AST Matcher Reference

Matches constructor initializers.

Examples matches i(42).
  class C {
    C() : i(42) {}
    int i;
  };

Matches C++ access specifier declarations.

Given
  class C {
  public:
    int a;
  };
accessSpecDecl()
  matches 'public:'

Matches C++ class template declarations.

Example matches Z
  template<class T> class Z {};

Matches C++ class template specializations.

Given
  template<typename T> class A {};
  template<> class A<double> {};
  A<int> a;
classTemplateSpecializationDecl()
  matches the specializations A<int> and A<double>

Matches C++ constructor declarations.

Example matches Foo::Foo() and Foo::Foo(int)
  class Foo {
   public:
    Foo();
    Foo(int);
    int DoSomething();
  };

Matches conversion operator declarations.

Example matches the operator.
  class X { operator int() const; };

Matches explicit C++ destructor declarations.

Example matches Foo::~Foo()
  class Foo {
   public:
    virtual ~Foo();
  };

Matches method declarations.

Example matches y
  class X { void y(); };

Matches C++ class declarations.

Example matches X, Z
  class X;
  template<class T> class Z {};

Matches declarations.

Examples matches X, C, and the friend declaration inside C;
  void X();
  class C {
    friend X;
  };

Matches declarator declarations (field, variable, function
and non-type template parameter declarations).

Given
  class X { int y; };
declaratorDecl()
  matches int y.

Matches enum constants.

Example matches A, B, C
  enum X {
    A, B, C
  };

Matches enum declarations.

Example matches X
  enum X {
    A, B, C
  };

Matches field declarations.

Given
  class X { int m; };
fieldDecl()
  matches 'm'.

Matches friend declarations.

Given
  class X { friend void foo(); };
friendDecl()
  matches 'friend void foo()'.

Matches function declarations.

Example matches f
  void f();

Matches C++ function template declarations.

Example matches f
  template<class T> void f(T t) {}

Matches a declaration of a linkage specification.

Given
  extern "C" {}
linkageSpecDecl()
  matches "extern "C" {}"

Matches a declaration of anything that could have a name.

Example matches X, S, the anonymous union type, i, and U;
  typedef int X;
  struct S {
    union {
      int i;
    } U;
  };

Matches a declaration of a namespace alias.

Given
  namespace test {}
  namespace alias = ::test;
namespaceAliasDecl()
  matches "namespace alias" but not "namespace test"

Matches a declaration of a namespace.

Given
  namespace {}
  namespace test {}
namespaceDecl()
  matches "namespace {}" and "namespace test {}"

Matches non-type template parameter declarations.

Given
  template <typename T, int N> struct C {};
nonTypeTemplateParmDecl()
  matches 'N', but not 'T'.

Matches Objective-C interface declarations.

Example matches Foo
  @interface Foo
  @end

Matches parameter variable declarations.

Given
  void f(int x);
parmVarDecl()
  matches int x.

Matches class, struct, and union declarations.

Example matches X, Z, U, and S
  class X;
  template<class T> class Z {};
  struct S {};
  union U {};

Matches a C++ static_assert declaration.

Example:
  staticAssertExpr()
matches
  static_assert(sizeof(S) == sizeof(int))
in
  struct S {
    int x;
  };
  static_assert(sizeof(S) == sizeof(int));

Matches template type parameter declarations.

Given
  template <typename T, int N> struct C {};
templateTypeParmDecl()
  matches 'T', but not 'N'.

Matches the top declaration context.

Given
  int X;
  namespace NS {
  int Y;
  }  namespace NS
decl(hasDeclContext(translationUnitDecl()))
  matches "int X", but not "int Y".

Matches typedef declarations.

Given
  typedef int X;
typedefDecl()
  matches "typedef int X"

Matches unresolved using value declarations that involve the
typename.

Given
  template <typename T>
  struct Base { typedef T Foo; };

  template<typename T>
  struct S : private Base<T> {
    using typename Base<T>::Foo;
  };
unresolvedUsingTypenameDecl()
  matches using Base<T>::Foo 

Matches unresolved using value declarations.

Given
  template<typename X>
  class C : private X {
    using X::x;
  };
unresolvedUsingValueDecl()
  matches using X::x 

Matches using declarations.

Given
  namespace X { int x; }
  using X::x;
usingDecl()
  matches using X::x 

Matches using namespace declarations.

Given
  namespace X { int x; }
  using namespace X;
usingDirectiveDecl()
  matches using namespace X 

Matches any value declaration.

Example matches A, B, C and F
  enum X { A, B, C };
  void F();

Matches variable declarations.

Note: this does not match declarations of member variables, which are
"field" declarations in Clang parlance.

Example matches a
  int a;

Same as nestedNameSpecifier but matches NestedNameSpecifierLoc.

Matches nested name specifiers.

Given
  namespace ns {
    struct A { static void f(); };
    void A::f() {}
    void g() { A::f(); }
  }
  ns::A a;
nestedNameSpecifier()
  matches "ns::" and both "A::"

Matches QualTypes in the clang AST.

Matches array subscript expressions.

Given
  int i = a[1];
arraySubscriptExpr()
  matches "a[1]"

Matches asm statements.

 int i = 100;
  __asm("mov al, 2");
asmStmt()
  matches '__asm("mov al, 2")'

Matches binary operator expressions.

Example matches a || b
  !(a || b)

Matches break statements.

Given
  while (true) { break; }
breakStmt()
  matches 'break'

Matches a C-style cast expression.

Example: Matches (int*) 2.2f in
  int i = (int) 2.2f;

Matches call expressions.

Example matches x.y() and y()
  X x;
  x.y();
  y();

Matches case statements inside switch statements.

Given
  switch(a) { case 42: break; default: break; }
caseStmt()
  matches 'case 42: break;'.

Matches any cast nodes of Clang's AST.

Example: castExpr() matches each of the following:
  (int) 3;
  const_cast<Expr *>(SubExpr);
  char c = 0;
but does not match
  int i = (0);
  int k = 0;

Matches character literals (also matches wchar_t).

Not matching Hex-encoded chars (e.g. 0x1234, which is a IntegerLiteral),
though.

Example matches 'a', L'a'
  char ch = 'a'; wchar_t chw = L'a';

Matches compound (i.e. non-scalar) literals

Example match: {1}, (1, 2)
  int array[4] = {1}; vector int myvec = (vector int)(1, 2);

Matches compound statements.

Example matches '{}' and '{{}}'in 'for (;;) {{}}'
  for (;;) {{}}

Matches conditional operator expressions.

Example matches a ? b : c
  (a ? b : c) + 42

Matches continue statements.

Given
  while (true) { continue; }
continueStmt()
  matches 'continue'

Matches CUDA kernel call expression.

Example matches,
  kernel<<<i,j>>>();

Matches nodes where temporaries are created.

Example matches FunctionTakesString(GetStringByValue())
    (matcher = cxxBindTemporaryExpr())
  FunctionTakesString(GetStringByValue());
  FunctionTakesStringByPointer(GetStringPointer());

Matches bool literals.

Example matches true
  true

Matches catch statements.

  try {} catch(int i) {}
cxxCatchStmt()
  matches 'catch(int i)'

Matches a const_cast expression.

Example: Matches const_cast<int*>(&r) in
  int n = 42;
  const int &r(n);
  int* p = const_cast<int*>(&r);

Matches constructor call expressions (including implicit ones).

Example matches string(ptr, n) and ptr within arguments of f
    (matcher = cxxConstructExpr())
  void f(const string &a, const string &b);
  char *ptr;
  int n;
  f(string(ptr, n), ptr);

Matches the value of a default argument at the call site.

Example matches the CXXDefaultArgExpr placeholder inserted for the
    default value of the second parameter in the call expression f(42)
    (matcher = cxxDefaultArgExpr())
  void f(int x, int y = 0);
  f(42);

Matches delete expressions.

Given
  delete X;
cxxDeleteExpr()
  matches 'delete X'.

Matches a dynamic_cast expression.

Example:
  cxxDynamicCastExpr()
matches
  dynamic_cast<D*>(&b);
in
  struct B { virtual ~B() {} }; struct D : B {};
  B b;
  D* p = dynamic_cast<D*>(&b);

Matches range-based for statements.

cxxForRangeStmt() matches 'for (auto a : i)'
  int i[] =  {1, 2, 3}; for (auto a : i);
  for(int j = 0; j < 5; ++j);

Matches functional cast expressions

Example: Matches Foo(bar);
  Foo f = bar;
  Foo g = (Foo) bar;
  Foo h = Foo(bar);

Matches member call expressions.

Example matches x.y()
  X x;
  x.y();

Matches new expressions.

Given
  new X;
cxxNewExpr()
  matches 'new X'.

Matches nullptr literal.

Matches overloaded operator calls.

Note that if an operator isn't overloaded, it won't match. Instead, use
binaryOperator matcher.
Currently it does not match operators such as new delete.
FIXME: figure out why these do not match?

Example matches both operator<<((o << b), c) and operator<<(o, b)
    (matcher = cxxOperatorCallExpr())
  ostream &operator<< (ostream &out, int i) { };
  ostream &o; int b = 1, c = 1;
  o << b << c;

Matches a reinterpret_cast expression.

