter
     string called \a other; otherwise returns \c false.
 */
-bool QString::operator<(QLatin1String other) const Q_DECL_NOTHROW
+bool QString::operator<(QLatin1String other) const noexcept
 {
     return qt_compare_strings(*this, other, Qt::CaseSensitive) < 0;
 }
@@ -3538,7 +3538,7 @@ bool QString::operator<(QLatin1String other) const Q_DECL_NOTHROW
     Returns \c true if this string is lexically greater than the parameter
     string \a other; otherwise returns \c false.
 */
-bool QString::operator>(QLatin1String other) const Q_DECL_NOTHROW
+bool QString::operator>(QLatin1String other) const noexcept
 {
     return qt_compare_strings(*this, other, Qt::CaseSensitive) > 0;
 }
@@ -5668,7 +5668,7 @@ QString QString::simplified_helper(QString &str)
 
 namespace {
     template <typename StringView>
-    StringView qt_trimmed(StringView s) Q_DECL_NOTHROW
+    StringView qt_trimmed(StringView s) noexcept
     {
         auto begin = s.begin();
         auto end = s.end();
@@ -5692,12 +5692,12 @@ namespace {
 
     \sa QString::trimmed(), QStringView::trimmed(), QLatin1String::trimmed()
 */
-QStringView QtPrivate::trimmed(QStringView s) Q_DECL_NOTHROW
+QStringView QtPrivate::trimmed(QStringView s) noexcept
 {
     return qt_trimmed(s);
 }
 
-QLatin1String QtPrivate::trimmed(QLatin1String s) Q_DECL_NOTHROW
+QLatin1String QtPrivate::trimmed(QLatin1String s) noexcept
 {
     return qt_trimmed(s);
 }
@@ -6235,7 +6235,7 @@ QString& QString::fill(QChar ch, int size)
 
     Same as compare(*this, \a other, \a cs).
 */
-int QString::compare(const QString &other, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+int QString::compare(const QString &other, Qt::CaseSensitivity cs) const noexcept
 {
     return qt_compare_strings(*this, other, cs);
 }
@@ -6246,7 +6246,7 @@ int QString::compare(const QString &other, Qt::CaseSensitivity cs) const Q_DECL_
     \since 4.5
 */
 int QString::compare_helper(const QChar *data1, int length1, const QChar *data2, int length2,
-                            Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+                            Qt::CaseSensitivity cs) noexcept
 {
     Q_ASSERT(length1 >= 0);
     Q_ASSERT(length2 >= 0);
@@ -6261,7 +6261,7 @@ int QString::compare_helper(const QChar *data1, int length1, const QChar *data2,
 
     Same as compare(*this, \a other, \a cs).
 */
-int QString::compare(QLatin1String other, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+int QString::compare(QLatin1String other, Qt::CaseSensitivity cs) const noexcept
 {
     return qt_compare_strings(*this, other, cs);
 }
@@ -6307,7 +6307,7 @@ int QString::compare_helper(const QChar *data1, int length1, const char *data2,
     \since 4.5
 */
 int QString::compare_helper(const QChar *data1, int length1, QLatin1String s2,
-                            Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+                            Qt::CaseSensitivity cs) noexcept
 {
     Q_ASSERT(length1 >= 0);
     Q_ASSERT(data1 || length1 == 0);
@@ -6801,7 +6801,7 @@ static void append_utf8(QString &qs, const char *cs, int len)
     qs.resize(newEnd - qs.constData());
 }
 
-static uint parse_flag_characters(const char * &c) Q_DECL_NOTHROW
+static uint parse_flag_characters(const char * &c) noexcept
 {
     uint flags = QLocaleData::ZeroPadExponent;
     while (true) {
@@ -6838,7 +6838,7 @@ static int parse_field_width(const char * &c)
 
 enum LengthMod { lm_none, lm_hh, lm_h, lm_l, lm_ll, lm_L, lm_j, lm_z, lm_t };
 
-static inline bool can_consume(const char * &c, char ch) Q_DECL_NOTHROW
+static inline bool can_consume(const char * &c, char ch) noexcept
 {
     if (*c == ch) {
         ++c;
@@ -6847,7 +6847,7 @@ static inline bool can_consume(const char * &c, char ch) Q_DECL_NOTHROW
     return false;
 }
 
-static LengthMod parse_length_modifier(const char * &c) Q_DECL_NOTHROW
+static LengthMod parse_length_modifier(const char * &c) noexcept
 {
     switch (*c++) {
     case 'h': return can_consume(c, 'h') ? lm_hh : lm_h;
@@ -8810,7 +8810,7 @@ namespace {
 struct Part
 {
     Part() : stringRef(), number(0) {}
-    Part(const QString &s, int pos, int len, int num = -1) Q_DECL_NOTHROW
+    Part(const QString &s, int pos, int len, int num = -1) noexcept
         : stringRef(&s, pos, len), number(num) {}
 
     QStringRef stringRef;
@@ -10379,7 +10379,7 @@ QString QStringRef::toString() const {
    Returns \c true if string reference \a s1 is lexically equal to string reference \a s2; otherwise
    returns \c false.
 */
-bool operator==(const QStringRef &s1,const QStringRef &s2) Q_DECL_NOTHROW
+bool operator==(const QStringRef &s1,const QStringRef &s2) noexcept
 {
     return s1.size() == s2.size() && qt_compare_strings(s1, s2, Qt::CaseSensitive) == 0;
 }
@@ -10389,7 +10389,7 @@ bool operator==(const QStringRef &s1,const QStringRef &s2) Q_DECL_NOTHROW
    Returns \c true if string \a s1 is lexically equal to string reference \a s2; otherwise
    returns \c false.
 */
-bool operator==(const QString &s1,const QStringRef &s2) Q_DECL_NOTHROW
+bool operator==(const QString &s1,const QStringRef &s2) noexcept
 {
     return s1.size() == s2.size() && qt_compare_strings(s1, s2, Qt::CaseSensitive) == 0;
 }
@@ -10399,7 +10399,7 @@ bool operator==(const QString &s1,const QStringRef &s2) Q_DECL_NOTHROW
    Returns \c true if string  \a s1 is lexically equal to string reference \a s2; otherwise
    returns \c false.
 */
-bool operator==(QLatin1String s1, const QStringRef &s2) Q_DECL_NOTHROW
+bool operator==(QLatin1String s1, const QStringRef &s2) noexcept
 {
     if (s1.size() != s2.size())
         return false;
@@ -10418,7 +10418,7 @@ bool operator==(QLatin1String s1, const QStringRef &s2) Q_DECL_NOTHROW
     expect. Consider sorting user-interface strings using the
     QString::localeAwareCompare() function.
 */
-bool operator<(const QStringRef &s1,const QStringRef &s2) Q_DECL_NOTHROW
+bool operator<(const QStringRef &s1,const QStringRef &s2) noexcept
 {
     return qt_compare_strings(s1, s2, Qt::CaseSensitive) < 0;
 }
@@ -11553,7 +11553,7 @@ static inline qsizetype qt_string_count(QStringView haystack, QChar ch,
 }
 
 template <typename Haystack, typename Needle>
-bool qt_starts_with_impl(Haystack haystack, Needle needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+bool qt_starts_with_impl(Haystack haystack, Needle needle, Qt::CaseSensitivity cs) noexcept
 {
     if (haystack.isNull())
         return needle.isNull(); // historical behavior, consider changing in ### Qt 6.
@@ -11605,28 +11605,28 @@ static inline bool qt_starts_with(QStringView haystack, QChar needle, Qt::CaseSe
     \sa QtPrivate::endsWith(), QString::endsWith(), QStringView::endsWith(), QLatin1String::endsWith()
 */
 
-bool QtPrivate::startsWith(QStringView haystack, QStringView needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+bool QtPrivate::startsWith(QStringView haystack, QStringView needle, Qt::CaseSensitivity cs) noexcept
 {
     return qt_starts_with_impl(haystack, needle, cs);
 }
 
-bool QtPrivate::startsWith(QStringView haystack, QLatin1String needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+bool QtPrivate::startsWith(QStringView haystack, QLatin1String needle, Qt::CaseSensitivity cs) noexcept
 {
     return qt_starts_with_impl(haystack, needle, cs);
 }
 
-bool QtPrivate::startsWith(QLatin1String haystack, QStringView needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+bool QtPrivate::startsWith(QLatin1String haystack, QStringView needle, Qt::CaseSensitivity cs) noexcept
 {
     return qt_starts_with_impl(haystack, needle, cs);
 }
 
-bool QtPrivate::startsWith(QLatin1String haystack, QLatin1String needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+bool QtPrivate::startsWith(QLatin1String haystack, QLatin1String needle, Qt::CaseSensitivity cs) noexcept
 {
     return qt_starts_with_impl(haystack, needle, cs);
 }
 
 template <typename Haystack, typename Needle>
-bool qt_ends_with_impl(Haystack haystack, Needle needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+bool qt_ends_with_impl(Haystack haystack, Needle needle, Qt::CaseSensitivity cs) noexcept
 {
     if (haystack.isNull())
         return needle.isNull(); // historical behavior, consider changing in ### Qt 6.
@@ -11678,22 +11678,22 @@ static inline bool qt_ends_with(QStringView haystack, QChar needle, Qt::CaseSens
     \sa QtPrivate::startsWith(), QString::endsWith(), QStringView::endsWith(), QLatin1String::endsWith()
 */
 
-bool QtPrivate::endsWith(QStringView haystack, QStringView needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+bool QtPrivate::endsWith(QStringView haystack, QStringView needle, Qt::CaseSensitivity cs) noexcept
 {
     return qt_ends_with_impl(haystack, needle, cs);
 }
 
-bool QtPrivate::endsWith(QStringView haystack, QLatin1String needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+bool QtPrivate::endsWith(QStringView haystack, QLatin1String needle, Qt::CaseSensitivity cs) noexcept
 {
     return qt_ends_with_impl(haystack, needle, cs);
 }
 
-bool QtPrivate::endsWith(QLatin1String haystack, QStringView needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+bool QtPrivate::endsWith(QLatin1String haystack, QStringView needle, Qt::CaseSensitivity cs) noexcept
 {
     return qt_ends_with_impl(haystack, needle, cs);
 }
 
-bool QtPrivate::endsWith(QLatin1String haystack, QLatin1String needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+bool QtPrivate::endsWith(QLatin1String haystack, QLatin1String needle, Qt::CaseSensitivity cs) noexcept
 {
     return qt_ends_with_impl(haystack, needle, cs);
 }
@@ -11707,7 +11707,7 @@ bool QtPrivate::endsWith(QLatin1String haystack, QLatin1String needle, Qt::CaseS
     position \a from. Returns -1 if \a ch could not be found.
 */
 
-qsizetype QtPrivate::findChar(QStringView str, QChar ch, qsizetype from, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+qsizetype QtPrivate::findChar(QStringView str, QChar ch, qsizetype from, Qt::CaseSensitivity cs) noexcept
 {
     if (from < 0)
         from = qMax(from + str.size(), qsizetype(0));
@@ -11731,7 +11731,7 @@ qsizetype QtPrivate::findChar(QStringView str, QChar ch, qsizetype from, Qt::Cas
     return -1;
 }
 
-qsizetype QtPrivate::findString(QStringView haystack0, qsizetype from, QStringView needle0, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+qsizetype QtPrivate::findString(QStringView haystack0, qsizetype from, QStringView needle0, Qt::CaseSensitivity cs) noexcept
 {
     const qsizetype l = haystack0.size();
     const qsizetype sl = needle0.size();
@@ -11806,7 +11806,7 @@ qsizetype QtPrivate::findString(QStringView haystack0, qsizetype from, QStringVi
     return -1;
 }
 
-qsizetype QtPrivate::findString(QStringView haystack, qsizetype from, QLatin1String needle, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+qsizetype QtPrivate::findString(QStringView haystack, qsizetype from, QLatin1String needle, Qt::CaseSensitivity cs) noexcept
 {
     if (haystack.size() < needle.size())
         return -1;
@@ -12271,7 +12271,7 @@ QString QString::toHtmlEscaped() const
 /*!
     \internal
  */
-void QAbstractConcatenable::appendLatin1To(const char *a, int len, QChar *out) Q_DECL_NOTHROW
+void QAbstractConcatenable::appendLatin1To(const char *a, int len, QChar *out) noexcept
 {
     qt_from_latin1(reinterpret_cast<ushort *>(out), a, uint(len));
 }
diff --git a/src/corelib/tools/qstring.h b/src/corelib/tools/qstring.h
index e9a205dfdf..a526a6537a 100644
--- a/src/corelib/tools/qstring.h
+++ b/src/corelib/tools/qstring.h
@@ -91,19 +91,19 @@ template <typename T> class QVector;
 class QLatin1String
 {
 public:
-    Q_DECL_CONSTEXPR inline QLatin1String() Q_DECL_NOTHROW : m_size(0), m_data(nullptr) {}
-    Q_DECL_CONSTEXPR inline explicit QLatin1String(const char *s) Q_DECL_NOTHROW : m_size(s ? int(strlen(s)) : 0), m_data(s) {}
+    Q_DECL_CONSTEXPR inline QLatin1String() noexcept : m_size(0), m_data(nullptr) {}
+    Q_DECL_CONSTEXPR inline explicit QLatin1String(const char *s) noexcept : m_size(s ? int(strlen(s)) : 0), m_data(s) {}
     Q_DECL_CONSTEXPR explicit QLatin1String(const char *f, const char *l)
         : QLatin1String(f, int(l - f)) {}
-    Q_DECL_CONSTEXPR inline explicit QLatin1String(const char *s, int sz) Q_DECL_NOTHROW : m_size(sz), m_data(s) {}
-    inline explicit QLatin1String(const QByteArray &s) Q_DECL_NOTHROW : m_size(int(qstrnlen(s.constData(), s.size()))), m_data(s.constData()) {}
+    Q_DECL_CONSTEXPR inline explicit QLatin1String(const char *s, int sz) noexcept : m_size(sz), m_data(s) {}
+    inline explicit QLatin1String(const QByteArray &s) noexcept : m_size(int(qstrnlen(s.constData(), s.size()))), m_data(s.constData()) {}
 