Either the source expression or the destination type can be matched
using has(), but hasDestinationType() is more specific and can be
more readable.

Example matches reinterpret_cast<char*>(&p) in
  void* p = reinterpret_cast<char*>(&p);

Matches a C++ static_cast expression.

See also: hasDestinationType
See also: reinterpretCast

Example:
  cxxStaticCastExpr()
matches
  static_cast<long>(8)
in
  long eight(static_cast<long>(8));

Matches functional cast expressions having N != 1 arguments

Example: Matches Foo(bar, bar)
  Foo h = Foo(bar, bar);

Matches implicit and explicit this expressions.

Example matches the implicit this expression in "return i".
    (matcher = cxxThisExpr())
struct foo {
  int i;
  int f() { return i; }
};

Matches throw expressions.

  try { throw 5; } catch(int i) {}
cxxThrowExpr()
  matches 'throw 5'

Matches try statements.

  try {} catch(int i) {}
cxxTryStmt()
  matches 'try {}'

Matches unresolved constructor call expressions.

Example matches T(t) in return statement of f
    (matcher = cxxUnresolvedConstructExpr())
  template <typename T>
  void f(const T& t) { return T(t); }

Matches expressions that refer to declarations.

Example matches x in if (x)
  bool x;
  if (x) {}

Matches declaration statements.

Given
  int a;
declStmt()
  matches 'int a'.

Matches default statements inside switch statements.

Given
  switch(a) { case 42: break; default: break; }
defaultStmt()
  matches 'default: break;'.

Matches do statements.

Given
  do {} while (true);
doStmt()
  matches 'do {} while(true)'

Matches explicit cast expressions.

Matches any cast expression written in user code, whether it be a
C-style cast, a functional-style cast, or a keyword cast.

Does not match implicit conversions.

Note: the name "explicitCast" is chosen to match Clang's terminology, as
Clang uses the term "cast" to apply to implicit conversions as well as to
actual cast expressions.

See also: hasDestinationType.

Example: matches all five of the casts in
  int((int)(reinterpret_cast<int>(static_cast<int>(const_cast<int>(42)))))
but does not match the implicit conversion in
  long ell = 42;

Matches expressions.

Example matches x()
  void f() { x(); }

Matches expressions that introduce cleanups to be run at the end
of the sub-expression's evaluation.

Example matches std::string()
  const std::string str = std::string();

Matches float literals of all sizes encodings, e.g.
1.0, 1.0f, 1.0L and 1e10.

Does not match implicit conversions such as
  float a = 10;

Matches for statements.

Example matches 'for (;;) {}'
  for (;;) {}
  int i[] =  {1, 2, 3}; for (auto a : i);

Matches GNU __null expression.

Matches goto statements.

Given
  goto FOO;
  FOO: bar();
gotoStmt()
  matches 'goto FOO'

Matches if statements.

Example matches 'if (x) {}'
  if (x) {}

Matches the implicit cast nodes of Clang's AST.

This matches many different places, including function call return value
eliding, as well as any type conversions.

Matches init list expressions.

Given
  int a[] = { 1, 2 };
  struct B { int x, y; };
  B b = { 5, 6 };
initListExpr()
  matches "{ 1, 2 }" and "{ 5, 6 }"

Matches integer literals of all sizes encodings, e.g.
1, 1L, 0x1 and 1U.

Does not match character-encoded integers such as L'a'.

Matches label statements.

Given
  goto FOO;
  FOO: bar();
labelStmt()
  matches 'FOO:'

Matches lambda expressions.

Example matches [&](){return 5;}
  [&](){return 5;}

Matches nodes where temporaries are materialized.

Example: Given
  struct T {void func()};
  T f();
  void g(T);
materializeTemporaryExpr() matches 'f()' in these statements
  T u(f());
  g(f());
but does not match
  f();
  f().func();

Matches member expressions.

Given
  class Y {
    void x() { this->x(); x(); Y y; y.x(); a; this->b; Y::b; }
    int a; static int b;
  };
memberExpr()
  matches this->x, x, y.x, a, this->b

Matches null statements.

  foo();;
nullStmt()
  matches the second ';'

Matches ObjectiveC Message invocation expressions.

The innermost message send invokes the "alloc" class method on the
NSString class, while the outermost message send invokes the
"initWithString" instance method on the object returned from
NSString's "alloc". This matcher should match both message sends.
  [[NSString alloc] initWithString:@"Hello"]

Matches parentheses used in expressions.

Example matches (foo() + 1)
  int foo() { return 1; }
  int a = (foo() + 1);

Matches return statements.

Given
  return 1;
returnStmt()
  matches 'return 1'

Matches statements.

Given
  { ++a; }
stmt()
  matches both the compound statement '{ ++a; }' and '++a'.

Matches string literals (also matches wide string literals).

Example matches "abcd", L"abcd"
  char *s = "abcd"; wchar_t *ws = L"abcd"

Matches substitutions of non-type template parameters.

Given
  template <int N>
  struct A { static const int n = N; };
  struct B : public A<42> {};
substNonTypeTemplateParmExpr()
  matches "N" in the right-hand side of "static const int n = N;"

Matches case and default statements inside switch statements.

Given
  switch(a) { case 42: break; default: break; }
switchCase()
  matches 'case 42: break;' and 'default: break;'.

Matches switch statements.

Given
  switch(a) { case 42: break; default: break; }
switchStmt()
  matches 'switch(a)'.

Matches sizeof (C99), alignof (C++11) and vec_step (OpenCL)

Given
  Foo x = bar;
  int y = sizeof(x) + alignof(x);
unaryExprOrTypeTraitExpr()
  matches sizeof(x) and alignof(x)

Matches unary operator expressions.

Example matches !a
  !a || b

Matches user defined literal operator call.

Example match: "foo"_suffix

Matches while statements.

Given
  while (true) {}
whileStmt()
  matches 'while (true) {}'.

Matches template arguments.

Given
  template <typename T> struct C {};
  C<int> c;
templateArgument()
  matches 'int' in C<int>.

Matches TypeLocs in the clang AST.

Matches all kinds of arrays.

Given
  int a[] = { 2, 3 };
  int b[4];
  void f() { int c[a[0]]; }
arrayType()
  matches "int a[]", "int b[4]" and "int c[a[0]]";

Matches atomic types.

Given
  _Atomic(int) i;
atomicType()
  matches "_Atomic(int) i"

Matches types nodes representing C++11 auto types.

Given:
  auto n = 4;
  int v[] = { 2, 3 }
  for (auto i : v) { }
autoType()
  matches "auto n" and "auto i"

Matches block pointer types, i.e. types syntactically represented as
"void (^)(int)".

The pointee is always required to be a FunctionType.

Matches builtin Types.

Given
  struct A {};
  A a;
  int b;
  float c;
  bool d;
builtinType()
  matches "int b", "float c" and "bool d"

Matches C99 complex types.

Given
  _Complex float f;
complexType()
  matches "_Complex float f"

Matches C arrays with a specified constant size.

Given
  void() {
    int a[2];
    int b[] = { 2, 3 };
    int c[b[0]];
  }
constantArrayType()
  matches "int a[2]"

Matches decayed type
Example matches i[] in declaration of f.
    (matcher = valueDecl(hasType(decayedType(hasDecayedType(pointerType())))))
Example matches i[1].
    (matcher = expr(hasType(decayedType(hasDecayedType(pointerType())))))
  void f(int i[]) {
    i[1] = 0;
  }

Matches C++ arrays whose size is a value-dependent expression.

Given
  template<typename T, int Size>
  class array {
    T data[Size];
  };
dependentSizedArrayType
  matches "T data[Size]"

Matches types specified with an elaborated type keyword or with a
qualified name.

Given
  namespace N {
    namespace M {
      class D {};
    }
  }
  class C {};

  class C c;
  N::M::D d;

elaboratedType() matches the type of the variable declarations of both
c and d.

Matches FunctionProtoType nodes.

Given
  int (*f)(int);
  void g();
functionProtoType()
  matches "int (*f)(int)" and the type of "g" in C++ mode.
  In C mode, "g" is not matched because it does not contain a prototype.

Matches FunctionType nodes.

Given
  int (*f)(int);
  void g();
functionType()
  matches "int (*f)(int)" and the type of "g".

Matches C arrays with unspecified size.

Given
  int a[] = { 2, 3 };
  int b[42];
  void f(int c[]) { int d[a[0]]; };
incompleteArrayType()
  matches "int a[]" and "int c[]"

Matches injected class name types.

Example matches S s, but not S<T> s.
    (matcher = parmVarDecl(hasType(injectedClassNameType())))
  template <typename T> struct S {
    void f(S s);
    void g(S<T> s);
  };

Matches lvalue reference types.

Given:
  int *a;
  int &b = *a;
  int &&c = 1;
  auto &d = b;
  auto &&e = c;
  auto &&f = 2;
  int g = 5;

lValueReferenceType() matches the types of b, d, and e. e is
matched since the type is deduced as int& by reference collapsing rules.

Matches member pointer types.
Given
  struct A { int i; }
  A::* ptr = A::i;
memberPointerType()
  matches "A::* ptr"

Matches an Objective-C object pointer type, which is different from
a pointer type, despite being syntactically similar.