-    Q_DECL_CONSTEXPR const char *latin1() const Q_DECL_NOTHROW { return m_data; }
-    Q_DECL_CONSTEXPR int size() const Q_DECL_NOTHROW { return m_size; }
-    Q_DECL_CONSTEXPR const char *data() const Q_DECL_NOTHROW { return m_data; }
+    Q_DECL_CONSTEXPR const char *latin1() const noexcept { return m_data; }
+    Q_DECL_CONSTEXPR int size() const noexcept { return m_size; }
+    Q_DECL_CONSTEXPR const char *data() const noexcept { return m_data; }
 
-    Q_DECL_CONSTEXPR bool isNull() const Q_DECL_NOTHROW { return !data(); }
-    Q_DECL_CONSTEXPR bool isEmpty() const Q_DECL_NOTHROW { return !size(); }
+    Q_DECL_CONSTEXPR bool isNull() const noexcept { return !data(); }
+    Q_DECL_CONSTEXPR bool isEmpty() const noexcept { return !size(); }
 
     Q_DECL_CONSTEXPR QLatin1Char at(int i) const
     { return Q_ASSERT(i >= 0), Q_ASSERT(i < size()), QLatin1Char(m_data[i]); }
@@ -112,22 +112,22 @@ public:
     Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QLatin1Char front() const { return at(0); }
     Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QLatin1Char back() const { return at(size() - 1); }
 
-    Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::startsWith(*this, s, cs); }
-    Q_REQUIRED_RESULT bool startsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool startsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::startsWith(*this, s, cs); }
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool startsWith(QChar c) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool startsWith(QChar c) const noexcept
     { return !isEmpty() && front() == c; }
-    Q_REQUIRED_RESULT inline bool startsWith(QChar c, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline bool startsWith(QChar c, Qt::CaseSensitivity cs) const noexcept
     { return QtPrivate::startsWith(*this, QStringView(&c, 1), cs); }
 
-    Q_REQUIRED_RESULT bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::endsWith(*this, s, cs); }
-    Q_REQUIRED_RESULT bool endsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool endsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::endsWith(*this, s, cs); }
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool endsWith(QChar c) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool endsWith(QChar c) const noexcept
     { return !isEmpty() && back() == c; }
-    Q_REQUIRED_RESULT inline bool endsWith(QChar c, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline bool endsWith(QChar c, Qt::CaseSensitivity cs) const noexcept
     { return QtPrivate::endsWith(*this, QStringView(&c, 1), cs); }
 
     using value_type = const char;
@@ -138,18 +138,18 @@ public:
     using difference_type = int; // violates Container concept requirements
     using size_type = int;       // violates Container concept requirements
 
-    Q_DECL_CONSTEXPR const_iterator begin() const Q_DECL_NOTHROW { return data(); }
-    Q_DECL_CONSTEXPR const_iterator cbegin() const Q_DECL_NOTHROW { return data(); }
-    Q_DECL_CONSTEXPR const_iterator end() const Q_DECL_NOTHROW { return data() + size(); }
-    Q_DECL_CONSTEXPR const_iterator cend() const Q_DECL_NOTHROW { return data() + size(); }
+    Q_DECL_CONSTEXPR const_iterator begin() const noexcept { return data(); }
+    Q_DECL_CONSTEXPR const_iterator cbegin() const noexcept { return data(); }
+    Q_DECL_CONSTEXPR const_iterator end() const noexcept { return data() + size(); }
+    Q_DECL_CONSTEXPR const_iterator cend() const noexcept { return data() + size(); }
 
     using reverse_iterator = std::reverse_iterator<iterator>;
     using const_reverse_iterator = reverse_iterator;
 
-    const_reverse_iterator rbegin() const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    const_reverse_iterator crbegin() const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    const_reverse_iterator rend() const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
-    const_reverse_iterator crend() const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
+    const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
+    const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
+    const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
+    const_reverse_iterator crend() const noexcept { return const_reverse_iterator(begin()); }
 
     Q_DECL_CONSTEXPR QLatin1String mid(int pos) const
     { return Q_ASSERT(pos >= 0), Q_ASSERT(pos <= size()), QLatin1String(m_data + pos, m_size - pos); }
@@ -167,14 +167,14 @@ public:
     Q_DECL_RELAXED_CONSTEXPR void truncate(int n)
     { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); m_size = n; }
 
-    Q_REQUIRED_RESULT QLatin1String trimmed() const Q_DECL_NOTHROW { return QtPrivate::trimmed(*this); }
+    Q_REQUIRED_RESULT QLatin1String trimmed() const noexcept { return QtPrivate::trimmed(*this); }
 
-    inline bool operator==(const QString &s) const Q_DECL_NOTHROW;
-    inline bool operator!=(const QString &s) const Q_DECL_NOTHROW;
-    inline bool operator>(const QString &s) const Q_DECL_NOTHROW;
-    inline bool operator<(const QString &s) const Q_DECL_NOTHROW;
-    inline bool operator>=(const QString &s) const Q_DECL_NOTHROW;
-    inline bool operator<=(const QString &s) const Q_DECL_NOTHROW;
+    inline bool operator==(const QString &s) const noexcept;
+    inline bool operator!=(const QString &s) const noexcept;
+    inline bool operator>(const QString &s) const noexcept;
+    inline bool operator<(const QString &s) const noexcept;
+    inline bool operator>=(const QString &s) const noexcept;
+    inline bool operator<=(const QString &s) const noexcept;
 
 #if !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
     inline QT_ASCII_CAST_WARN bool operator==(const char *s) const;
@@ -204,15 +204,15 @@ typedef QLatin1String QLatin1Literal;
 //
 // QLatin1String inline implementations
 //
-inline bool QtPrivate::isLatin1(QLatin1String) Q_DECL_NOTHROW
+inline bool QtPrivate::isLatin1(QLatin1String) noexcept
 { return true; }
 
 //
 // QStringView members that require QLatin1String:
 //
-bool QStringView::startsWith(QLatin1String s, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+bool QStringView::startsWith(QLatin1String s, Qt::CaseSensitivity cs) const noexcept
 { return QtPrivate::startsWith(*this, s, cs); }
-bool QStringView::endsWith(QLatin1String s, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+bool QStringView::endsWith(QLatin1String s, Qt::CaseSensitivity cs) const noexcept
 { return QtPrivate::endsWith(*this, s, cs); }
 
 class Q_CORE_EXPORT QString
@@ -220,22 +220,22 @@ class Q_CORE_EXPORT QString
 public:
     typedef QStringData Data;
 
-    inline QString() Q_DECL_NOTHROW;
+    inline QString() noexcept;
     explicit QString(const QChar *unicode, int size = -1);
     QString(QChar c);
     QString(int size, QChar c);
     inline QString(QLatin1String latin1);
-    inline QString(const QString &) Q_DECL_NOTHROW;
+    inline QString(const QString &) noexcept;
     inline ~QString();
     QString &operator=(QChar c);
-    QString &operator=(const QString &) Q_DECL_NOTHROW;
+    QString &operator=(const QString &) noexcept;
     QString &operator=(QLatin1String latin1);
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QString(QString && other) Q_DECL_NOTHROW : d(other.d) { other.d = Data::sharedNull(); }
-    inline QString &operator=(QString &&other) Q_DECL_NOTHROW
+    inline QString(QString && other) noexcept : d(other.d) { other.d = Data::sharedNull(); }
+    inline QString &operator=(QString &&other) noexcept
     { qSwap(d, other.d); return *this; }
 #endif
-    inline void swap(QString &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    inline void swap(QString &other) noexcept { qSwap(d, other.d); }
     inline int size() const { return d->size; }
     inline int count() const { return d->size; }
     inline int length() const;
@@ -399,7 +399,7 @@ public:
     bool startsWith(const QString &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     bool startsWith(const QStringRef &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
 #endif
-    Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::startsWith(*this, s, cs); }
     bool startsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     bool startsWith(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
@@ -408,7 +408,7 @@ public:
     bool endsWith(const QString &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     bool endsWith(const QStringRef &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
 #endif
-    Q_REQUIRED_RESULT bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::endsWith(*this, s, cs); }
     bool endsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     bool endsWith(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
@@ -613,25 +613,25 @@ public:
     inline QString &setUtf16(const ushort *utf16, int size);
 
 #if QT_STRINGVIEW_LEVEL < 2
-    int compare(const QString &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
-    inline int compare(const QStringRef &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
+    int compare(const QString &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
+    inline int compare(const QStringRef &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
 #endif
-    int compare(QLatin1String other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
-    inline int compare(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
+    int compare(QLatin1String other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
+    inline int compare(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
 
     static inline int compare(const QString &s1, const QString &s2,
-                              Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW
+                              Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept
     { return s1.compare(s2, cs); }
 
     static inline int compare(const QString &s1, QLatin1String s2,
-                              Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW
+                              Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept
     { return s1.compare(s2, cs); }
     static inline int compare(QLatin1String s1, const QString &s2,
-                              Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW
+                              Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept
     { return -s2.compare(s1, cs); }
 
     static int compare(const QString &s1, const QStringRef &s2,
-                       Qt::CaseSensitivity = Qt::CaseSensitive) Q_DECL_NOTHROW;
+                       Qt::CaseSensitivity = Qt::CaseSensitive) noexcept;
 
     int localeAwareCompare(const QString& s) const;
     static int localeAwareCompare(const QString& s1, const QString& s2)
@@ -671,19 +671,19 @@ public:
     static QString number(qulonglong, int base=10);
     static QString number(double, char f='g', int prec=6);
 
-    friend Q_CORE_EXPORT bool operator==(const QString &s1, const QString &s2) Q_DECL_NOTHROW;
-    friend Q_CORE_EXPORT bool operator<(const QString &s1, const QString &s2) Q_DECL_NOTHROW;
-    friend inline bool operator>(const QString &s1, const QString &s2) Q_DECL_NOTHROW { return s2 < s1; }
-    friend inline bool operator!=(const QString &s1, const QString &s2) Q_DECL_NOTHROW { return !(s1 == s2); }
-    friend inline bool operator<=(const QString &s1, const QString &s2) Q_DECL_NOTHROW { return !(s1 > s2); }
-    friend inline bool operator>=(const QString &s1, const QString &s2) Q_DECL_NOTHROW { return !(s1 < s2); }
+    friend Q_CORE_EXPORT bool operator==(const QString &s1, const QString &s2) noexcept;
+    friend Q_CORE_EXPORT bool operator<(const QString &s1, const QString &s2) noexcept;
+    friend inline bool operator>(const QString &s1, const QString &s2) noexcept { return s2 < s1; }
+    friend inline bool operator!=(const QString &s1, const QString &s2) noexcept { return !(s1 == s2); }
+    friend inline bool operator<=(const QString &s1, const QString &s2) noexcept { return !(s1 > s2); }
+    friend inline bool operator>=(const QString &s1, const QString &s2) noexcept { return !(s1 < s2); }
 
-    bool operator==(QLatin1String s) const Q_DECL_NOTHROW;
-    bool operator<(QLatin1String s) const Q_DECL_NOTHROW;
-    bool operator>(QLatin1String s) const Q_DECL_NOTHROW;
-    inline bool operator!=(QLatin1String s) const Q_DECL_NOTHROW { return !operator==(s); }
-    inline bool operator<=(QLatin1String s) const Q_DECL_NOTHROW { return !operator>(s); }
-    inline bool operator>=(QLatin1String s) const Q_DECL_NOTHROW { return !operator<(s); }
+    bool operator==(QLatin1String s) const noexcept;
+    bool operator<(QLatin1String s) const noexcept;
+    bool operator>(QLatin1String s) const noexcept;
+    inline bool operator!=(QLatin1String s) const noexcept { return !operator==(s); }
+    inline bool operator<=(QLatin1String s) const noexcept { return !operator>(s); }
+    inline bool operator>=(QLatin1String s) const noexcept { return !operator<(s); }
 
     // ASCII compatibility
 #if defined(QT_RESTRICTED_CAST_FROM_ASCII)
@@ -844,15 +844,15 @@ private:
 
     Data *d;
 
-    friend inline bool operator==(QChar, const QString &) Q_DECL_NOTHROW;
-    friend inline bool operator< (QChar, const QString &) Q_DECL_NOTHROW;
-    friend inline bool operator> (QChar, const QString &) Q_DECL_NOTHROW;
-    friend inline bool operator==(QChar, const QStringRef &) Q_DECL_NOTHROW;
-    friend inline bool operator< (QChar, const QStringRef &) Q_DECL_NOTHROW;
-    friend inline bool operator> (QChar, const QStringRef &) Q_DECL_NOTHROW;
-    friend inline bool operator==(QChar, QLatin1String) Q_DECL_NOTHROW;
-    friend inline bool operator< (QChar, QLatin1String) Q_DECL_NOTHROW;
-    friend inline bool operator> (QChar, QLatin1String) Q_DECL_NOTHROW;
+    friend inline bool operator==(QChar, const QString &) noexcept;
+    friend inline bool operator< (QChar, const QString &) noexcept;
+    friend inline bool operator> (QChar, const QString &) noexcept;
+    friend inline bool operator==(QChar, const QStringRef &) noexcept;
+    friend inline bool operator< (QChar, const QStringRef &) noexcept;
+    friend inline bool operator> (QChar, const QStringRef &) noexcept;
+    friend inline bool operator==(QChar, QLatin1String) noexcept;
+    friend inline bool operator< (QChar, QLatin1String) noexcept;
+    friend inline bool operator> (QChar, QLatin1String) noexcept;
 
     void reallocData(uint alloc, bool grow = false);
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
@@ -861,13 +861,13 @@ private:
     QString multiArg(int numArgs, const QString **args) const;
     static int compare_helper(const QChar *data1, int length1,
                               const QChar *data2, int length2,
-                              Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
+                              Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
     static int compare_helper(const QChar *data1, int length1,
                               const char *data2, int length2,
                               Qt::CaseSensitivity cs = Qt::CaseSensitive);
     static int compare_helper(const QChar *data1, int length1,
                               QLatin1String s2,
-                              Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
+                              Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
     static int localeAwareCompare_helper(const QChar *data1, int length1,
                                          const QChar *data2, int length2);
     static QString toLower_helper(const QString &str);
@@ -956,7 +956,7 @@ inline bool QString::isDetached() const
 { return !d->ref.isShared(); }
 inline void QString::clear()
 { if (!isNull()) *this = QString(); }
-inline QString::QString(const QString &other) Q_DECL_NOTHROW : d(other.d)
+inline QString::QString(const QString &other) noexcept : d(other.d)
 { Q_ASSERT(&other != this); d->ref.ref(); }
 inline int QString::capacity() const
 { return d->alloc ? d->alloc - 1 : 0; }
@@ -1128,7 +1128,7 @@ inline void QCharRef::setRow(uchar arow) { QChar(*this).setRow(arow); }
 inline void QCharRef::setCell(uchar acell) { QChar(*this).setCell(acell); }
 
 
-inline QString::QString() Q_DECL_NOTHROW : d(Data::sharedNull()) {}
+inline QString::QString() noexcept : d(Data::sharedNull()) {}
 inline QString::~QString() { if (!d->ref.deref()) Data::deallocate(d); }
 
 inline void QString::reserve(int asize)
@@ -1200,34 +1200,34 @@ QT_DEPRECATED_X("use !QString::isNull()")
 inline bool operator!=(const QString &s, QString::Null) { return !s.isNull(); }
 #endif
 
-inline bool operator==(QLatin1String s1, QLatin1String s2) Q_DECL_NOTHROW
+inline bool operator==(QLatin1String s1, QLatin1String s2) noexcept
 { return s1.size() == s2.size() && (!s1.size() || !memcmp(s1.latin1(), s2.latin1(), s1.size())); }
-inline bool operator!=(QLatin1String s1, QLatin1String s2) Q_DECL_NOTHROW
+inline bool operator!=(QLatin1String s1, QLatin1String s2) noexcept
 { return !operator==(s1, s2); }
-inline bool operator<(QLatin1String s1, QLatin1String s2) Q_DECL_NOTHROW
+inline bool operator<(QLatin1String s1, QLatin1String s2) noexcept
 {
     const int len = qMin(s1.size(), s2.size());
     const int r = len ? memcmp(s1.latin1(), s2.latin1(), len) : 0;
     return r < 0 || (r == 0 && s1.size() < s2.size());
 }
-inline bool operator>(QLatin1String s1, QLatin1String s2) Q_DECL_NOTHROW
+inline bool operator>(QLatin1String s1, QLatin1String s2) noexcept
 { return operator<(s2, s1); }
-inline bool operator<=(QLatin1String s1, QLatin1String s2) Q_DECL_NOTHROW
+inline bool operator<=(QLatin1String s1, QLatin1String s2) noexcept
 { return !operator>(s1, s2); }
-inline bool operator>=(QLatin1String s1, QLatin1String s2) Q_DECL_NOTHROW
+inline bool operator>=(QLatin1String s1, QLatin1String s2) noexcept
 { return !operator<(s1, s2); }
 
-inline bool QLatin1String::operator==(const QString &s) const Q_DECL_NOTHROW
+inline bool QLatin1String::operator==(const QString &s) const noexcept
 { return s == *this; }
-inline bool QLatin1String::operator!=(const QString &s) const Q_DECL_NOTHROW
+inline bool QLatin1String::operator!=(const QString &s) const noexcept
 { return s != *this; }
-inline bool QLatin1String::operator>(const QString &s) const Q_DECL_NOTHROW
+inline bool QLatin1String::operator>(const QString &s) const noexcept
 { return s < *this; }
-inline bool QLatin1String::operator<(const QString &s) const Q_DECL_NOTHROW
+inline bool QLatin1String::operator<(const QString &s) const noexcept
 { return s > *this; }
-inline bool QLatin1String::operator>=(const QString &s) const Q_DECL_NOTHROW
+inline bool QLatin1String::operator>=(const QString &s) const noexcept
 { return s <= *this; }
-inline bool QLatin1String::operator<=(const QString &s) const Q_DECL_NOTHROW
+inline bool QLatin1String::operator<=(const QString &s) const noexcept
 { return s >= *this; }
 
 #if !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
@@ -1434,14 +1434,14 @@ public:
 
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
     // ### Qt 6: remove all of these, the implicit ones are fine
-    QStringRef(const QStringRef &other) Q_DECL_NOTHROW
+    QStringRef(const QStringRef &other) noexcept
         :m_string(other.m_string), m_position(other.m_position), m_size(other.m_size)
         {}
 #ifdef Q_COMPILER_RVALUE_REFS
-    QStringRef(QStringRef &&other) Q_DECL_NOTHROW : m_string(other.m_string), m_position(other.m_position), m_size(other.m_size) {}
-    QStringRef &operator=(QStringRef &&other) Q_DECL_NOTHROW { return *this = other; }
+    QStringRef(QStringRef &&other) noexcept : m_string(other.m_string), m_position(other.m_position), m_size(other.m_size) {}
+    QStringRef &operator=(QStringRef &&other) noexcept { return *this = other; }
 #endif
-    QStringRef &operator=(const QStringRef &other) Q_DECL_NOTHROW
+    QStringRef &operator=(const QStringRef &other) noexcept
     {
         m_string = other.m_string; m_position = other.m_position;
         m_size = other.m_size; return *this;
@@ -1484,8 +1484,8 @@ public:
     Q_REQUIRED_RESULT QStringRef chopped(int n) const
     { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); return left(size() - n); }
 
-    void truncate(int pos) Q_DECL_NOTHROW { m_size = qBound(0, pos, m_size); }
-    void chop(int n) Q_DECL_NOTHROW
+    void truncate(int pos) noexcept { m_size = qBound(0, pos, m_size); }
+    void chop(int n) noexcept
     {
         if (n >= m_size)
             m_size = 0;
@@ -1495,7 +1495,7 @@ public:
 
     bool isRightToLeft() const;
 
-    Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::startsWith(*this, s, cs); }
     bool startsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     bool startsWith(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
@@ -1504,7 +1504,7 @@ public:
     bool startsWith(const QStringRef &c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
 #endif
 
-    Q_REQUIRED_RESULT bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::endsWith(*this, s, cs); }
     bool endsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     bool endsWith(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
@@ -1567,19 +1567,19 @@ public:
     inline QT_ASCII_CAST_WARN bool operator>=(const char *s) const;
 #endif
 
-    int compare(const QString &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
-    int compare(const QStringRef &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
-    int compare(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
+    int compare(const QString &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
+    int compare(const QStringRef &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
+    int compare(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
 #if !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
     int compare(const QByteArray &s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
     { return QString::compare_helper(unicode(), size(), s.data(), qstrnlen(s.data(), s.size()), cs); }
 #endif
     static int compare(const QStringRef &s1, const QString &s2,
-                       Qt::CaseSensitivity = Qt::CaseSensitive) Q_DECL_NOTHROW;
+                       Qt::CaseSensitivity = Qt::CaseSensitive) noexcept;
     static int compare(const QStringRef &s1, const QStringRef &s2,
-                       Qt::CaseSensitivity = Qt::CaseSensitive) Q_DECL_NOTHROW;
+                       Qt::CaseSensitivity = Qt::CaseSensitive) noexcept;
     static int compare(const QStringRef &s1, QLatin1String s2,
-                       Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
+                       Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 
     int localeAwareCompare(const QString &s) const;
     int localeAwareCompare(const QStringRef &s) const;
@@ -1610,162 +1610,162 @@ inline QStringRef::QStringRef(const QString *aString)
     :m_string(aString), m_position(0), m_size(aString?aString->size() : 0){}
 
 // QStringRef <> QStringRef
-Q_CORE_EXPORT bool operator==(const QStringRef &s1, const QStringRef &s2) Q_DECL_NOTHROW;
-inline bool operator!=(const QStringRef &s1, const QStringRef &s2) Q_DECL_NOTHROW
+Q_CORE_EXPORT bool operator==(const QStringRef &s1, const QStringRef &s2) noexcept;
+inline bool operator!=(const QStringRef &s1, const QStringRef &s2) noexcept
 { return !(s1 == s2); }
-Q_CORE_EXPORT bool operator<(const QStringRef &s1, const QStringRef &s2) Q_DECL_NOTHROW;
-inline bool operator>(const QStringRef &s1, const QStringRef &s2) Q_DECL_NOTHROW
+Q_CORE_EXPORT bool operator<(const QStringRef &s1, const QStringRef &s2) noexcept;
+inline bool operator>(const QStringRef &s1, const QStringRef &s2) noexcept
 { return s2 < s1; }
-inline bool operator<=(const QStringRef &s1, const QStringRef &s2) Q_DECL_NOTHROW
+inline bool operator<=(const QStringRef &s1, const QStringRef &s2) noexcept
 { return !(s1 > s2); }
-inline bool operator>=(const QStringRef &s1, const QStringRef &s2) Q_DECL_NOTHROW
+inline bool operator>=(const QStringRef &s1, const QStringRef &s2) noexcept
 { return !(s1 < s2); }
 
 // QString <> QStringRef
-Q_CORE_EXPORT bool operator==(const QString &lhs, const QStringRef &rhs) Q_DECL_NOTHROW;
-inline bool operator!=(const QString &lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return lhs.compare(rhs) != 0; }
-inline bool operator< (const QString &lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return lhs.compare(rhs) <  0; }
-inline bool operator> (const QString &lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return lhs.compare(rhs) >  0; }
-inline bool operator<=(const QString &lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return lhs.compare(rhs) <= 0; }
-inline bool operator>=(const QString &lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return lhs.compare(rhs) >= 0; }
-
-inline bool operator==(const QStringRef &lhs, const QString &rhs) Q_DECL_NOTHROW { return rhs == lhs; }
-inline bool operator!=(const QStringRef &lhs, const QString &rhs) Q_DECL_NOTHROW { return rhs != lhs; }
-inline bool operator< (const QStringRef &lhs, const QString &rhs) Q_DECL_NOTHROW { return rhs >  lhs; }
-inline bool operator> (const QStringRef &lhs, const QString &rhs) Q_DECL_NOTHROW { return rhs <  lhs; }
-inline bool operator<=(const QStringRef &lhs, const QString &rhs) Q_DECL_NOTHROW { return rhs >= lhs; }
-inline bool operator>=(const QStringRef &lhs, const QString &rhs) Q_DECL_NOTHROW { return rhs <= lhs; }
+Q_CORE_EXPORT bool operator==(const QString &lhs, const QStringRef &rhs) noexcept;
+inline bool operator!=(const QString &lhs, const QStringRef &rhs) noexcept { return lhs.compare(rhs) != 0; }
+inline bool operator< (const QString &lhs, const QStringRef &rhs) noexcept { return lhs.compare(rhs) <  0; }
+inline bool operator> (const QString &lhs, const QStringRef &rhs) noexcept { return lhs.compare(rhs) >  0; }
+inline bool operator<=(const QString &lhs, const QStringRef &rhs) noexcept { return lhs.compare(rhs) <= 0; }
+inline bool operator>=(const QString &lhs, const QStringRef &rhs) noexcept { return lhs.compare(rhs) >= 0; }
+
+inline bool operator==(const QStringRef &lhs, const QString &rhs) noexcept { return rhs == lhs; }
+inline bool operator!=(const QStringRef &lhs, const QString &rhs) noexcept { return rhs != lhs; }
+inline bool operator< (const QStringRef &lhs, const QString &rhs) noexcept { return rhs >  lhs; }
+inline bool operator> (const QStringRef &lhs, const QString &rhs) noexcept { return rhs <  lhs; }
+inline bool operator<=(const QStringRef &lhs, const QString &rhs) noexcept { return rhs >= lhs; }
+inline bool operator>=(const QStringRef &lhs, const QString &rhs) noexcept { return rhs <= lhs; }
 