Given
  int *a;

  @interface Foo
  @end
  Foo *f;
pointerType()
  matches "Foo *f", but does not match "int *a".

Matches ParenType nodes.

Given
  int (*ptr_to_array)[4];
  int *array_of_ptrs[4];

varDecl(hasType(pointsTo(parenType()))) matches ptr_to_array but not
array_of_ptrs.

Matches pointer types, but does not match Objective-C object pointer
types.

Given
  int *a;
  int &b = *a;
  int c = 5;

  @interface Foo
  @end
  Foo *f;
pointerType()
  matches "int *a", but does not match "Foo *f".

Matches rvalue reference types.

Given:
  int *a;
  int &b = *a;
  int &&c = 1;
  auto &d = b;
  auto &&e = c;
  auto &&f = 2;
  int g = 5;

rValueReferenceType() matches the types of c and f. e is not
matched as it is deduced to int& by reference collapsing rules.

Matches record types (e.g. structs, classes).

Given
  class C {};
  struct S {};

  C c;
  S s;

recordType() matches the type of the variable declarations of both c
and s.

Matches both lvalue and rvalue reference types.

Given
  int *a;
  int &b = *a;
  int &&c = 1;
  auto &d = b;
  auto &&e = c;
  auto &&f = 2;
  int g = 5;

referenceType() matches the types of b, c, d, e, and f.

Matches types that represent the result of substituting a type for a
template type parameter.

Given
  template <typename T>
  void F(T t) {
    int i = 1 + t;
  }

substTemplateTypeParmType() matches the type of 't' but not '1'

Matches template specialization types.

Given
  template <typename T>
  class C { };

  template class C<int>;  A
  C<char> var;            B

templateSpecializationType() matches the type of the explicit
instantiation in A and the type of the variable declaration in B.

Matches template type parameter types.

Example matches T, but not int.
    (matcher = templateTypeParmType())
  template <typename T> void f(int i);

Matches Types in the clang AST.

Matches typedef types.

Given
  typedef int X;
typedefType()
  matches "typedef int X"

Matches types nodes representing unary type transformations.

Given:
  typedef __underlying_type(T) type;
unaryTransformType()
  matches "__underlying_type(T)"

Matches C arrays with a specified size that is not an
integer-constant-expression.

Given
  void f() {
    int a[] = { 2, 3 }
    int b[42];
    int c[a[0]];
  }
variableArrayType()
  matches "int c[a[0]]"

Matches if all given matchers match.

Usable as: Any Matcher

Matches if any of the given matchers matches.

Usable as: Any Matcher

Matches any node.

Useful when another matcher requires a child matcher, but there's no
additional constraint. This will often be used with an explicit conversion
to an internal::Matcher<> type such as TypeMatcher.

Example: DeclarationMatcher(anything()) matches all declarations, e.g.,
"int* p" and "void f()" in
  int* p;
  void f();

Usable as: Any Matcher

Matches if the provided matcher does not match.

Example matches Y (matcher = cxxRecordDecl(unless(hasName("X"))))
  class X {};
  class Y {};

Usable as: Any Matcher

Matches the operator Name of operator expressions (binary or
unary).

Example matches a || b (matcher = binaryOperator(hasOperatorName("||")))
  !(a || b)

Matches literals that are equal to the given value.

Example matches true (matcher = cxxBoolLiteral(equals(true)))
  true

Usable as: Matcher<CharacterLiteral>, Matcher<CXXBoolLiteral>,
           Matcher<FloatingLiteral>, Matcher<IntegerLiteral>

Matches a C++ catch statement that has a catch-all handler.

Given
  try {
    ...
  } catch (int) {
    ...
  } catch (...) {
    ...
  }
endcode
cxxCatchStmt(isCatchAll()) matches catch(...) but not catch(int).

Checks that a call expression or a constructor call expression has
a specific number of arguments (including absent default arguments).

Example matches f(0, 0) (matcher = callExpr(argumentCountIs(2)))
  void f(int x, int y);
  f(0, 0);

Matches a constructor call expression which uses list initialization.

Matches constructor declarations that are copy constructors.

Given
  struct S {
    S(); #1
    S(const S &); #2
    S(S &&); #3
  };
cxxConstructorDecl(isCopyConstructor()) will match #2, but not #1 or #3.

Matches constructor declarations that are default constructors.

Given
  struct S {
    S(); #1
    S(const S &); #2
    S(S &&); #3
  };
cxxConstructorDecl(isDefaultConstructor()) will match #1, but not #2 or #3.

Matches constructor and conversion declarations that are marked with
the explicit keyword.

Given
  struct S {
    S(int); #1
    explicit S(double); #2
    operator int(); #3
    explicit operator bool(); #4
  };
cxxConstructorDecl(isExplicit()) will match #2, but not #1.
cxxConversionDecl(isExplicit()) will match #4, but not #3.

Matches constructor declarations that are move constructors.

Given
  struct S {
    S(); #1
    S(const S &); #2
    S(S &&); #3
  };
cxxConstructorDecl(isMoveConstructor()) will match #3, but not #1 or #2.

Matches constructor and conversion declarations that are marked with
the explicit keyword.

Given
  struct S {
    S(int); #1
    explicit S(double); #2
    operator int(); #3
    explicit operator bool(); #4
  };
cxxConstructorDecl(isExplicit()) will match #2, but not #1.
cxxConversionDecl(isExplicit()) will match #4, but not #3.

Matches a constructor initializer if it is initializing a base, as
opposed to a member.

Given
  struct B {};
  struct D : B {
    int I;
    D(int i) : I(i) {}
  };
  struct E : B {
    E() : B() {}
  };
cxxConstructorDecl(hasAnyConstructorInitializer(isBaseInitializer()))
  will match E(), but not match D(int).

Matches a constructor initializer if it is initializing a member, as
opposed to a base.

Given
  struct B {};
  struct D : B {
    int I;
    D(int i) : I(i) {}
  };
  struct E : B {
    E() : B() {}
  };
cxxConstructorDecl(hasAnyConstructorInitializer(isMemberInitializer()))
  will match D(int), but not match E().

Matches a constructor initializer if it is explicitly written in
code (as opposed to implicitly added by the compiler).

Given
  struct Foo {
    Foo() { }
    Foo(int) : foo_("A") { }
    string foo_;
  };
cxxConstructorDecl(hasAnyConstructorInitializer(isWritten()))
  will match Foo(int), but not Foo()

Matches if the given method declaration is const.

Given
struct A {
  void foo() const;
  void bar();
};

cxxMethodDecl(isConst()) matches A::foo() but not A::bar()

Matches if the given method declaration declares a copy assignment
operator.

Given
struct A {
  A &operator=(const A &);
  A &operator=(A &&);
};

cxxMethodDecl(isCopyAssignmentOperator()) matches the first method but not
the second one.

Matches if the given method or class declaration is final.

Given:
  class A final {};

  struct B {
    virtual void f();
  };

  struct C : B {
    void f() final;
  };
matches A and C::f, but not B, C, or B::f

Matches if the given method declaration declares a move assignment
operator.

Given
struct A {
  A &operator=(const A &);
  A &operator=(A &&);
};

cxxMethodDecl(isMoveAssignmentOperator()) matches the second method but not
the first one.

Matches if the given method declaration overrides another method.

Given
  class A {
   public:
    virtual void x();
  };
  class B : public A {
   public:
    virtual void x();
  };
  matches B::x

Matches if the given method declaration is pure.

Given
  class A {
   public:
    virtual void x() = 0;
  };
  matches A::x

Matches if the given method declaration is virtual.

Given
  class A {
   public:
    virtual void x();
  };
  matches A::x

Matches if the given method declaration has an explicit "virtual".

Given
  class A {
   public:
    virtual void x();
  };
  class B : public A {
   public:
    void x();
  };
  matches A::x but not B::x

Matches overloaded operator names.

Matches overloaded operator names specified in strings without the
"operator" prefix: e.g. "<<".

Given:
  class A { int operator*(); };
  const A &operator<<(const A &a, const A &b);
  A a;
  a << a;   <-- This matches

cxxOperatorCallExpr(hasOverloadedOperatorName("<<"))) matches the
specified line and
cxxRecordDecl(hasMethod(hasOverloadedOperatorName("*")))
matches the declaration of A.

Usable as: Matcher<CXXOperatorCallExpr>, Matcher<FunctionDecl>

Overloaded method as shortcut for isDerivedFrom(hasName(...)).

Matches explicit template specializations of function, class, or
static member variable template instantiations.

Given
  template<typename T> void A(T t) { }
  template<> void A(int N) { }
functionDecl(isExplicitTemplateSpecialization())
  matches the specialization A<int>().

Usable as: Matcher<FunctionDecl>, Matcher<VarDecl>, Matcher<CXXRecordDecl>

Matches if the given method or class declaration is final.

Given:
  class A final {};

  struct B {
    virtual void f();
  };

  struct C : B {
    void f() final;
  };
matches A and C::f, but not B, C, or B::f

Overloaded method as shortcut for
isSameOrDerivedFrom(hasName(...)).

Matches template instantiations of function, class, or static
member variable template instantiations.

Given
  template <typename T> class X {}; class A {}; X<A> x;
or
  template <typename T> class X {}; class A {}; template class X<A>;
cxxRecordDecl(hasName("::X"), isTemplateInstantiation())
  matches the template instantiation of X<A>.

But given
  template <typename T>  class X {}; class A {};
  template <> class X<A> {}; X<A> x;
cxxRecordDecl(hasName("::X"), isTemplateInstantiation())
  does not match, as X<A> is an explicit template specialization.

Usable as: Matcher<FunctionDecl>, Matcher<VarDecl>, Matcher<CXXRecordDecl>

Checks that a call expression or a constructor call expression has
a specific number of arguments (including absent default arguments).

Example matches f(0, 0) (matcher = callExpr(argumentCountIs(2)))
  void f(int x, int y);
  f(0, 0);

Matches literals that are equal to the given value.

Example matches true (matcher = cxxBoolLiteral(equals(true)))
  true

Usable as: Matcher<CharacterLiteral>, Matcher<CXXBoolLiteral>,
           Matcher<FloatingLiteral>, Matcher<IntegerLiteral>

Matches if the number of template arguments equals N.

Given
  template<typename T> struct C {};
  C<int> c;
classTemplateSpecializationDecl(templateArgumentCountIs(1))
  matches C<int>.

Checks that a compound statement contains a specific number of
child statements.

Example: Given
  { for (;;) {} }
compoundStmt(statementCountIs(0)))
  matches '{}'
  but does not match the outer compound statement.

Matches ConstantArrayType nodes that have the specified size.

Given
  int a[42];
  int b[2 * 21];
  int c[41], d[43];
constantArrayType(hasSize(42))
  matches "int a[42]" and "int b[2 * 21]"

Matches declaration statements that contain a specific number of
declarations.

Example: Given
  int a, b;
  int c;
  int d = 2, e;
declCountIs(2)
  matches 'int a, b;' and 'int d = 2, e;', but not 'int c;'.

Matches if a node equals a previously bound node.

Matches a node if it equals the node previously bound to ID.

Given
  class X { int a; int b; };
cxxRecordDecl(
    has(fieldDecl(hasName("a"), hasType(type().bind("t")))),
    has(fieldDecl(hasName("b"), hasType(type(equalsBoundNode("t"))))))
  matches the class X, as a and b have the same type.

Note that when multiple matches are involved via forEach* matchers,
equalsBoundNodes acts as a filter.
For example:
compoundStmt(
    forEachDescendant(varDecl().bind("d")),
    forEachDescendant(declRefExpr(to(decl(equalsBoundNode("d"))))))
will trigger a match for each combination of variable declaration
and reference to that variable declaration within a compound statement.

Matches declaration that has a given attribute.

Given
  __attribute__((device)) void f() { ... }
decl(hasAttr(clang::attr::CUDADevice)) matches the function declaration of
f. If the matcher is use from clang-query, attr::Kind parameter should be
passed as a quoted string. e.g., hasAttr("attr::CUDADevice").

Matches AST nodes that were expanded within files whose name is
partially matching a given regex.

Example matches Y but not X
    (matcher = cxxRecordDecl(isExpansionInFileMatching("AST.*"))
  #include "ASTMatcher.h"
  class X {};
ASTMatcher.h:
  class Y {};

Usable as: Matcher<Decl>, Matcher<Stmt>, Matcher<TypeLoc>

Matches AST nodes that were expanded within the main-file.

Example matches X but not Y
  (matcher = cxxRecordDecl(isExpansionInMainFile())
  #include <Y.h>
  class X {};
Y.h:
  class Y {};

Usable as: Matcher<Decl>, Matcher<Stmt>, Matcher<TypeLoc>

Matches AST nodes that were expanded within system-header-files.

Example matches Y but not X
    (matcher = cxxRecordDecl(isExpansionInSystemHeader())
  #include <SystemHeader.h>
  class X {};
SystemHeader.h:
  class Y {};

Usable as: Matcher<Decl>, Matcher<Stmt>, Matcher<TypeLoc>

Matches a declaration that has been implicitly added
by the compiler (eg. implicit defaultcopy constructors).

Matches private C++ declarations.

Given
  class C {
  public:    int a;
  protected: int b;
  private:   int c;
  };
fieldDecl(isPrivate())
  matches 'int c;' 

Matches protected C++ declarations.

Given
  class C {
  public:    int a;
  protected: int b;
  private:   int c;
  };
fieldDecl(isProtected())
  matches 'int b;' 

Matches public C++ declarations.

Given
  class C {
  public:    int a;
  protected: int b;
  private:   int c;
  };
fieldDecl(isPublic())
  matches 'int a;' 

Matches expressions that resolve to a null pointer constant, such as
GNU's __null, C++11's nullptr, or C's NULL macro.

Given:
  void *v1 = NULL;
  void *v2 = nullptr;
  void *v3 = __null; GNU extension
  char *cp = (char *)0;
  int *ip = 0;
  int i = 0;
expr(nullPointerConstant())
  matches the initializer for v1, v2, v3, cp, and ip. Does not match the
  initializer for i.

Matches literals that are equal to the given value.

Example matches true (matcher = cxxBoolLiteral(equals(true)))
  true

Usable as: Matcher<CharacterLiteral>, Matcher<CXXBoolLiteral>,
           Matcher<FloatingLiteral>, Matcher<IntegerLiteral>

Matches overloaded operator names.

Matches overloaded operator names specified in strings without the
"operator" prefix: e.g. "<<".

Given:
  class A { int operator*(); };
  const A &operator<<(const A &a, const A &b);
  A a;
  a << a;   <-- This matches

cxxOperatorCallExpr(hasOverloadedOperatorName("<<"))) matches the
specified line and
cxxRecordDecl(hasMethod(hasOverloadedOperatorName("*")))
matches the declaration of A.

Usable as: Matcher<CXXOperatorCallExpr>, Matcher<FunctionDecl>

Matches constexpr variable and function declarations.

Given:
  constexpr int foo = 42;
  constexpr int bar();
varDecl(isConstexpr())
  matches the declaration of foo.
functionDecl(isConstexpr())
  matches the declaration of bar.

Matches defaulted function declarations.

Given:
  class A { ~A(); };
  class B { ~B() = default; };
functionDecl(isDefaulted())
  matches the declaration of ~B, but not ~A.

Matches if a declaration has a body attached.

Example matches A, va, fa
  class A {};
  class B;  Doesn't match, as it has no body.
  int va;
  extern int vb;  Doesn't match, as it doesn't define the variable.
  void fa() {}
  void fb();  Doesn't match, as it has no body.

Usable as: Matcher<TagDecl>, Matcher<VarDecl>, Matcher<FunctionDecl>

Matches deleted function declarations.

Given:
  void Func();
  void DeletedFunc() = delete;
functionDecl(isDeleted())
  matches the declaration of DeletedFunc, but not Func.

Matches explicit template specializations of function, class, or
static member variable template instantiations.

Given
  template<typename T> void A(T t) { }
  template<> void A(int N) { }
functionDecl(isExplicitTemplateSpecialization())
  matches the specialization A<int>().

Usable as: Matcher<FunctionDecl>, Matcher<VarDecl>, Matcher<CXXRecordDecl>

Matches extern "C" function declarations.

Given:
  extern "C" void f() {}
  extern "C" { void g() {} }
  void h() {}
functionDecl(isExternC())
  matches the declaration of f and g, but not the declaration h

Matches function and namespace declarations that are marked with
the inline keyword.

Given
  inline void f();
  void g();
  namespace n {
  inline namespace m {}
  }
functionDecl(isInline()) will match ::f().
namespaceDecl(isInline()) will match n::m.

Matches functions that have a non-throwing exception specification.

Given:
  void f();
  void g() noexcept;
  void h() throw();
  void i() throw(int);
  void j() noexcept(false);
functionDecl(isNoThrow())
  matches the declarations of g, and h, but not f, i or j.

Matches template instantiations of function, class, or static
member variable template instantiations.

Given
  template <typename T> class X {}; class A {}; X<A> x;
or
  template <typename T> class X {}; class A {}; template class X<A>;
cxxRecordDecl(hasName("::X"), isTemplateInstantiation())
  matches the template instantiation of X<A>.

But given
  template <typename T>  class X {}; class A {};
  template <> class X<A> {}; X<A> x;
cxxRecordDecl(hasName("::X"), isTemplateInstantiation())
  does not match, as X<A> is an explicit template specialization.

Usable as: Matcher<FunctionDecl>, Matcher<VarDecl>, Matcher<CXXRecordDecl>

Matches if a function declaration is variadic.

Example matches f, but not g or h. The function i will not match, even when
compiled in C mode.
  void f(...);
  void g(int);
  template <typename... Ts> void h(Ts...);
  void i();

Matches FunctionDecls and FunctionProtoTypes that have a
specific parameter count.

Given
  void f(int i) {}
  void g(int i, int j) {}
  void h(int i, int j);
  void j(int i);
  void k(int x, int y, int z, ...);
functionDecl(parameterCountIs(2))
  matches void g(int i, int j) {}
functionProtoType(parameterCountIs(2))
  matches void h(int i, int j)
functionProtoType(parameterCountIs(3))
  matches void k(int x, int y, int z, ...);

Matches FunctionDecls and FunctionProtoTypes that have a
specific parameter count.