 #if QT_STRINGVIEW_LEVEL < 2
-inline int QString::compare(const QStringRef &s, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+inline int QString::compare(const QStringRef &s, Qt::CaseSensitivity cs) const noexcept
 { return QString::compare_helper(constData(), length(), s.constData(), s.length(), cs); }
 #endif
-inline int QString::compare(QStringView s, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+inline int QString::compare(QStringView s, Qt::CaseSensitivity cs) const noexcept
 { return -s.compare(*this, cs); }
-inline int QString::compare(const QString &s1, const QStringRef &s2, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+inline int QString::compare(const QString &s1, const QStringRef &s2, Qt::CaseSensitivity cs) noexcept
 { return QString::compare_helper(s1.constData(), s1.length(), s2.constData(), s2.length(), cs); }
-inline int QStringRef::compare(const QString &s, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+inline int QStringRef::compare(const QString &s, Qt::CaseSensitivity cs) const noexcept
 { return QString::compare_helper(constData(), length(), s.constData(), s.length(), cs); }
-inline int QStringRef::compare(const QStringRef &s, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+inline int QStringRef::compare(const QStringRef &s, Qt::CaseSensitivity cs) const noexcept
 { return QString::compare_helper(constData(), length(), s.constData(), s.length(), cs); }
-inline int QStringRef::compare(QLatin1String s, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+inline int QStringRef::compare(QLatin1String s, Qt::CaseSensitivity cs) const noexcept
 { return QString::compare_helper(constData(), length(), s, cs); }
-inline int QStringRef::compare(const QStringRef &s1, const QString &s2, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+inline int QStringRef::compare(const QStringRef &s1, const QString &s2, Qt::CaseSensitivity cs) noexcept
 { return QString::compare_helper(s1.constData(), s1.length(), s2.constData(), s2.length(), cs); }
-inline int QStringRef::compare(const QStringRef &s1, const QStringRef &s2, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+inline int QStringRef::compare(const QStringRef &s1, const QStringRef &s2, Qt::CaseSensitivity cs) noexcept
 { return QString::compare_helper(s1.constData(), s1.length(), s2.constData(), s2.length(), cs); }
-inline int QStringRef::compare(const QStringRef &s1, QLatin1String s2, Qt::CaseSensitivity cs) Q_DECL_NOTHROW
+inline int QStringRef::compare(const QStringRef &s1, QLatin1String s2, Qt::CaseSensitivity cs) noexcept
 { return QString::compare_helper(s1.constData(), s1.length(), s2, cs); }
 
 // QLatin1String <> QStringRef
-Q_CORE_EXPORT bool operator==(QLatin1String lhs, const QStringRef &rhs) Q_DECL_NOTHROW;
-inline bool operator!=(QLatin1String lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return rhs.compare(lhs) != 0; }
-inline bool operator< (QLatin1String lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return rhs.compare(lhs) >  0; }
-inline bool operator> (QLatin1String lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return rhs.compare(lhs) <  0; }
-inline bool operator<=(QLatin1String lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return rhs.compare(lhs) >= 0; }
-inline bool operator>=(QLatin1String lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return rhs.compare(lhs) <= 0; }
-
-inline bool operator==(const QStringRef &lhs, QLatin1String rhs) Q_DECL_NOTHROW { return rhs == lhs; }
-inline bool operator!=(const QStringRef &lhs, QLatin1String rhs) Q_DECL_NOTHROW { return rhs != lhs; }
-inline bool operator< (const QStringRef &lhs, QLatin1String rhs) Q_DECL_NOTHROW { return rhs >  lhs; }
-inline bool operator> (const QStringRef &lhs, QLatin1String rhs) Q_DECL_NOTHROW { return rhs <  lhs; }
-inline bool operator<=(const QStringRef &lhs, QLatin1String rhs) Q_DECL_NOTHROW { return rhs >= lhs; }
-inline bool operator>=(const QStringRef &lhs, QLatin1String rhs) Q_DECL_NOTHROW { return rhs <= lhs; }
+Q_CORE_EXPORT bool operator==(QLatin1String lhs, const QStringRef &rhs) noexcept;
+inline bool operator!=(QLatin1String lhs, const QStringRef &rhs) noexcept { return rhs.compare(lhs) != 0; }
+inline bool operator< (QLatin1String lhs, const QStringRef &rhs) noexcept { return rhs.compare(lhs) >  0; }
+inline bool operator> (QLatin1String lhs, const QStringRef &rhs) noexcept { return rhs.compare(lhs) <  0; }
+inline bool operator<=(QLatin1String lhs, const QStringRef &rhs) noexcept { return rhs.compare(lhs) >= 0; }
+inline bool operator>=(QLatin1String lhs, const QStringRef &rhs) noexcept { return rhs.compare(lhs) <= 0; }
+
+inline bool operator==(const QStringRef &lhs, QLatin1String rhs) noexcept { return rhs == lhs; }
+inline bool operator!=(const QStringRef &lhs, QLatin1String rhs) noexcept { return rhs != lhs; }
+inline bool operator< (const QStringRef &lhs, QLatin1String rhs) noexcept { return rhs >  lhs; }
+inline bool operator> (const QStringRef &lhs, QLatin1String rhs) noexcept { return rhs <  lhs; }
+inline bool operator<=(const QStringRef &lhs, QLatin1String rhs) noexcept { return rhs >= lhs; }
+inline bool operator>=(const QStringRef &lhs, QLatin1String rhs) noexcept { return rhs <= lhs; }
 
 // QChar <> QString
-inline bool operator==(QChar lhs, const QString &rhs) Q_DECL_NOTHROW
+inline bool operator==(QChar lhs, const QString &rhs) noexcept
 { return rhs.size() == 1 && lhs == rhs.front(); }
-inline bool operator< (QChar lhs, const QString &rhs) Q_DECL_NOTHROW
+inline bool operator< (QChar lhs, const QString &rhs) noexcept
 { return QString::compare_helper(&lhs, 1, rhs.data(), rhs.size()) <  0; }
-inline bool operator> (QChar lhs, const QString &rhs) Q_DECL_NOTHROW
+inline bool operator> (QChar lhs, const QString &rhs) noexcept
 { return QString::compare_helper(&lhs, 1, rhs.data(), rhs.size()) >  0; }
 
-inline bool operator!=(QChar lhs, const QString &rhs) Q_DECL_NOTHROW { return !(lhs == rhs); }
-inline bool operator<=(QChar lhs, const QString &rhs) Q_DECL_NOTHROW { return !(lhs >  rhs); }
-inline bool operator>=(QChar lhs, const QString &rhs) Q_DECL_NOTHROW { return !(lhs <  rhs); }
+inline bool operator!=(QChar lhs, const QString &rhs) noexcept { return !(lhs == rhs); }
+inline bool operator<=(QChar lhs, const QString &rhs) noexcept { return !(lhs >  rhs); }
+inline bool operator>=(QChar lhs, const QString &rhs) noexcept { return !(lhs <  rhs); }
 
-inline bool operator==(const QString &lhs, QChar rhs) Q_DECL_NOTHROW { return   rhs == lhs; }
-inline bool operator!=(const QString &lhs, QChar rhs) Q_DECL_NOTHROW { return !(rhs == lhs); }
-inline bool operator< (const QString &lhs, QChar rhs) Q_DECL_NOTHROW { return   rhs >  lhs; }
-inline bool operator> (const QString &lhs, QChar rhs) Q_DECL_NOTHROW { return   rhs <  lhs; }
-inline bool operator<=(const QString &lhs, QChar rhs) Q_DECL_NOTHROW { return !(rhs <  lhs); }
-inline bool operator>=(const QString &lhs, QChar rhs) Q_DECL_NOTHROW { return !(rhs >  lhs); }
+inline bool operator==(const QString &lhs, QChar rhs) noexcept { return   rhs == lhs; }
+inline bool operator!=(const QString &lhs, QChar rhs) noexcept { return !(rhs == lhs); }
+inline bool operator< (const QString &lhs, QChar rhs) noexcept { return   rhs >  lhs; }
+inline bool operator> (const QString &lhs, QChar rhs) noexcept { return   rhs <  lhs; }
+inline bool operator<=(const QString &lhs, QChar rhs) noexcept { return !(rhs <  lhs); }
+inline bool operator>=(const QString &lhs, QChar rhs) noexcept { return !(rhs >  lhs); }
 
 // QChar <> QStringRef
-inline bool operator==(QChar lhs, const QStringRef &rhs) Q_DECL_NOTHROW
+inline bool operator==(QChar lhs, const QStringRef &rhs) noexcept
 { return rhs.size() == 1 && lhs == rhs.front(); }
-inline bool operator< (QChar lhs, const QStringRef &rhs) Q_DECL_NOTHROW
+inline bool operator< (QChar lhs, const QStringRef &rhs) noexcept
 { return QString::compare_helper(&lhs, 1, rhs.data(), rhs.size()) <  0; }
-inline bool operator> (QChar lhs, const QStringRef &rhs) Q_DECL_NOTHROW
+inline bool operator> (QChar lhs, const QStringRef &rhs) noexcept
 { return QString::compare_helper(&lhs, 1, rhs.data(), rhs.size()) >  0; }
 
-inline bool operator!=(QChar lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return !(lhs == rhs); }
-inline bool operator<=(QChar lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return !(lhs >  rhs); }
-inline bool operator>=(QChar lhs, const QStringRef &rhs) Q_DECL_NOTHROW { return !(lhs <  rhs); }
+inline bool operator!=(QChar lhs, const QStringRef &rhs) noexcept { return !(lhs == rhs); }
+inline bool operator<=(QChar lhs, const QStringRef &rhs) noexcept { return !(lhs >  rhs); }
+inline bool operator>=(QChar lhs, const QStringRef &rhs) noexcept { return !(lhs <  rhs); }
 
-inline bool operator==(const QStringRef &lhs, QChar rhs) Q_DECL_NOTHROW { return   rhs == lhs; }
-inline bool operator!=(const QStringRef &lhs, QChar rhs) Q_DECL_NOTHROW { return !(rhs == lhs); }
-inline bool operator< (const QStringRef &lhs, QChar rhs) Q_DECL_NOTHROW { return   rhs >  lhs; }
-inline bool operator> (const QStringRef &lhs, QChar rhs) Q_DECL_NOTHROW { return   rhs <  lhs; }
-inline bool operator<=(const QStringRef &lhs, QChar rhs) Q_DECL_NOTHROW { return !(rhs <  lhs); }
-inline bool operator>=(const QStringRef &lhs, QChar rhs) Q_DECL_NOTHROW { return !(rhs >  lhs); }
+inline bool operator==(const QStringRef &lhs, QChar rhs) noexcept { return   rhs == lhs; }
+inline bool operator!=(const QStringRef &lhs, QChar rhs) noexcept { return !(rhs == lhs); }
+inline bool operator< (const QStringRef &lhs, QChar rhs) noexcept { return   rhs >  lhs; }
+inline bool operator> (const QStringRef &lhs, QChar rhs) noexcept { return   rhs <  lhs; }
+inline bool operator<=(const QStringRef &lhs, QChar rhs) noexcept { return !(rhs <  lhs); }
+inline bool operator>=(const QStringRef &lhs, QChar rhs) noexcept { return !(rhs >  lhs); }
 
 // QChar <> QLatin1String
-inline bool operator==(QChar lhs, QLatin1String rhs) Q_DECL_NOTHROW
+inline bool operator==(QChar lhs, QLatin1String rhs) noexcept
 { return rhs.size() == 1 && lhs == rhs.front(); }
-inline bool operator< (QChar lhs, QLatin1String rhs) Q_DECL_NOTHROW
+inline bool operator< (QChar lhs, QLatin1String rhs) noexcept
 { return QString::compare_helper(&lhs, 1, rhs) <  0; }
-inline bool operator> (QChar lhs, QLatin1String rhs) Q_DECL_NOTHROW
+inline bool operator> (QChar lhs, QLatin1String rhs) noexcept
 { return QString::compare_helper(&lhs, 1, rhs) >  0; }
 
-inline bool operator!=(QChar lhs, QLatin1String rhs) Q_DECL_NOTHROW { return !(lhs == rhs); }
-inline bool operator<=(QChar lhs, QLatin1String rhs) Q_DECL_NOTHROW { return !(lhs >  rhs); }
-inline bool operator>=(QChar lhs, QLatin1String rhs) Q_DECL_NOTHROW { return !(lhs <  rhs); }
+inline bool operator!=(QChar lhs, QLatin1String rhs) noexcept { return !(lhs == rhs); }
+inline bool operator<=(QChar lhs, QLatin1String rhs) noexcept { return !(lhs >  rhs); }
+inline bool operator>=(QChar lhs, QLatin1String rhs) noexcept { return !(lhs <  rhs); }
 