Given
  void f(int i) {}
  void g(int i, int j) {}
  void h(int i, int j);
  void j(int i);
  void k(int x, int y, int z, ...);
functionDecl(parameterCountIs(2))
  matches void g(int i, int j) {}
functionProtoType(parameterCountIs(2))
  matches void h(int i, int j)
functionProtoType(parameterCountIs(3))
  matches void k(int x, int y, int z, ...);

Matches literals that are equal to the given value.

Example matches true (matcher = cxxBoolLiteral(equals(true)))
  true

Usable as: Matcher<CharacterLiteral>, Matcher<CXXBoolLiteral>,
           Matcher<FloatingLiteral>, Matcher<IntegerLiteral>

Matches member expressions that are called with '->' as opposed
to '.'.

Member calls on the implicit this pointer match as called with '->'.

Given
  class Y {
    void x() { this->x(); x(); Y y; y.x(); a; this->b; Y::b; }
    int a;
    static int b;
  };
memberExpr(isArrow())
  matches this->x, x, y.x, a, this->b

Matches NamedDecl nodes that have the specified name.

Supports specifying enclosing namespaces or classes by prefixing the name
with '<enclosing>::'.
Does not match typedefs of an underlying type with the given name.

Example matches X (Name == "X")
  class X;

Example matches X (Name is one of "::a::b::X", "a::b::X", "b::X", "X")
  namespace a { namespace b { class X; } }

Matches NamedDecl nodes whose fully qualified names contain
a substring matched by the given RegExp.

Supports specifying enclosing namespaces or classes by
prefixing the name with '<enclosing>::'.  Does not match typedefs
of an underlying type with the given name.

Example matches X (regexp == "::X")
  class X;

Example matches X (regexp is one of "::X", "^foo::.*X", among others)
  namespace foo { namespace bar { class X; } }

Matches anonymous namespace declarations.

Given
  namespace n {
  namespace {} #1
  }
namespaceDecl(isAnonymous()) will match #1 but not ::n.

Matches function and namespace declarations that are marked with
the inline keyword.

Given
  inline void f();
  void g();
  namespace n {
  inline namespace m {}
  }
functionDecl(isInline()) will match ::f().
namespaceDecl(isInline()) will match n::m.

Checks that a call expression or a constructor call expression has
a specific number of arguments (including absent default arguments).

Example matches f(0, 0) (matcher = callExpr(argumentCountIs(2)))
  void f(int x, int y);
  f(0, 0);

Matches when the selector is a keyword selector

objCMessageExpr(hasKeywordSelector()) matches the generated setFrame
message expression in

  UIWebView *webView = ...;
  CGRect bodyFrame = webView.frame;
  bodyFrame.size.height = self.bodyContentHeight;
  webView.frame = bodyFrame;
      ^---- matches here

Matches when the selector is the empty selector

Matches only when the selector of the objCMessageExpr is NULL. This may
represent an error condition in the tree!

Matches when BaseName == Selector.getAsString()

 matcher = objCMessageExpr(hasSelector("loadHTMLString:baseURL:"));
 matches the outer message expr in the code below, but NOT the message
 invocation for self.bodyView.
    [self.bodyView loadHTMLString:html baseURL:NULL];

Matches when the selector is a Unary Selector

 matcher = objCMessageExpr(matchesSelector(hasUnarySelector());
 matches self.bodyView in the code below, but NOT the outer message
 invocation of "loadHTMLString:baseURL:".
    [self.bodyView loadHTMLString:html baseURL:NULL];

Matches ObjC selectors whose name contains
a substring matched by the given RegExp.
 matcher = objCMessageExpr(matchesSelector("loadHTMLStringmatches the outer message expr in the code below, but NOT the message
 invocation for self.bodyView.
    [self.bodyView loadHTMLString:html baseURL:NULL];

Matches when the selector has the specified number of arguments

 matcher = objCMessageExpr(numSelectorArgs(0));
 matches self.bodyView in the code below

 matcher = objCMessageExpr(numSelectorArgs(2));
 matches the invocation of "loadHTMLString:baseURL:" but not that
 of self.bodyView
    [self.bodyView loadHTMLString:html baseURL:NULL];

Matches if the matched type is represented by the given string.

Given
  class Y { public: void x(); };
  void z() { Y* y; y->x(); }
cxxMemberCallExpr(on(hasType(asString("class Y *"))))
  matches y->x()

Matches if a node equals a previously bound node.

Matches a node if it equals the node previously bound to ID.

Given
  class X { int a; int b; };
cxxRecordDecl(
    has(fieldDecl(hasName("a"), hasType(type().bind("t")))),
    has(fieldDecl(hasName("b"), hasType(type(equalsBoundNode("t"))))))
  matches the class X, as a and b have the same type.

Note that when multiple matches are involved via forEach* matchers,
equalsBoundNodes acts as a filter.
For example:
compoundStmt(
    forEachDescendant(varDecl().bind("d")),
    forEachDescendant(declRefExpr(to(decl(equalsBoundNode("d"))))))
will trigger a match for each combination of variable declaration
and reference to that variable declaration within a compound statement.

Matches QualType nodes that have local CV-qualifiers attached to
the node, not hidden within a typedef.

Given
  typedef const int const_int;
  const_int i;
  int *const j;
  int *volatile k;
  int m;
varDecl(hasType(hasLocalQualifiers())) matches only j and k.
i is const-qualified but the qualifier is not local.

Matches QualType nodes that are of character type.

Given
  void a(char);
  void b(wchar_t);
  void c(double);
functionDecl(hasAnyParameter(hasType(isAnyCharacter())))
matches "a(char)", "b(wchar_t)", but not "c(double)".

Matches QualType nodes that are const-qualified, i.e., that
include "top-level" const.

Given
  void a(int);
  void b(int const);
  void c(const int);
  void d(const int*);
  void e(int const) {};
functionDecl(hasAnyParameter(hasType(isConstQualified())))
  matches "void b(int const)", "void c(const int)" and
  "void e(int const) {}". It does not match d as there
  is no top-level const on the parameter type "const int *".

Matches QualType nodes that are of integer type.

Given
  void a(int);
  void b(long);
  void c(double);
functionDecl(hasAnyParameter(hasType(isInteger())))
matches "a(int)", "b(long)", but not "c(double)".

Matches QualType nodes that are volatile-qualified, i.e., that
include "top-level" volatile.

Given
  void a(int);
  void b(int volatile);
  void c(volatile int);
  void d(volatile int*);
  void e(int volatile) {};
functionDecl(hasAnyParameter(hasType(isVolatileQualified())))
  matches "void b(int volatile)", "void c(volatile int)" and
  "void e(int volatile) {}". It does not match d as there
  is no top-level volatile on the parameter type "volatile int *".

Matches RecordDecl object that are spelled with "class."

Example matches C, but not S or U.
  struct S {};
  class C {};
  union U {};

Matches RecordDecl object that are spelled with "struct."

Example matches S, but not C or U.
  struct S {};
  class C {};
  union U {};

Matches RecordDecl object that are spelled with "union."

Example matches U, but not C or S.
  struct S {};
  class C {};
  union U {};

Matches if a node equals a previously bound node.

Matches a node if it equals the node previously bound to ID.

Given
  class X { int a; int b; };
cxxRecordDecl(
    has(fieldDecl(hasName("a"), hasType(type().bind("t")))),
    has(fieldDecl(hasName("b"), hasType(type(equalsBoundNode("t"))))))
  matches the class X, as a and b have the same type.

Note that when multiple matches are involved via forEach* matchers,
equalsBoundNodes acts as a filter.
For example:
compoundStmt(
    forEachDescendant(varDecl().bind("d")),
    forEachDescendant(declRefExpr(to(decl(equalsBoundNode("d"))))))
will trigger a match for each combination of variable declaration
and reference to that variable declaration within a compound statement.

Matches AST nodes that were expanded within files whose name is
partially matching a given regex.

Example matches Y but not X
    (matcher = cxxRecordDecl(isExpansionInFileMatching("AST.*"))
  #include "ASTMatcher.h"
  class X {};
ASTMatcher.h:
  class Y {};

Usable as: Matcher<Decl>, Matcher<Stmt>, Matcher<TypeLoc>

Matches AST nodes that were expanded within the main-file.

Example matches X but not Y
  (matcher = cxxRecordDecl(isExpansionInMainFile())
  #include <Y.h>
  class X {};
Y.h:
  class Y {};

Usable as: Matcher<Decl>, Matcher<Stmt>, Matcher<TypeLoc>

Matches AST nodes that were expanded within system-header-files.

Example matches Y but not X
    (matcher = cxxRecordDecl(isExpansionInSystemHeader())
  #include <SystemHeader.h>
  class X {};
SystemHeader.h:
  class Y {};

Usable as: Matcher<Decl>, Matcher<Stmt>, Matcher<TypeLoc>

Matches if a declaration has a body attached.

Example matches A, va, fa
  class A {};
  class B;  Doesn't match, as it has no body.
  int va;
  extern int vb;  Doesn't match, as it doesn't define the variable.
  void fa() {}
  void fb();  Doesn't match, as it has no body.

Usable as: Matcher<TagDecl>, Matcher<VarDecl>, Matcher<FunctionDecl>

Matches a TemplateArgument of integral type with a given value.