-inline bool operator==(QLatin1String lhs, QChar rhs) Q_DECL_NOTHROW { return   rhs == lhs; }
-inline bool operator!=(QLatin1String lhs, QChar rhs) Q_DECL_NOTHROW { return !(rhs == lhs); }
-inline bool operator< (QLatin1String lhs, QChar rhs) Q_DECL_NOTHROW { return   rhs >  lhs; }
-inline bool operator> (QLatin1String lhs, QChar rhs) Q_DECL_NOTHROW { return   rhs <  lhs; }
-inline bool operator<=(QLatin1String lhs, QChar rhs) Q_DECL_NOTHROW { return !(rhs <  lhs); }
-inline bool operator>=(QLatin1String lhs, QChar rhs) Q_DECL_NOTHROW { return !(rhs >  lhs); }
+inline bool operator==(QLatin1String lhs, QChar rhs) noexcept { return   rhs == lhs; }
+inline bool operator!=(QLatin1String lhs, QChar rhs) noexcept { return !(rhs == lhs); }
+inline bool operator< (QLatin1String lhs, QChar rhs) noexcept { return   rhs >  lhs; }
+inline bool operator> (QLatin1String lhs, QChar rhs) noexcept { return   rhs <  lhs; }
+inline bool operator<=(QLatin1String lhs, QChar rhs) noexcept { return !(rhs <  lhs); }
+inline bool operator>=(QLatin1String lhs, QChar rhs) noexcept { return !(rhs >  lhs); }
 
 // QStringView <> QStringView
-inline bool operator==(QStringView lhs, QStringView rhs) Q_DECL_NOTHROW { return lhs.size() == rhs.size() && QtPrivate::compareStrings(lhs, rhs) == 0; }
-inline bool operator!=(QStringView lhs, QStringView rhs) Q_DECL_NOTHROW { return !(lhs == rhs); }
-inline bool operator< (QStringView lhs, QStringView rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) <  0; }
-inline bool operator<=(QStringView lhs, QStringView rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) <= 0; }
-inline bool operator> (QStringView lhs, QStringView rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) >  0; }
-inline bool operator>=(QStringView lhs, QStringView rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) >= 0; }
+inline bool operator==(QStringView lhs, QStringView rhs) noexcept { return lhs.size() == rhs.size() && QtPrivate::compareStrings(lhs, rhs) == 0; }
+inline bool operator!=(QStringView lhs, QStringView rhs) noexcept { return !(lhs == rhs); }
+inline bool operator< (QStringView lhs, QStringView rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) <  0; }
+inline bool operator<=(QStringView lhs, QStringView rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) <= 0; }
+inline bool operator> (QStringView lhs, QStringView rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) >  0; }
+inline bool operator>=(QStringView lhs, QStringView rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) >= 0; }
 
 // QStringView <> QChar
-inline bool operator==(QStringView lhs, QChar rhs) Q_DECL_NOTHROW { return lhs == QStringView(&rhs, 1); }
-inline bool operator!=(QStringView lhs, QChar rhs) Q_DECL_NOTHROW { return lhs != QStringView(&rhs, 1); }
-inline bool operator< (QStringView lhs, QChar rhs) Q_DECL_NOTHROW { return lhs <  QStringView(&rhs, 1); }
-inline bool operator<=(QStringView lhs, QChar rhs) Q_DECL_NOTHROW { return lhs <= QStringView(&rhs, 1); }
-inline bool operator> (QStringView lhs, QChar rhs) Q_DECL_NOTHROW { return lhs >  QStringView(&rhs, 1); }
-inline bool operator>=(QStringView lhs, QChar rhs) Q_DECL_NOTHROW { return lhs >= QStringView(&rhs, 1); }
-
-inline bool operator==(QChar lhs, QStringView rhs) Q_DECL_NOTHROW { return QStringView(&lhs, 1) == rhs; }
-inline bool operator!=(QChar lhs, QStringView rhs) Q_DECL_NOTHROW { return QStringView(&lhs, 1) != rhs; }
-inline bool operator< (QChar lhs, QStringView rhs) Q_DECL_NOTHROW { return QStringView(&lhs, 1) <  rhs; }
-inline bool operator<=(QChar lhs, QStringView rhs) Q_DECL_NOTHROW { return QStringView(&lhs, 1) <= rhs; }
-inline bool operator> (QChar lhs, QStringView rhs) Q_DECL_NOTHROW { return QStringView(&lhs, 1) >  rhs; }
-inline bool operator>=(QChar lhs, QStringView rhs) Q_DECL_NOTHROW { return QStringView(&lhs, 1) >= rhs; }
+inline bool operator==(QStringView lhs, QChar rhs) noexcept { return lhs == QStringView(&rhs, 1); }
+inline bool operator!=(QStringView lhs, QChar rhs) noexcept { return lhs != QStringView(&rhs, 1); }
+inline bool operator< (QStringView lhs, QChar rhs) noexcept { return lhs <  QStringView(&rhs, 1); }
+inline bool operator<=(QStringView lhs, QChar rhs) noexcept { return lhs <= QStringView(&rhs, 1); }
+inline bool operator> (QStringView lhs, QChar rhs) noexcept { return lhs >  QStringView(&rhs, 1); }
+inline bool operator>=(QStringView lhs, QChar rhs) noexcept { return lhs >= QStringView(&rhs, 1); }
+
+inline bool operator==(QChar lhs, QStringView rhs) noexcept { return QStringView(&lhs, 1) == rhs; }
+inline bool operator!=(QChar lhs, QStringView rhs) noexcept { return QStringView(&lhs, 1) != rhs; }
+inline bool operator< (QChar lhs, QStringView rhs) noexcept { return QStringView(&lhs, 1) <  rhs; }
+inline bool operator<=(QChar lhs, QStringView rhs) noexcept { return QStringView(&lhs, 1) <= rhs; }
+inline bool operator> (QChar lhs, QStringView rhs) noexcept { return QStringView(&lhs, 1) >  rhs; }
+inline bool operator>=(QChar lhs, QStringView rhs) noexcept { return QStringView(&lhs, 1) >= rhs; }
 
 // QStringView <> QLatin1String
-inline bool operator==(QStringView lhs, QLatin1String rhs) Q_DECL_NOTHROW { return lhs.size() == rhs.size() && QtPrivate::compareStrings(lhs, rhs) == 0; }
-inline bool operator!=(QStringView lhs, QLatin1String rhs) Q_DECL_NOTHROW { return !(lhs == rhs); }
-inline bool operator< (QStringView lhs, QLatin1String rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) <  0; }
-inline bool operator<=(QStringView lhs, QLatin1String rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) <= 0; }
-inline bool operator> (QStringView lhs, QLatin1String rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) >  0; }
-inline bool operator>=(QStringView lhs, QLatin1String rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) >= 0; }
-
-inline bool operator==(QLatin1String lhs, QStringView rhs) Q_DECL_NOTHROW { return lhs.size() == rhs.size() && QtPrivate::compareStrings(lhs, rhs) == 0; }
-inline bool operator!=(QLatin1String lhs, QStringView rhs) Q_DECL_NOTHROW { return !(lhs == rhs); }
-inline bool operator< (QLatin1String lhs, QStringView rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) <  0; }
-inline bool operator<=(QLatin1String lhs, QStringView rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) <= 0; }
-inline bool operator> (QLatin1String lhs, QStringView rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) >  0; }
-inline bool operator>=(QLatin1String lhs, QStringView rhs) Q_DECL_NOTHROW { return QtPrivate::compareStrings(lhs, rhs) >= 0; }
+inline bool operator==(QStringView lhs, QLatin1String rhs) noexcept { return lhs.size() == rhs.size() && QtPrivate::compareStrings(lhs, rhs) == 0; }
+inline bool operator!=(QStringView lhs, QLatin1String rhs) noexcept { return !(lhs == rhs); }
+inline bool operator< (QStringView lhs, QLatin1String rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) <  0; }
+inline bool operator<=(QStringView lhs, QLatin1String rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) <= 0; }
+inline bool operator> (QStringView lhs, QLatin1String rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) >  0; }
+inline bool operator>=(QStringView lhs, QLatin1String rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) >= 0; }
+
+inline bool operator==(QLatin1String lhs, QStringView rhs) noexcept { return lhs.size() == rhs.size() && QtPrivate::compareStrings(lhs, rhs) == 0; }
+inline bool operator!=(QLatin1String lhs, QStringView rhs) noexcept { return !(lhs == rhs); }
+inline bool operator< (QLatin1String lhs, QStringView rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) <  0; }
+inline bool operator<=(QLatin1String lhs, QStringView rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) <= 0; }
+inline bool operator> (QLatin1String lhs, QStringView rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) >  0; }
+inline bool operator>=(QLatin1String lhs, QStringView rhs) noexcept { return QtPrivate::compareStrings(lhs, rhs) >= 0; }
 
 #if !defined(QT_NO_CAST_FROM_ASCII) && !defined(QT_RESTRICTED_CAST_FROM_ASCII)
 // QStringRef <> QByteArray
diff --git a/src/corelib/tools/qstringalgorithms.h b/src/corelib/tools/qstringalgorithms.h
index e94f725598..8e7fc0af9b 100644
--- a/src/corelib/tools/qstringalgorithms.h
+++ b/src/corelib/tools/qstringalgorithms.h
@@ -56,31 +56,31 @@ template <typename T> class QVector;
 
 namespace QtPrivate {
 
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype qustrlen(const ushort *str) Q_DECL_NOTHROW;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype qustrlen(const ushort *str) noexcept;
 Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION const ushort *qustrchr(QStringView str, ushort ch) noexcept;
 
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION int compareStrings(QStringView   lhs, QStringView   rhs, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION int compareStrings(QStringView   lhs, QLatin1String rhs, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION int compareStrings(QLatin1String lhs, QStringView   rhs, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION int compareStrings(QLatin1String lhs, QLatin1String rhs, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION int compareStrings(QStringView   lhs, QStringView   rhs, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION int compareStrings(QStringView   lhs, QLatin1String rhs, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION int compareStrings(QLatin1String lhs, QStringView   rhs, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION int compareStrings(QLatin1String lhs, QLatin1String rhs, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 
 
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool startsWith(QStringView   haystack, QStringView   needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool startsWith(QStringView   haystack, QLatin1String needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool startsWith(QLatin1String haystack, QStringView   needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool startsWith(QLatin1String haystack, QLatin1String needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool startsWith(QStringView   haystack, QStringView   needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool startsWith(QStringView   haystack, QLatin1String needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool startsWith(QLatin1String haystack, QStringView   needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool startsWith(QLatin1String haystack, QLatin1String needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool endsWith(QStringView   haystack, QStringView   needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool endsWith(QStringView   haystack, QLatin1String needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool endsWith(QLatin1String haystack, QStringView   needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool endsWith(QLatin1String haystack, QLatin1String needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool endsWith(QStringView   haystack, QStringView   needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool endsWith(QStringView   haystack, QLatin1String needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool endsWith(QLatin1String haystack, QStringView   needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool endsWith(QLatin1String haystack, QLatin1String needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findChar(QStringView str, QChar ch, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findString(QStringView haystack, qsizetype from, QStringView needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findString(QStringView haystack, qsizetype from, QLatin1String needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) Q_DECL_NOTHROW;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findChar(QStringView str, QChar ch, qsizetype from, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findString(QStringView haystack, qsizetype from, QStringView needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION qsizetype findString(QStringView haystack, qsizetype from, QLatin1String needle, Qt::CaseSensitivity cs = Qt::CaseSensitive) noexcept;
 
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION QStringView   trimmed(QStringView   s) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION QLatin1String trimmed(QLatin1String s) Q_DECL_NOTHROW;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION QStringView   trimmed(QStringView   s) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION QLatin1String trimmed(QLatin1String s) noexcept;
 
 Q_REQUIRED_RESULT Q_CORE_EXPORT QByteArray convertToLatin1(QStringView str);
 Q_REQUIRED_RESULT Q_CORE_EXPORT QByteArray convertToUtf8(QStringView str);
@@ -88,10 +88,10 @@ Q_REQUIRED_RESULT Q_CORE_EXPORT QByteArray convertToLocal8Bit(QStringView str);
 Q_REQUIRED_RESULT Q_CORE_EXPORT QVector<uint> convertToUcs4(QStringView str);
 Q_REQUIRED_RESULT Q_CORE_EXPORT bool isRightToLeft(QStringView string);
 
-Q_REQUIRED_RESULT Q_CORE_EXPORT bool isAscii(QLatin1String s) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT Q_CORE_EXPORT bool isAscii(QStringView   s) Q_DECL_NOTHROW;
-Q_REQUIRED_RESULT               bool isLatin1(QLatin1String s) Q_DECL_NOTHROW; // in qstring.h
-Q_REQUIRED_RESULT Q_CORE_EXPORT bool isLatin1(QStringView   s) Q_DECL_NOTHROW;
+Q_REQUIRED_RESULT Q_CORE_EXPORT bool isAscii(QLatin1String s) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT bool isAscii(QStringView   s) noexcept;
+Q_REQUIRED_RESULT               bool isLatin1(QLatin1String s) noexcept; // in qstring.h
+Q_REQUIRED_RESULT Q_CORE_EXPORT bool isLatin1(QStringView   s) noexcept;
 