Note that 'Value' is a string as the template argument's value is
an arbitrary precision integer. 'Value' must be euqal to the canonical
representation of that integral value in base 10.

Given
  template<int T> struct A {};
  C<42> c;
classTemplateSpecializationDecl(
  hasAnyTemplateArgument(equalsIntegralValue("42")))
  matches the implicit instantiation of C in C<42>.

Matches a TemplateArgument that is an integral value.

Given
  template<int T> struct A {};
  C<42> c;
classTemplateSpecializationDecl(
  hasAnyTemplateArgument(isIntegral()))
  matches the implicit instantiation of C in C<42>
  with isIntegral() matching 42.

Matches if the number of template arguments equals N.

Given
  template<typename T> struct C {};
  C<int> c;
classTemplateSpecializationDecl(templateArgumentCountIs(1))
  matches C<int>.

Matches AST nodes that were expanded within files whose name is
partially matching a given regex.

Example matches Y but not X
    (matcher = cxxRecordDecl(isExpansionInFileMatching("AST.*"))
  #include "ASTMatcher.h"
  class X {};
ASTMatcher.h:
  class Y {};

Usable as: Matcher<Decl>, Matcher<Stmt>, Matcher<TypeLoc>

Matches AST nodes that were expanded within the main-file.

Example matches X but not Y
  (matcher = cxxRecordDecl(isExpansionInMainFile())
  #include <Y.h>
  class X {};
Y.h:
  class Y {};

Usable as: Matcher<Decl>, Matcher<Stmt>, Matcher<TypeLoc>

Matches AST nodes that were expanded within system-header-files.

Example matches Y but not X
    (matcher = cxxRecordDecl(isExpansionInSystemHeader())
  #include <SystemHeader.h>
  class X {};
SystemHeader.h:
  class Y {};

Usable as: Matcher<Decl>, Matcher<Stmt>, Matcher<TypeLoc>

Matches type bool.

Given
 struct S { bool func(); };
functionDecl(returns(booleanType()))
  matches "bool func();"

Matches if a node equals a previously bound node.

Matches a node if it equals the node previously bound to ID.

Given
  class X { int a; int b; };
cxxRecordDecl(
    has(fieldDecl(hasName("a"), hasType(type().bind("t")))),
    has(fieldDecl(hasName("b"), hasType(type(equalsBoundNode("t"))))))
  matches the class X, as a and b have the same type.

Note that when multiple matches are involved via forEach* matchers,
equalsBoundNodes acts as a filter.
For example:
compoundStmt(
    forEachDescendant(varDecl().bind("d")),
    forEachDescendant(declRefExpr(to(decl(equalsBoundNode("d"))))))
will trigger a match for each combination of variable declaration
and reference to that variable declaration within a compound statement.

Matches type void.

Given
 struct S { void func(); };
functionDecl(returns(voidType()))
  matches "void func();"

Matches unary expressions of a certain kind.

Given
  int x;
  int s = sizeof(x) + alignof(x)
unaryExprOrTypeTraitExpr(ofKind(UETT_SizeOf))
  matches sizeof(x)

Matches the operator Name of operator expressions (binary or
unary).

Example matches a || b (matcher = binaryOperator(hasOperatorName("||")))
  !(a || b)

Matches a variable declaration that has automatic storage duration.

Example matches x, but not y, z, or a.
(matcher = varDecl(hasAutomaticStorageDuration())
void f() {
  int x;
  static int y;
  thread_local int z;
}
int a;

Matches a variable declaration that does not have local storage.

Example matches y and z (matcher = varDecl(hasGlobalStorage())
void f() {
  int x;
  static int y;
}
int z;

Matches a variable declaration that has function scope and is a
non-static local variable.

Example matches x (matcher = varDecl(hasLocalStorage())
void f() {
  int x;
  static int y;
}
int z;

Matches a variable declaration that has static storage duration.

Example matches y and a, but not x or z.
(matcher = varDecl(hasStaticStorageDuration())
void f() {
  int x;
  static int y;
  thread_local int z;
}
int a;

Matches a variable declaration that has thread storage duration.

Example matches z, but not x, z, or a.
(matcher = varDecl(hasThreadStorageDuration())
void f() {
  int x;
  static int y;
  thread_local int z;
}
int a;

Matches constexpr variable and function declarations.

Given:
  constexpr int foo = 42;
  constexpr int bar();
varDecl(isConstexpr())
  matches the declaration of foo.
functionDecl(isConstexpr())
  matches the declaration of bar.

Matches if a declaration has a body attached.

Example matches A, va, fa
  class A {};
  class B;  Doesn't match, as it has no body.
  int va;
  extern int vb;  Doesn't match, as it doesn't define the variable.
  void fa() {}
  void fb();  Doesn't match, as it has no body.

Usable as: Matcher<TagDecl>, Matcher<VarDecl>, Matcher<FunctionDecl>

Matches a variable declaration that is an exception variable from
a C++ catch block, or an Objective-C statement.

Example matches x (matcher = varDecl(isExceptionVariable())
void f(int y) {
  try {
  } catch (int x) {
  }
}

Matches explicit template specializations of function, class, or
static member variable template instantiations.

Given
  template<typename T> void A(T t) { }
  template<> void A(int N) { }
functionDecl(isExplicitTemplateSpecialization())
  matches the specialization A<int>().

Usable as: Matcher<FunctionDecl>, Matcher<VarDecl>, Matcher<CXXRecordDecl>

Matches template instantiations of function, class, or static
member variable template instantiations.

Given
  template <typename T> class X {}; class A {}; X<A> x;
or
  template <typename T> class X {}; class A {}; template class X<A>;
cxxRecordDecl(hasName("::X"), isTemplateInstantiation())
  matches the template instantiation of X<A>.

But given
  template <typename T>  class X {}; class A {};
  template <> class X<A> {}; X<A> x;
cxxRecordDecl(hasName("::X"), isTemplateInstantiation())
  does not match, as X<A> is an explicit template specialization.

Usable as: Matcher<FunctionDecl>, Matcher<VarDecl>, Matcher<CXXRecordDecl>

Matches declarations that are template instantiations or are inside
template instantiations.

Given
  template<typename T> void A(T t) { T i; }
  A(0);
  A(0U);
functionDecl(isInstantiated())
  matches 'A(int) {...};' and 'A(unsigned) {...}'.

Matches statements inside of a template instantiation.

Given
  int j;
  template<typename T> void A(T t) { T i; j += 42;}
  A(0);
  A(0U);
declStmt(isInTemplateInstantiation())
  matches 'int i;' and 'unsigned i'.
unless(stmt(isInTemplateInstantiation()))
  will NOT match j += 42; as it's shared between the template definition and
  instantiation.

Matches if any of the given matchers matches.

Unlike anyOf, eachOf will generate a match result for each
matching submatcher.

For example, in:
  class A { int a; int b; };
The matcher:
  cxxRecordDecl(eachOf(has(fieldDecl(hasName("a")).bind("v")),
                       has(fieldDecl(hasName("b")).bind("v"))))
will generate two results binding "v", the first of which binds
the field declaration of a, the second the field declaration of
b.

Usable as: Any Matcher

Matches AST nodes that have descendant AST nodes that match the
provided matcher.

Example matches X, A, B, C
  (matcher = cxxRecordDecl(forEachDescendant(cxxRecordDecl(hasName("X")))))
  class X {};  Matches X, because X::X is a class of name X inside X.
  class A { class X {}; };
  class B { class C { class X {}; }; };

DescendantT must be an AST base type.

As opposed to 'hasDescendant', 'forEachDescendant' will cause a match for
each result that matches instead of only on the first one.

Note: Recursively combined ForEachDescendant can cause many matches:
  cxxRecordDecl(forEachDescendant(cxxRecordDecl(
    forEachDescendant(cxxRecordDecl())
  )))
will match 10 times (plus injected class name matches) on:
  class A { class B { class C { class D { class E {}; }; }; }; };

Usable as: Any Matcher

Matches AST nodes that have child AST nodes that match the
provided matcher.

Example matches X, Y
  (matcher = cxxRecordDecl(forEach(cxxRecordDecl(hasName("X")))
  class X {};  Matches X, because X::X is a class of name X inside X.
  class Y { class X {}; };
  class Z { class Y { class X {}; }; };  Does not match Z.

ChildT must be an AST base type.

As opposed to 'has', 'forEach' will cause a match for each result that
matches instead of only on the first one.

Usable as: Any Matcher

Matches AST nodes that have an ancestor that matches the provided
matcher.

Given
void f() { if (true) { int x = 42; } }
void g() { for (;;) { int x = 43; } }
expr(integerLiteral(hasAncestor(ifStmt()))) matches 42, but not 43.

Usable as: Any Matcher

Matches AST nodes that have descendant AST nodes that match the
provided matcher.

Example matches X, Y, Z
    (matcher = cxxRecordDecl(hasDescendant(cxxRecordDecl(hasName("X")))))
  class X {};  Matches X, because X::X is a class of name X inside X.
  class Y { class X {}; };
  class Z { class Y { class X {}; }; };

DescendantT must be an AST base type.

Usable as: Any Matcher

Matches AST nodes that have child AST nodes that match the
provided matcher.