 } // namespace QtPRivate
 
diff --git a/src/corelib/tools/qstringbuilder.cpp b/src/corelib/tools/qstringbuilder.cpp
index 8afc83819b..cf443ec369 100644
--- a/src/corelib/tools/qstringbuilder.cpp
+++ b/src/corelib/tools/qstringbuilder.cpp
@@ -124,7 +124,7 @@ QT_BEGIN_NAMESPACE
 /*!
     \internal
  */
-void QAbstractConcatenable::convertFromAscii(const char *a, int len, QChar *&out) Q_DECL_NOTHROW
+void QAbstractConcatenable::convertFromAscii(const char *a, int len, QChar *&out) noexcept
 {
     if (Q_UNLIKELY(len == -1)) {
         if (!a)
diff --git a/src/corelib/tools/qstringbuilder.h b/src/corelib/tools/qstringbuilder.h
index 1d96d70637..79ed10c7a8 100644
--- a/src/corelib/tools/qstringbuilder.h
+++ b/src/corelib/tools/qstringbuilder.h
@@ -58,12 +58,12 @@ QT_BEGIN_NAMESPACE
 struct Q_CORE_EXPORT QAbstractConcatenable
 {
 protected:
-    static void convertFromAscii(const char *a, int len, QChar *&out) Q_DECL_NOTHROW;
-    static inline void convertFromAscii(char a, QChar *&out) Q_DECL_NOTHROW
+    static void convertFromAscii(const char *a, int len, QChar *&out) noexcept;
+    static inline void convertFromAscii(char a, QChar *&out) noexcept
     {
         *out++ = QLatin1Char(a);
     }
-    static void appendLatin1To(const char *a, int len, QChar *out) Q_DECL_NOTHROW;
+    static void appendLatin1To(const char *a, int len, QChar *out) noexcept;
 };
 
 template <typename T> struct QConcatenable {};
diff --git a/src/corelib/tools/qstringlist.h b/src/corelib/tools/qstringlist.h
index b6c48488df..6387161269 100644
--- a/src/corelib/tools/qstringlist.h
+++ b/src/corelib/tools/qstringlist.h
@@ -100,11 +100,11 @@ class QStringList : public QList<QString>
 {
 #endif
 public:
-    inline QStringList() Q_DECL_NOTHROW { }
+    inline QStringList() noexcept { }
     inline explicit QStringList(const QString &i) { append(i); }
     inline QStringList(const QList<QString> &l) : QList<QString>(l) { }
 #ifdef Q_COMPILER_RVALUE_REFS
-    inline QStringList(QList<QString> &&l) Q_DECL_NOTHROW : QList<QString>(std::move(l)) { }
+    inline QStringList(QList<QString> &&l) noexcept : QList<QString>(std::move(l)) { }
 #endif
 #ifdef Q_COMPILER_INITIALIZER_LISTS
     inline QStringList(std::initializer_list<QString> args) : QList<QString>(args) { }
@@ -113,7 +113,7 @@ public:
     QStringList &operator=(const QList<QString> &other)
     { QList<QString>::operator=(other); return *this; }
 #ifdef Q_COMPILER_RVALUE_REFS
-    QStringList &operator=(QList<QString> &&other) Q_DECL_NOTHROW
+    QStringList &operator=(QList<QString> &&other) noexcept
     { QList<QString>::operator=(std::move(other)); return *this; }
 #endif
 
diff --git a/src/corelib/tools/qstringliteral.h b/src/corelib/tools/qstringliteral.h
index 64296b89fc..603f19c0b4 100644
--- a/src/corelib/tools/qstringliteral.h
+++ b/src/corelib/tools/qstringliteral.h
@@ -63,7 +63,7 @@ Q_STATIC_ASSERT_X(sizeof(qunicodechar) == 2,
 
 #define QT_UNICODE_LITERAL(str) u"" str
 #define QStringLiteral(str) \
-    ([]() Q_DECL_NOEXCEPT -> QString { \
+    ([]() noexcept -> QString { \
         enum { Size = sizeof(QT_UNICODE_LITERAL(str))/2 - 1 }; \
         static const QStaticStringData<Size> qstring_literal = { \
             Q_STATIC_STRING_DATA_HEADER_INITIALIZER(Size), \
diff --git a/src/corelib/tools/qstringview.h b/src/corelib/tools/qstringview.h
index 4a900b5e89..5b6d63b71c 100644
--- a/src/corelib/tools/qstringview.h
+++ b/src/corelib/tools/qstringview.h
@@ -139,13 +139,13 @@ private:
     using if_compatible_qstring_like = typename std::enable_if<std::is_same<T, QString>::value || std::is_same<T, QStringRef>::value, bool>::type;
 
     template <typename Char, size_t N>
-    static Q_DECL_CONSTEXPR qsizetype lengthHelperArray(const Char (&)[N]) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR qsizetype lengthHelperArray(const Char (&)[N]) noexcept
     {
         return qsizetype(N - 1);
     }
 
     template <typename Char>
-    static qsizetype lengthHelperPointer(const Char *str) Q_DECL_NOTHROW
+    static qsizetype lengthHelperPointer(const Char *str) noexcept
     {
 #if defined(Q_CC_GNU) && !defined(Q_CC_CLANG) && !defined(Q_CC_INTEL)
         if (__builtin_constant_p(*str)) {
@@ -157,21 +157,21 @@ private:
 #endif
         return QtPrivate::qustrlen(reinterpret_cast<const ushort *>(str));
     }
-    static qsizetype lengthHelperPointer(const QChar *str) Q_DECL_NOTHROW
+    static qsizetype lengthHelperPointer(const QChar *str) noexcept
     {
         return QtPrivate::qustrlen(reinterpret_cast<const ushort *>(str));
     }
 
     template <typename Char>
-    static const storage_type *castHelper(const Char *str) Q_DECL_NOTHROW
+    static const storage_type *castHelper(const Char *str) noexcept
     { return reinterpret_cast<const storage_type*>(str); }
-    static Q_DECL_CONSTEXPR const storage_type *castHelper(const storage_type *str) Q_DECL_NOTHROW
+    static Q_DECL_CONSTEXPR const storage_type *castHelper(const storage_type *str) noexcept
     { return str; }
 
 public:
-    Q_DECL_CONSTEXPR QStringView() Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR QStringView() noexcept
         : m_size(0), m_data(nullptr) {}
-    Q_DECL_CONSTEXPR QStringView(std::nullptr_t) Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR QStringView(std::nullptr_t) noexcept
         : QStringView() {}
 
     template <typename Char, if_compatible_char<Char> = true>
@@ -185,38 +185,38 @@ public:
 
 #ifdef Q_CLANG_QDOC
     template <typename Char, size_t N>
-    Q_DECL_CONSTEXPR QStringView(const Char (&array)[N]) Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR QStringView(const Char (&array)[N]) noexcept;
 
     template <typename Char>
-    Q_DECL_CONSTEXPR QStringView(const Char *str) Q_DECL_NOTHROW;
+    Q_DECL_CONSTEXPR QStringView(const Char *str) noexcept;
 #else
     template <typename Array, if_compatible_array<Array> = true>
-    Q_DECL_CONSTEXPR QStringView(const Array &str) Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR QStringView(const Array &str) noexcept
         : QStringView(str, lengthHelperArray(str)) {}
 
     template <typename Pointer, if_compatible_pointer<Pointer> = true>
-    Q_DECL_CONSTEXPR QStringView(const Pointer &str) Q_DECL_NOTHROW
+    Q_DECL_CONSTEXPR QStringView(const Pointer &str) noexcept
         : QStringView(str, str ? lengthHelperPointer(str) : 0) {}
 #endif
 
 #ifdef Q_CLANG_QDOC
-    QStringView(const QString &str) Q_DECL_NOTHROW;
-    QStringView(const QStringRef &str) Q_DECL_NOTHROW;
+    QStringView(const QString &str) noexcept;
+    QStringView(const QStringRef &str) noexcept;
 #else
     template <typename String, if_compatible_qstring_like<String> = true>
-    QStringView(const String &str) Q_DECL_NOTHROW
+    QStringView(const String &str) noexcept
         : QStringView(str.isNull() ? nullptr : str.data(), qsizetype(str.size())) {}
 #endif
 
     template <typename StdBasicString, if_compatible_string<StdBasicString> = true>
-    QStringView(const StdBasicString &str) Q_DECL_NOTHROW
+    QStringView(const StdBasicString &str) noexcept
         : QStringView(str.data(), qsizetype(str.size())) {}
 
     Q_REQUIRED_RESULT inline QString toString() const; // defined in qstring.h
 
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR qsizetype size() const Q_DECL_NOTHROW { return m_size; }
-    Q_REQUIRED_RESULT const_pointer data() const Q_DECL_NOTHROW { return reinterpret_cast<const_pointer>(m_data); }
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR const storage_type *utf16() const Q_DECL_NOTHROW { return m_data; }
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR qsizetype size() const noexcept { return m_size; }
+    Q_REQUIRED_RESULT const_pointer data() const noexcept { return reinterpret_cast<const_pointer>(m_data); }
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR const storage_type *utf16() const noexcept { return m_data; }
 
     Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QChar operator[](qsizetype n) const
     { return Q_ASSERT(n >= 0), Q_ASSERT(n < size()), QChar(m_data[n]); }
@@ -248,28 +248,28 @@ public:
     Q_DECL_RELAXED_CONSTEXPR void chop(qsizetype n)
     { Q_ASSERT(n >= 0); Q_ASSERT(n <= size()); m_size -= n; }
 
-    Q_REQUIRED_RESULT QStringView trimmed() const Q_DECL_NOTHROW { return QtPrivate::trimmed(*this); }
+    Q_REQUIRED_RESULT QStringView trimmed() const noexcept { return QtPrivate::trimmed(*this); }
 
-    Q_REQUIRED_RESULT int compare(QStringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT int compare(QStringView other, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::compareStrings(*this, other, cs); }
 
-    Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool startsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::startsWith(*this, s, cs); }
-    Q_REQUIRED_RESULT inline bool startsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT bool startsWith(QChar c) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline bool startsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
+    Q_REQUIRED_RESULT bool startsWith(QChar c) const noexcept
     { return !empty() && front() == c; }
-    Q_REQUIRED_RESULT bool startsWith(QChar c, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool startsWith(QChar c, Qt::CaseSensitivity cs) const noexcept
     { return QtPrivate::startsWith(*this, QStringView(&c, 1), cs); }
 
-    Q_REQUIRED_RESULT bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool endsWith(QStringView s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept
     { return QtPrivate::endsWith(*this, s, cs); }
-    Q_REQUIRED_RESULT inline bool endsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const Q_DECL_NOTHROW;
-    Q_REQUIRED_RESULT bool endsWith(QChar c) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline bool endsWith(QLatin1String s, Qt::CaseSensitivity cs = Qt::CaseSensitive) const noexcept;
+    Q_REQUIRED_RESULT bool endsWith(QChar c) const noexcept
     { return !empty() && back() == c; }
-    Q_REQUIRED_RESULT bool endsWith(QChar c, Qt::CaseSensitivity cs) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool endsWith(QChar c, Qt::CaseSensitivity cs) const noexcept
     { return QtPrivate::endsWith(*this, QStringView(&c, 1), cs); }
 
-    Q_REQUIRED_RESULT bool isRightToLeft() const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT bool isRightToLeft() const noexcept
     { return QtPrivate::isRightToLeft(*this); }
 
     Q_REQUIRED_RESULT Q_CORE_EXPORT int toWCharArray(wchar_t *array) const;
@@ -277,24 +277,24 @@ public:
     //
     // STL compatibility API:
     //
-    Q_REQUIRED_RESULT const_iterator begin()   const Q_DECL_NOTHROW { return data(); }
-    Q_REQUIRED_RESULT const_iterator end()     const Q_DECL_NOTHROW { return data() + size(); }
-    Q_REQUIRED_RESULT const_iterator cbegin()  const Q_DECL_NOTHROW { return begin(); }
-    Q_REQUIRED_RESULT const_iterator cend()    const Q_DECL_NOTHROW { return end(); }
-    Q_REQUIRED_RESULT const_reverse_iterator rbegin()  const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    Q_REQUIRED_RESULT const_reverse_iterator rend()    const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
-    Q_REQUIRED_RESULT const_reverse_iterator crbegin() const Q_DECL_NOTHROW { return rbegin(); }
-    Q_REQUIRED_RESULT const_reverse_iterator crend()   const Q_DECL_NOTHROW { return rend(); }
-
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool empty() const Q_DECL_NOTHROW { return size() == 0; }
+    Q_REQUIRED_RESULT const_iterator begin()   const noexcept { return data(); }
+    Q_REQUIRED_RESULT const_iterator end()     const noexcept { return data() + size(); }
+    Q_REQUIRED_RESULT const_iterator cbegin()  const noexcept { return begin(); }
+    Q_REQUIRED_RESULT const_iterator cend()    const noexcept { return end(); }
+    Q_REQUIRED_RESULT const_reverse_iterator rbegin()  const noexcept { return const_reverse_iterator(end()); }
+    Q_REQUIRED_RESULT const_reverse_iterator rend()    const noexcept { return const_reverse_iterator(begin()); }
+    Q_REQUIRED_RESULT const_reverse_iterator crbegin() const noexcept { return rbegin(); }
+    Q_REQUIRED_RESULT const_reverse_iterator crend()   const noexcept { return rend(); }
+
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool empty() const noexcept { return size() == 0; }
     Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QChar front() const { return Q_ASSERT(!empty()), QChar(m_data[0]); }
     Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QChar back()  const { return Q_ASSERT(!empty()), QChar(m_data[m_size - 1]); }
 