Example matches X, Y
  (matcher = cxxRecordDecl(has(cxxRecordDecl(hasName("X")))
  class X {};  Matches X, because X::X is a class of name X inside X.
  class Y { class X {}; };
  class Z { class Y { class X {}; }; };  Does not match Z.

ChildT must be an AST base type.

Usable as: Any Matcher

Matches AST nodes that have a parent that matches the provided
matcher.

Given
void f() { for (;;) { int x = 42; if (true) { int x = 43; } } }
compoundStmt(hasParent(ifStmt())) matches "{ int x = 43; }".

Usable as: Any Matcher

Matches the base expression of an array subscript expression.

Given
  int i[5];
  void f() { i[1] = 42; }
arraySubscriptExpression(hasBase(implicitCastExpr(
    hasSourceExpression(declRefExpr()))))
  matches i[1] with the declRefExpr() matching i

Matches the index expression of an array subscript expression.

Given
  int i[5];
  void f() { i[1] = 42; }
arraySubscriptExpression(hasIndex(integerLiteral()))
  matches i[1] with the integerLiteral() matching 1

Matches the left hand side of binary operator expressions.

Example matches a (matcher = binaryOperator(hasLHS()))
  a || b

Matches the right hand side of binary operator expressions.

Example matches b (matcher = binaryOperator(hasRHS()))
  a || b

Matches arrays and C99 complex types that have a specific element
type.

Given
  struct A {};
  A a[7];
  int b[7];
arrayType(hasElementType(builtinType()))
  matches "int b[7]"

Usable as: Matcher<ArrayType>, Matcher<ComplexType>

Matches arrays and C99 complex types that have a specific element
type.

Given
  struct A {};
  A a[7];
  int b[7];
arrayType(hasElementType(builtinType()))
  matches "int b[7]"

Usable as: Matcher<ArrayType>, Matcher<ComplexType>

Matches atomic types with a specific value type.

Given
  _Atomic(int) i;
  _Atomic(float) f;
atomicType(hasValueType(isInteger()))
 matches "_Atomic(int) i"

Usable as: Matcher<AtomicType>

Matches atomic types with a specific value type.

Given
  _Atomic(int) i;
  _Atomic(float) f;
atomicType(hasValueType(isInteger()))
 matches "_Atomic(int) i"

Usable as: Matcher<AtomicType>

Matches AutoType nodes where the deduced type is a specific type.

Note: There is no TypeLoc for the deduced type and thus no
getDeducedLoc() matcher.

Given
  auto a = 1;
  auto b = 2.0;
autoType(hasDeducedType(isInteger()))
  matches "auto a"

Usable as: Matcher<AutoType>

Matches if either the left hand side or the right hand side of a
binary operator matches.

Matches the left hand side of binary operator expressions.

Example matches a (matcher = binaryOperator(hasLHS()))
  a || b

Matches the right hand side of binary operator expressions.

Example matches b (matcher = binaryOperator(hasRHS()))
  a || b

Narrows PointerType (and similar) matchers to those where the
pointee matches a given matcher.

Given
  int *a;
  int const *b;
  float const *f;
pointerType(pointee(isConstQualified(), isInteger()))
  matches "int const *b"

Usable as: Matcher<BlockPointerType>, Matcher<MemberPointerType>,
  Matcher<PointerType>, Matcher<ReferenceType>

Narrows PointerType (and similar) matchers to those where the
pointee matches a given matcher.

Given
  int *a;
  int const *b;
  float const *f;
pointerType(pointee(isConstQualified(), isInteger()))
  matches "int const *b"

Usable as: Matcher<BlockPointerType>, Matcher<MemberPointerType>,
  Matcher<PointerType>, Matcher<ReferenceType>

Matches all arguments and their respective ParmVarDecl.

Given
  void f(int i);
  int y;
  f(y);
callExpr(declRefExpr(to(varDecl(hasName("y")))),
parmVarDecl(hasType(isInteger())))
  matches f(y);
with declRefExpr(...)
  matching int y
and parmVarDecl(...)
  matching int i

Matches any argument of a call expression or a constructor call
expression.

Given
  void x(int, int, int) { int y; x(1, y, 42); }
callExpr(hasAnyArgument(declRefExpr()))
  matches x(1, y, 42)
with hasAnyArgument(...)
  matching y

FIXME: Currently this will ignore parentheses and implicit casts on
the argument before applying the inner matcher. We'll want to remove
this to allow for greater control by the user once ignoreImplicit()
has been implemented.

Matches the n'th argument of a call expression or a constructor
call expression.

Example matches y in x(y)
    (matcher = callExpr(hasArgument(0, declRefExpr())))
  void x(int) { int y; x(y); }

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches each constructor initializer in a constructor definition.

Given
  class A { A() : i(42), j(42) {} int i; int j; };
cxxConstructorDecl(forEachConstructorInitializer(
  forField(decl().bind("x"))
))
  will trigger two matches, binding for 'i' and 'j' respectively.

Matches a constructor initializer.

Given
  struct Foo {
    Foo() : foo_(1) { }
    int foo_;
  };
cxxRecordDecl(has(cxxConstructorDecl(
  hasAnyConstructorInitializer(anything())
)))
  record matches Foo, hasAnyConstructorInitializer matches foo_(1)

Matches the field declaration of a constructor initializer.

Given
  struct Foo {
    Foo() : foo_(1) { }
    int foo_;
  };
cxxRecordDecl(has(cxxConstructorDecl(hasAnyConstructorInitializer(
    forField(hasName("foo_"))))))
  matches Foo
with forField matching foo_

Matches the initializer expression of a constructor initializer.

Given
  struct Foo {
    Foo() : foo_(1) { }
    int foo_;
  };
cxxRecordDecl(has(cxxConstructorDecl(hasAnyConstructorInitializer(
    withInitializer(integerLiteral(equals(1)))))))
  matches Foo
with withInitializer matching (1)

Matches a 'for', 'while', 'do while' statement or a function
definition that has a given body.

Given
  for (;;) {}
hasBody(compoundStmt())
  matches 'for (;;) {}'
with compoundStmt()
  matching '{}'

Matches the initialization statement of a for loop.

Example:
    forStmt(hasLoopVariable(anything()))
matches 'int x' in
    for (int x : a) { }

Matches the range initialization statement of a for loop.

Example:
    forStmt(hasRangeInit(anything()))
matches 'a' in
    for (int x : a) { }

Matches on the implicit object argument of a member call expression.

Example matches y.x()
  (matcher = cxxMemberCallExpr(on(hasType(cxxRecordDecl(hasName("Y"))))))
  class Y { public: void x(); };
  void z() { Y y; y.x(); }",

FIXME: Overload to allow directly matching types?

Overloaded to match the type's declaration.

Matches if the expression's type either matches the specified
matcher, or is a pointer to a type that matches the InnerMatcher.

Matches the class declaration that the given method declaration
belongs to.

FIXME: Generalize this for other kinds of declarations.
FIXME: What other kind of declarations would we need to generalize
this to?

Example matches A() in the last line
    (matcher = cxxConstructExpr(hasDeclaration(cxxMethodDecl(
        ofClass(hasName("A"))))))
  class A {
   public:
    A();
  };
  A a = A();

Matches the first method of a class or struct that satisfies InnerMatcher.

Given:
  class A { void func(); };
  class B { void member(); };

cxxRecordDecl(hasMethod(hasName("func"))) matches the declaration of
A but not B.

Matches C++ classes that are directly or indirectly derived from
a class matching Base.

Note that a class is not considered to be derived from itself.

Example matches Y, Z, C (Base == hasName("X"))
  class X;
  class Y : public X {};  directly derived
  class Z : public Y {};  indirectly derived
  typedef X A;
  typedef A B;
  class C : public B {};  derived from a typedef of X

In the following example, Bar matches isDerivedFrom(hasName("X")):
  class Foo;
  typedef Foo X;
  class Bar : public Foo {};  derived from a type that X is a typedef of

Similar to isDerivedFrom(), but also matches classes that directly
match Base.

Matches if the call expression's callee's declaration matches the
given matcher.

Example matches y.x() (matcher = callExpr(callee(
                                   cxxMethodDecl(hasName("x")))))
  class Y { public: void x(); };
  void z() { Y y; y.x(); }

Matches if the call expression's callee expression matches.

Given
  class Y { void x() { this->x(); x(); Y y; y.x(); } };
  void f() { f(); }
callExpr(callee(expr()))
  matches this->x(), x(), y.x(), f()
with callee(...)
  matching this->x, x, y.x, f respectively

Note: Callee cannot take the more general internal::Matcher<Expr>
because this introduces ambiguous overloads with calls to Callee taking a
internal::Matcher<Decl>, as the matcher hierarchy is purely
implemented in terms of implicit casts.

Matches all arguments and their respective ParmVarDecl.

Given
  void f(int i);
  int y;
  f(y);
callExpr(declRefExpr(to(varDecl(hasName("y")))),
parmVarDecl(hasType(isInteger())))
  matches f(y);
with declRefExpr(...)
  matching int y
and parmVarDecl(...)
  matching int i

Matches any argument of a call expression or a constructor call
expression.