     //
     // Qt compatibility API:
     //
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool isNull() const Q_DECL_NOTHROW { return !m_data; }
-    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool isEmpty() const Q_DECL_NOTHROW { return empty(); }
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool isNull() const noexcept { return !m_data; }
+    Q_REQUIRED_RESULT Q_DECL_CONSTEXPR bool isEmpty() const noexcept { return empty(); }
     Q_REQUIRED_RESULT Q_DECL_CONSTEXPR int length() const /* not nothrow! */
     { return Q_ASSERT(int(size()) == size()), int(size()); }
     Q_REQUIRED_RESULT Q_DECL_CONSTEXPR QChar first() const { return front(); }
@@ -308,7 +308,7 @@ Q_DECLARE_TYPEINFO(QStringView, Q_PRIMITIVE_TYPE);
 template <typename QStringLike, typename std::enable_if<
     std::is_same<QStringLike, QString>::value || std::is_same<QStringLike, QStringRef>::value,
     bool>::type = true>
-inline QStringView qToStringViewIgnoringNull(const QStringLike &s) Q_DECL_NOTHROW
+inline QStringView qToStringViewIgnoringNull(const QStringLike &s) noexcept
 { return QStringView(s.data(), s.size()); }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/tools/qtimezone.cpp b/src/corelib/tools/qtimezone.cpp
index cbc6b50c98..ef323de14a 100644
--- a/src/corelib/tools/qtimezone.cpp
+++ b/src/corelib/tools/qtimezone.cpp
@@ -317,7 +317,7 @@ Q_GLOBAL_STATIC(QTimeZoneSingleton, global_tz);
     Create a null/invalid time zone instance.
 */
 
-QTimeZone::QTimeZone() Q_DECL_NOTHROW
+QTimeZone::QTimeZone() noexcept
     : d(0)
 {
 }
diff --git a/src/corelib/tools/qtimezone.h b/src/corelib/tools/qtimezone.h
index 29d8a4dbe5..ca98986ec1 100644
--- a/src/corelib/tools/qtimezone.h
+++ b/src/corelib/tools/qtimezone.h
@@ -89,7 +89,7 @@ public:
     };
     typedef QVector<OffsetData> OffsetDataList;
 
-    QTimeZone() Q_DECL_NOTHROW;
+    QTimeZone() noexcept;
     explicit QTimeZone(const QByteArray &ianaId);
     explicit QTimeZone(int offsetSeconds);
     /*implicit*/ QTimeZone(const QByteArray &zoneId, int offsetSeconds, const QString &name,
@@ -100,10 +100,10 @@ public:
 
     QTimeZone &operator=(const QTimeZone &other);
  #ifdef Q_COMPILER_RVALUE_REFS
-    QTimeZone &operator=(QTimeZone &&other) Q_DECL_NOTHROW { swap(other); return *this; }
+    QTimeZone &operator=(QTimeZone &&other) noexcept { swap(other); return *this; }
 #endif
 
-    void swap(QTimeZone &other) Q_DECL_NOTHROW
+    void swap(QTimeZone &other) noexcept
     { d.swap(other.d); }
 
     bool operator==(const QTimeZone &other) const;
diff --git a/src/corelib/tools/qtimezoneprivate_p.h b/src/corelib/tools/qtimezoneprivate_p.h
index 24a9a00f11..b5e9286f6a 100644
--- a/src/corelib/tools/qtimezoneprivate_p.h
+++ b/src/corelib/tools/qtimezoneprivate_p.h
@@ -282,9 +282,9 @@ struct QTzTransitionRule
     quint8 abbreviationIndex;
 };
 Q_DECLARE_TYPEINFO(QTzTransitionRule, Q_PRIMITIVE_TYPE);
-Q_DECL_CONSTEXPR inline bool operator==(const QTzTransitionRule &lhs, const QTzTransitionRule &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator==(const QTzTransitionRule &lhs, const QTzTransitionRule &rhs) noexcept
 { return lhs.stdOffset == rhs.stdOffset && lhs.dstOffset == rhs.dstOffset && lhs.abbreviationIndex == rhs.abbreviationIndex; }
-Q_DECL_CONSTEXPR inline bool operator!=(const QTzTransitionRule &lhs, const QTzTransitionRule &rhs) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline bool operator!=(const QTzTransitionRule &lhs, const QTzTransitionRule &rhs) noexcept
 { return !operator==(lhs, rhs); }
 
 class Q_AUTOTEST_EXPORT QTzTimeZonePrivate final : public QTimeZonePrivate
diff --git a/src/corelib/tools/qtimezoneprivate_tz.cpp b/src/corelib/tools/qtimezoneprivate_tz.cpp
index f75a61977d..6105c93a23 100644
--- a/src/corelib/tools/qtimezoneprivate_tz.cpp
+++ b/src/corelib/tools/qtimezoneprivate_tz.cpp
@@ -467,7 +467,7 @@ struct PosixZone
     static PosixZone invalid() { return {QString(), InvalidOffset}; }
     static PosixZone parse(const char *&pos, const char *end);
 
-    bool hasValidOffset() const Q_DECL_NOTHROW { return offset != InvalidOffset; }
+    bool hasValidOffset() const noexcept { return offset != InvalidOffset; }
 };
 
 } // unnamed namespace
diff --git a/src/corelib/tools/qtools_p.h b/src/corelib/tools/qtools_p.h
index 17d2ab852a..b239987871 100644
--- a/src/corelib/tools/qtools_p.h
+++ b/src/corelib/tools/qtools_p.h
@@ -57,17 +57,17 @@
 QT_BEGIN_NAMESPACE
 
 namespace QtMiscUtils {
-Q_DECL_CONSTEXPR inline char toHexUpper(uint value) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline char toHexUpper(uint value) noexcept
 {
     return "0123456789ABCDEF"[value & 0xF];
 }
 
-Q_DECL_CONSTEXPR inline char toHexLower(uint value) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline char toHexLower(uint value) noexcept
 {
     return "0123456789abcdef"[value & 0xF];
 }
 
-Q_DECL_CONSTEXPR inline int fromHex(uint c) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int fromHex(uint c) noexcept
 {
     return ((c >= '0') && (c <= '9')) ? int(c - '0') :
            ((c >= 'A') && (c <= 'F')) ? int(c - 'A' + 10) :
@@ -75,12 +75,12 @@ Q_DECL_CONSTEXPR inline int fromHex(uint c) Q_DECL_NOTHROW
            /* otherwise */              -1;
 }
 
-Q_DECL_CONSTEXPR inline char toOct(uint value) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline char toOct(uint value) noexcept
 {
     return '0' + char(value & 0x7);
 }
 
-Q_DECL_CONSTEXPR inline int fromOct(uint c) Q_DECL_NOTHROW
+Q_DECL_CONSTEXPR inline int fromOct(uint c) noexcept
 {
     return ((c >= '0') && (c <= '7')) ? int(c - '0') : -1;
 }
@@ -98,9 +98,9 @@ struct CalculateGrowingBlockSizeResult {
 
 // implemented in qbytearray.cpp
 size_t Q_CORE_EXPORT Q_DECL_CONST_FUNCTION
-qCalculateBlockSize(size_t elementCount, size_t elementSize, size_t headerSize = 0) Q_DECL_NOTHROW;
+qCalculateBlockSize(size_t elementCount, size_t elementSize, size_t headerSize = 0) noexcept;
 CalculateGrowingBlockSizeResult Q_CORE_EXPORT Q_DECL_CONST_FUNCTION
-qCalculateGrowingBlockSize(size_t elementCount, size_t elementSize, size_t headerSize = 0) Q_DECL_NOTHROW ;
+qCalculateGrowingBlockSize(size_t elementCount, size_t elementSize, size_t headerSize = 0) noexcept ;
 
 QT_END_NAMESPACE
 
diff --git a/src/corelib/tools/qunicodetables.cpp b/src/corelib/tools/qunicodetables.cpp
index 4c4821802d..d57b39ff1f 100644
--- a/src/corelib/tools/qunicodetables.cpp
+++ b/src/corelib/tools/qunicodetables.cpp
@@ -8803,42 +8803,42 @@ static const Properties uc_properties[] = {
     { 12, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 12, 0 }
 };
 
-Q_DECL_CONST_FUNCTION static inline const Properties *qGetProp(uint ucs4) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION static inline const Properties *qGetProp(uint ucs4) noexcept
 {
     return uc_properties + GET_PROP_INDEX(ucs4);
 }
 
-Q_DECL_CONST_FUNCTION static inline const Properties *qGetProp(ushort ucs2) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION static inline const Properties *qGetProp(ushort ucs2) noexcept
 {
     return uc_properties + GET_PROP_INDEX_UCS2(ucs2);
 }
 
-Q_DECL_CONST_FUNCTION Q_CORE_EXPORT const Properties * QT_FASTCALL properties(uint ucs4) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION Q_CORE_EXPORT const Properties * QT_FASTCALL properties(uint ucs4) noexcept
 {
     return qGetProp(ucs4);
 }
 
-Q_DECL_CONST_FUNCTION Q_CORE_EXPORT const Properties * QT_FASTCALL properties(ushort ucs2) Q_DECL_NOTHROW
+Q_DECL_CONST_FUNCTION Q_CORE_EXPORT const Properties * QT_FASTCALL properties(ushort ucs2) noexcept
 {
     return qGetProp(ucs2);
 }
 
-Q_CORE_EXPORT GraphemeBreakClass QT_FASTCALL graphemeBreakClass(uint ucs4) Q_DECL_NOTHROW
+Q_CORE_EXPORT GraphemeBreakClass QT_FASTCALL graphemeBreakClass(uint ucs4) noexcept
 {
     return static_cast<GraphemeBreakClass>(qGetProp(ucs4)->graphemeBreakClass);
 }
 
-Q_CORE_EXPORT WordBreakClass QT_FASTCALL wordBreakClass(uint ucs4) Q_DECL_NOTHROW
+Q_CORE_EXPORT WordBreakClass QT_FASTCALL wordBreakClass(uint ucs4) noexcept
 {
     return static_cast<WordBreakClass>(qGetProp(ucs4)->wordBreakClass);
 }
 
-Q_CORE_EXPORT SentenceBreakClass QT_FASTCALL sentenceBreakClass(uint ucs4) Q_DECL_NOTHROW
+Q_CORE_EXPORT SentenceBreakClass QT_FASTCALL sentenceBreakClass(uint ucs4) noexcept
 {
     return static_cast<SentenceBreakClass>(qGetProp(ucs4)->sentenceBreakClass);
 }
 
-Q_CORE_EXPORT LineBreakClass QT_FASTCALL lineBreakClass(uint ucs4) Q_DECL_NOTHROW
+Q_CORE_EXPORT LineBreakClass QT_FASTCALL lineBreakClass(uint ucs4) noexcept
 {
     return static_cast<LineBreakClass>(qGetProp(ucs4)->lineBreakClass);
 }
diff --git a/src/corelib/tools/qunicodetables_p.h b/src/corelib/tools/qunicodetables_p.h
index 3f2e91a9b2..cb7a211cb6 100644
--- a/src/corelib/tools/qunicodetables_p.h
+++ b/src/corelib/tools/qunicodetables_p.h
@@ -93,8 +93,8 @@ struct Properties {
     ushort script              : 8;
 };
 
-Q_CORE_EXPORT const Properties * QT_FASTCALL properties(uint ucs4) Q_DECL_NOTHROW;
-Q_CORE_EXPORT const Properties * QT_FASTCALL properties(ushort ucs2) Q_DECL_NOTHROW;
+Q_CORE_EXPORT const Properties * QT_FASTCALL properties(uint ucs4) noexcept;
+Q_CORE_EXPORT const Properties * QT_FASTCALL properties(ushort ucs2) noexcept;
 
 struct LowercaseTraits
 {
@@ -209,20 +209,20 @@ enum LineBreakClass {
     NumLineBreakClasses
 };
 
-Q_CORE_EXPORT GraphemeBreakClass QT_FASTCALL graphemeBreakClass(uint ucs4) Q_DECL_NOTHROW;
-inline GraphemeBreakClass graphemeBreakClass(QChar ch) Q_DECL_NOTHROW
+Q_CORE_EXPORT GraphemeBreakClass QT_FASTCALL graphemeBreakClass(uint ucs4) noexcept;
+inline GraphemeBreakClass graphemeBreakClass(QChar ch) noexcept
 { return graphemeBreakClass(ch.unicode()); }
 
-Q_CORE_EXPORT WordBreakClass QT_FASTCALL wordBreakClass(uint ucs4) Q_DECL_NOTHROW;
-inline WordBreakClass wordBreakClass(QChar ch) Q_DECL_NOTHROW
+Q_CORE_EXPORT WordBreakClass QT_FASTCALL wordBreakClass(uint ucs4) noexcept;
+inline WordBreakClass wordBreakClass(QChar ch) noexcept
 { return wordBreakClass(ch.unicode()); }
 
-Q_CORE_EXPORT SentenceBreakClass QT_FASTCALL sentenceBreakClass(uint ucs4) Q_DECL_NOTHROW;
-inline SentenceBreakClass sentenceBreakClass(QChar ch) Q_DECL_NOTHROW
+Q_CORE_EXPORT SentenceBreakClass QT_FASTCALL sentenceBreakClass(uint ucs4) noexcept;
+inline SentenceBreakClass sentenceBreakClass(QChar ch) noexcept
 { return sentenceBreakClass(ch.unicode()); }
 
-Q_CORE_EXPORT LineBreakClass QT_FASTCALL lineBreakClass(uint ucs4) Q_DECL_NOTHROW;
-inline LineBreakClass lineBreakClass(QChar ch) Q_DECL_NOTHROW
+Q_CORE_EXPORT LineBreakClass QT_FASTCALL lineBreakClass(uint ucs4) noexcept;
+inline LineBreakClass lineBreakClass(QChar ch) noexcept
 { return lineBreakClass(ch.unicode()); }
 
 } // namespace QUnicodeTables
diff --git a/src/corelib/tools/qvector.h b/src/corelib/tools/qvector.h
index 9762ec1b5b..2de21e92fa 100644
--- a/src/corelib/tools/qvector.h
+++ b/src/corelib/tools/qvector.h
@@ -65,18 +65,18 @@ class QVector
     Data *d;
 
 public:
-    inline QVector() Q_DECL_NOTHROW : d(Data::sharedNull()) { }
+    inline QVector() noexcept : d(Data::sharedNull()) { }
     explicit QVector(int size);
     QVector(int size, const T &t);
     inline QVector(const QVector<T> &v);
     inline ~QVector() { if (!d->ref.deref()) freeData(d); }
     QVector<T> &operator=(const QVector<T> &v);
 #if defined(Q_COMPILER_RVALUE_REFS) || defined(Q_CLANG_QDOC)
-    QVector(QVector<T> &&other) Q_DECL_NOTHROW : d(other.d) { other.d = Data::sharedNull(); }
-    QVector<T> &operator=(QVector<T> &&other) Q_DECL_NOTHROW
+    QVector(QVector<T> &&other) noexcept : d(other.d) { other.d = Data::sharedNull(); }
+    QVector<T> &operator=(QVector<T> &&other) noexcept
     { QVector moved(std::move(other)); swap(moved); return *this; }
 #endif
-    void swap(QVector<T> &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+    void swap(QVector<T> &other) noexcept { qSwap(d, other.d); }
 #ifdef Q_COMPILER_INITIALIZER_LISTS
     inline QVector(std::initializer_list<T> args);
     QVector<T> &operator=(std::initializer_list<T> args);
@@ -209,29 +209,29 @@ public:
     typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
 #if !defined(QT_STRICT_ITERATORS) || defined(Q_CLANG_QDOC)
     inline iterator begin() { detach(); return d->begin(); }
-    inline const_iterator begin() const Q_DECL_NOTHROW { return d->constBegin(); }
-    inline const_iterator cbegin() const Q_DECL_NOTHROW { return d->constBegin(); }
-    inline const_iterator constBegin() const Q_DECL_NOTHROW { return d->constBegin(); }
+    inline const_iterator begin() const noexcept { return d->constBegin(); }
+    inline const_iterator cbegin() const noexcept { return d->constBegin(); }
+    inline const_iterator constBegin() const noexcept { return d->constBegin(); }
     inline iterator end() { detach(); return d->end(); }
-    inline const_iterator end() const Q_DECL_NOTHROW { return d->constEnd(); }
-    inline const_iterator cend() const Q_DECL_NOTHROW { return d->constEnd(); }
-    inline const_iterator constEnd() const Q_DECL_NOTHROW { return d->constEnd(); }
+    inline const_iterator end() const noexcept { return d->constEnd(); }
+    inline const_iterator cend() const noexcept { return d->constEnd(); }
+    inline const_iterator constEnd() const noexcept { return d->constEnd(); }
 #else
     inline iterator begin(iterator = iterator()) { detach(); return d->begin(); }
-    inline const_iterator begin(const_iterator = const_iterator()) const Q_DECL_NOTHROW { return d->constBegin(); }
-    inline const_iterator cbegin(const_iterator = const_iterator()) const Q_DECL_NOTHROW { return d->constBegin(); }
-    inline const_iterator constBegin(const_iterator = const_iterator()) const Q_DECL_NOTHROW { return d->constBegin(); }
+    inline const_iterator begin(const_iterator = const_iterator()) const noexcept { return d->constBegin(); }
+    inline const_iterator cbegin(const_iterator = const_iterator()) const noexcept { return d->constBegin(); }
+    inline const_iterator constBegin(const_iterator = const_iterator()) const noexcept { return d->constBegin(); }
     inline iterator end(iterator = iterator()) { detach(); return d->end(); }
-    inline const_iterator end(const_iterator = const_iterator()) const Q_DECL_NOTHROW { return d->constEnd(); }
-    inline const_iterator cend(const_iterator = const_iterator()) const Q_DECL_NOTHROW { return d->constEnd(); }
-    inline const_iterator constEnd(const_iterator = const_iterator()) const Q_DECL_NOTHROW { return d->constEnd(); }
+    inline const_iterator end(const_iterator = const_iterator()) const noexcept { return d->constEnd(); }
+    inline const_iterator cend(const_iterator = const_iterator()) const noexcept { return d->constEnd(); }
+    inline const_iterator constEnd(const_iterator = const_iterator()) const noexcept { return d->constEnd(); }
 #endif
     reverse_iterator rbegin() { return reverse_iterator(end()); }
     reverse_iterator rend() { return reverse_iterator(begin()); }
-    const_reverse_iterator rbegin() const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    const_reverse_iterator rend() const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
-    const_reverse_iterator crbegin() const Q_DECL_NOTHROW { return const_reverse_iterator(end()); }
-    const_reverse_iterator crend() const Q_DECL_NOTHROW { return const_reverse_iterator(begin()); }
+    const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
+    const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
+    const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
+    const_reverse_iterator crend() const noexcept { return const_reverse_iterator(begin()); }
     iterator insert(iterator before, int n, const T &x);
     inline iterator insert(iterator before, const T &x) { return insert(before, 1, x); }
     inline iterator insert(iterator before, T &&x);
diff --git a/src/corelib/tools/qversionnumber.cpp b/src/corelib/tools/qversionnumber.cpp
index b96e48252e..6fcb9f50e9 100644
--- a/src/corelib/tools/qversionnumber.cpp
+++ b/src/corelib/tools/qversionnumber.cpp
@@ -235,7 +235,7 @@ QVersionNumber QVersionNumber::normalized() const
 
     \sa commonPrefix()
 */
-bool QVersionNumber::isPrefixOf(const QVersionNumber &other) const Q_DECL_NOTHROW
+bool QVersionNumber::isPrefixOf(const QVersionNumber &other) const noexcept
 {
     if (segmentCount() > other.segmentCount())
         return false;
@@ -259,7 +259,7 @@ bool QVersionNumber::isPrefixOf(const QVersionNumber &other) const Q_DECL_NOTHRO
 
     \snippet qversionnumber/main.cpp 1
 */
-int QVersionNumber::compare(const QVersionNumber &v1, const QVersionNumber &v2) Q_DECL_NOTHROW
+int QVersionNumber::compare(const QVersionNumber &v1, const QVersionNumber &v2) noexcept
 {
     int commonlen;
 
diff --git a/src/corelib/tools/qversionnumber.h b/src/corelib/tools/qversionnumber.h
index 1bfb4aab39..d51947c091 100644
--- a/src/corelib/tools/qversionnumber.h
+++ b/src/corelib/tools/qversionnumber.h
@@ -87,7 +87,7 @@ class QVersionNumber
         };
 
         // set the InlineSegmentMarker and set length to zero
-        SegmentStorage() Q_DECL_NOTHROW : dummy(1) {}
+        SegmentStorage() noexcept : dummy(1) {}
 
         SegmentStorage(const QVector<int> &seg)
         {
@@ -120,13 +120,13 @@ class QVersionNumber
         }
 
 #ifdef Q_COMPILER_RVALUE_REFS
-        SegmentStorage(SegmentStorage &&other) Q_DECL_NOTHROW
+        SegmentStorage(SegmentStorage &&other) noexcept
             : dummy(other.dummy)
         {
             other.dummy = 1;
         }
 
-        SegmentStorage &operator=(SegmentStorage &&other) Q_DECL_NOTHROW
+        SegmentStorage &operator=(SegmentStorage &&other) noexcept
         {
             qSwap(dummy, other.dummy);
             return *this;
@@ -153,10 +153,10 @@ class QVersionNumber
 
         ~SegmentStorage() { if (isUsingPointer()) delete pointer_segments; }
 
-        bool isUsingPointer() const Q_DECL_NOTHROW
+        bool isUsingPointer() const noexcept
         { return (inline_segments[InlineSegmentMarker] & 1) == 0; }
 
-        int size() const Q_DECL_NOTHROW
+        int size() const noexcept
         { return isUsingPointer() ? pointer_segments->size() : (inline_segments[InlineSegmentMarker] >> 1); }
 
         void setInlineSize(int len)
@@ -218,7 +218,7 @@ class QVersionNumber
     } m_segments;
 
 public:
-    inline QVersionNumber() Q_DECL_NOTHROW
+    inline QVersionNumber() noexcept
         : m_segments()
     {}
     inline explicit QVersionNumber(const QVector<int> &seg)
@@ -248,34 +248,34 @@ public:
     inline explicit QVersionNumber(int maj, int min, int mic)
     { m_segments.setSegments(3, maj, min, mic); }
 
-    Q_REQUIRED_RESULT inline bool isNull() const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline bool isNull() const noexcept
     { return segmentCount() == 0; }
 
-    Q_REQUIRED_RESULT inline bool isNormalized() const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline bool isNormalized() const noexcept
     { return isNull() || segmentAt(segmentCount() - 1) != 0; }
 
-    Q_REQUIRED_RESULT inline int majorVersion() const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline int majorVersion() const noexcept
     { return segmentAt(0); }
 
-    Q_REQUIRED_RESULT inline int minorVersion() const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline int minorVersion() const noexcept
     { return segmentAt(1); }
 
-    Q_REQUIRED_RESULT inline int microVersion() const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline int microVersion() const noexcept
     { return segmentAt(2); }
 
     Q_REQUIRED_RESULT Q_CORE_EXPORT QVersionNumber normalized() const;
 
     Q_REQUIRED_RESULT Q_CORE_EXPORT QVector<int> segments() const;
 
-    Q_REQUIRED_RESULT inline int segmentAt(int index) const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline int segmentAt(int index) const noexcept
     { return (m_segments.size() > index) ? m_segments.at(index) : 0; }
 
-    Q_REQUIRED_RESULT inline int segmentCount() const Q_DECL_NOTHROW
+    Q_REQUIRED_RESULT inline int segmentCount() const noexcept
     { return m_segments.size(); }
 
-    Q_REQUIRED_RESULT Q_CORE_EXPORT bool isPrefixOf(const QVersionNumber &other) const Q_DECL_NOTHROW;
+    Q_REQUIRED_RESULT Q_CORE_EXPORT bool isPrefixOf(const QVersionNumber &other) const noexcept;
 
-    Q_REQUIRED_RESULT Q_CORE_EXPORT static int compare(const QVersionNumber &v1, const QVersionNumber &v2) Q_DECL_NOTHROW;
+    Q_REQUIRED_RESULT Q_CORE_EXPORT static int compare(const QVersionNumber &v1, const QVersionNumber &v2) noexcept;
 
     Q_REQUIRED_RESULT Q_CORE_EXPORT static Q_DECL_PURE_FUNCTION QVersionNumber commonPrefix(const QVersionNumber &v1, const QVersionNumber &v2);
 
@@ -299,22 +299,22 @@ Q_DECLARE_TYPEINFO(QVersionNumber, Q_MOVABLE_TYPE);
 Q_CORE_EXPORT QDebug operator<<(QDebug, const QVersionNumber &version);
 #endif
 
-Q_REQUIRED_RESULT inline bool operator> (const QVersionNumber &lhs, const QVersionNumber &rhs) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool operator> (const QVersionNumber &lhs, const QVersionNumber &rhs) noexcept
 { return QVersionNumber::compare(lhs, rhs) > 0; }
 
-Q_REQUIRED_RESULT inline bool operator>=(const QVersionNumber &lhs, const QVersionNumber &rhs) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool operator>=(const QVersionNumber &lhs, const QVersionNumber &rhs) noexcept
 { return QVersionNumber::compare(lhs, rhs) >= 0; }
 
-Q_REQUIRED_RESULT inline bool operator< (const QVersionNumber &lhs, const QVersionNumber &rhs) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool operator< (const QVersionNumber &lhs, const QVersionNumber &rhs) noexcept
 { return QVersionNumber::compare(lhs, rhs) < 0; }
 
-Q_REQUIRED_RESULT inline bool operator<=(const QVersionNumber &lhs, const QVersionNumber &rhs) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool operator<=(const QVersionNumber &lhs, const QVersionNumber &rhs) noexcept
 { return QVersionNumber::compare(lhs, rhs) <= 0; }
 
-Q_REQUIRED_RESULT inline bool operator==(const QVersionNumber &lhs, const QVersionNumber &rhs) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool operator==(const QVersionNumber &lhs, const QVersionNumber &rhs) noexcept
 { return QVersionNumber::compare(lhs, rhs) == 0; }
 
-Q_REQUIRED_RESULT inline bool operator!=(const QVersionNumber &lhs, const QVersionNumber &rhs) Q_DECL_NOTHROW
+Q_REQUIRED_RESULT inline bool operator!=(const QVersionNumber &lhs, const QVersionNumber &rhs) noexcept
 { return QVersionNumber::compare(lhs, rhs) != 0; }
 
 QT_END_NAMESPACE