Given
  void x(int, int, int) { int y; x(1, y, 42); }
callExpr(hasAnyArgument(declRefExpr()))
  matches x(1, y, 42)
with hasAnyArgument(...)
  matching y

FIXME: Currently this will ignore parentheses and implicit casts on
the argument before applying the inner matcher. We'll want to remove
this to allow for greater control by the user once ignoreImplicit()
has been implemented.

Matches the n'th argument of a call expression or a constructor
call expression.

Example matches y in x(y)
    (matcher = callExpr(hasArgument(0, declRefExpr())))
  void x(int) { int y; x(y); }

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

If the given case statement does not use the GNU case range
extension, matches the constant given in the statement.

Given
  switch (1) { case 1: case 1+1: case 3 ... 4: ; }
caseStmt(hasCaseConstant(integerLiteral()))
  matches "case 1:"

Matches if the cast's source expression matches the given matcher.

Example: matches "a string" (matcher =
                                 hasSourceExpression(cxxConstructExpr()))
class URL { URL(string); };
URL url = "a string";

Matches classTemplateSpecializations that have at least one
TemplateArgument matching the given InnerMatcher.

Given
  template<typename T> class A {};
  template<> class A<double> {};
  A<int> a;
classTemplateSpecializationDecl(hasAnyTemplateArgument(
    refersToType(asString("int"))))
  matches the specialization A<int>

Matches classTemplateSpecializations where the n'th TemplateArgument
matches the given InnerMatcher.

Given
  template<typename T, typename U> class A {};
  A<bool, int> b;
  A<int, bool> c;
classTemplateSpecializationDecl(hasTemplateArgument(
    1, refersToType(asString("int"))))
  matches the specialization A<bool, int>

Matches arrays and C99 complex types that have a specific element
type.

Given
  struct A {};
  A a[7];
  int b[7];
arrayType(hasElementType(builtinType()))
  matches "int b[7]"

Usable as: Matcher<ArrayType>, Matcher<ComplexType>

Matches arrays and C99 complex types that have a specific element
type.

Given
  struct A {};
  A a[7];
  int b[7];
arrayType(hasElementType(builtinType()))
  matches "int b[7]"

Usable as: Matcher<ArrayType>, Matcher<ComplexType>

Matches compound statements where at least one substatement matches
a given matcher.

Given
  { {}; 1+2; }
hasAnySubstatement(compoundStmt())
  matches '{ {}; 1+2; }'
with compoundStmt()
  matching '{}'

Matches the condition expression of an if statement, for loop,
or conditional operator.

Example matches true (matcher = hasCondition(cxxBoolLiteral(equals(true))))
  if (true) {}

Matches the false branch expression of a conditional operator.

Example matches b
  condition ? a : b

Matches the true branch expression of a conditional operator.

Example matches a
  condition ? a : b

Matches the decayed type, whos decayed type matches InnerMatcher

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches a DeclRefExpr that refers to a declaration through a
specific using shadow declaration.

Given
  namespace a { void f() {} }
  using a::f;
  void g() {
    f();     Matches this ..
    a::f();  .. but not this.
  }
declRefExpr(throughUsingDecl(anything()))
  matches f()

Matches a DeclRefExpr that refers to a declaration that matches the
specified matcher.

Example matches x in if(x)
    (matcher = declRefExpr(to(varDecl(hasName("x")))))
  bool x;
  if (x) {}

Matches the n'th declaration of a declaration statement.

Note that this does not work for global declarations because the AST
breaks up multiple-declaration DeclStmt's into multiple single-declaration
DeclStmt's.
Example: Given non-global declarations
  int a, b = 0;
  int c;
  int d = 2, e;
declStmt(containsDeclaration(
      0, varDecl(hasInitializer(anything()))))
  matches only 'int d = 2, e;', and
declStmt(containsDeclaration(1, varDecl()))
  matches 'int a, b = 0' as well as 'int d = 2, e;'
  but 'int c;' is not matched.

Matches the Decl of a DeclStmt which has a single declaration.

Given
  int a, b;
  int c;
declStmt(hasSingleDecl(anything()))
  matches 'int c;' but not 'int a, b;'.

Matches if the type location of the declarator decl's type matches
the inner matcher.

Given
  int x;
declaratorDecl(hasTypeLoc(loc(asString("int"))))
  matches int x

Matches declarations whose declaration context, interpreted as a
Decl, matches InnerMatcher.

Given
  namespace N {
    namespace M {
      class D {};
    }
  }

cxxRcordDecl(hasDeclContext(namedDecl(hasName("M")))) matches the
declaration of class D.

Matches a 'for', 'while', 'do while' statement or a function
definition that has a given body.

Given
  for (;;) {}
hasBody(compoundStmt())
  matches 'for (;;) {}'
with compoundStmt()
  matching '{}'

Matches the condition expression of an if statement, for loop,
or conditional operator.

Example matches true (matcher = hasCondition(cxxBoolLiteral(equals(true))))
  if (true) {}

Matches ElaboratedTypes whose qualifier, a NestedNameSpecifier,
matches InnerMatcher if the qualifier exists.

Given
  namespace N {
    namespace M {
      class D {};
    }
  }
  N::M::D d;

elaboratedType(hasQualifier(hasPrefix(specifiesNamespace(hasName("N"))))
matches the type of the variable declaration of d.

Matches ElaboratedTypes whose named type matches InnerMatcher.

Given
  namespace N {
    namespace M {
      class D {};
    }
  }
  N::M::D d;

elaboratedType(namesType(recordType(
hasDeclaration(namedDecl(hasName("D")))))) matches the type of the variable
declaration of d.

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches casts whose destination type matches a given matcher.

(Note: Clang's AST refers to other conversions as "casts" too, and calls
actual casts "explicit" casts.)

Overloaded to match the declaration of the expression's or value
declaration's type.

In case of a value declaration (for example a variable declaration),
this resolves one layer of indirection. For example, in the value
declaration "X x;", cxxRecordDecl(hasName("X")) matches the declaration of
X, while varDecl(hasType(cxxRecordDecl(hasName("X")))) matches the
declaration of x.

Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
            and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
 class X {};
 void y(X &x) { x; X z; }

Usable as: Matcher<Expr>, Matcher<ValueDecl>

Matches if the expression's or declaration's type matches a type
matcher.

Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
            and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
            and U (matcher = typedefDecl(hasType(asString("int")))
 class X {};
 void y(X &x) { x; X z; }
 typedef int U;

Matches expressions that match InnerMatcher after any implicit casts
are stripped off.

Parentheses and explicit casts are not discarded.
Given
  int arr[5];
  int a = 0;
  char b = 0;
  const int c = a;
  int *d = arr;
  long e = (long) 0l;
The matchers
   varDecl(hasInitializer(ignoringImpCasts(integerLiteral())))
   varDecl(hasInitializer(ignoringImpCasts(declRefExpr())))
would match the declarations for a, b, c, and d, but not e.
While
   varDecl(hasInitializer(integerLiteral()))
   varDecl(hasInitializer(declRefExpr()))
only match the declarations for b, c, and d.

Matches expressions that match InnerMatcher after parentheses and
casts are stripped off.

Implicit and non-C Style casts are also discarded.
Given
  int a = 0;
  char b = (0);
  void* c = reinterpret_cast<char*>(0);
  char d = char(0);
The matcher
   varDecl(hasInitializer(ignoringParenCasts(integerLiteral())))
would match the declarations for a, b, c, and d.
while
   varDecl(hasInitializer(integerLiteral()))
only match the declaration for a.

Matches expressions that match InnerMatcher after implicit casts and
parentheses are stripped off.

Explicit casts are not discarded.
Given
  int arr[5];
  int a = 0;
  char b = (0);
  const int c = a;
  int *d = (arr);
  long e = ((long) 0l);
The matchers
   varDecl(hasInitializer(ignoringParenImpCasts(integerLiteral())))
   varDecl(hasInitializer(ignoringParenImpCasts(declRefExpr())))
would match the declarations for a, b, c, and d, but not e.
while
   varDecl(hasInitializer(integerLiteral()))
   varDecl(hasInitializer(declRefExpr()))
would only match the declaration for a.

Matches a 'for', 'while', 'do while' statement or a function
definition that has a given body.

Given
  for (;;) {}
hasBody(compoundStmt())
  matches 'for (;;) {}'
with compoundStmt()
  matching '{}'

Matches the condition expression of an if statement, for loop,
or conditional operator.

Example matches true (matcher = hasCondition(cxxBoolLiteral(equals(true))))
  if (true) {}

Matches the increment statement of a for loop.

Example:
    forStmt(hasIncrement(unaryOperator(hasOperatorName("++"))))
matches '++x' in
    for (x; x < N; ++x) { }

Matches the initialization statement of a for loop.

Example:
    forStmt(hasLoopInit(declStmt()))
matches 'int x = 0' in
    for (int x = 0; x < N; ++x) { }

Matches any parameter of a function declaration.

Does not match the 'this' parameter of a method.

Given
  class X { void f(int x, int y, int z) {} };
cxxMethodDecl(hasAnyParameter(hasName("y")))
  matches f(int x, int y, int z) {}
with hasAnyParameter(...)
  matching int y

Matches a 'for', 'while', 'do while' statement or a function
definition that has a given body.

Given
  for (;;) {}
hasBody(compoundStmt())
  matches 'for (;;) {}'
with compoundStmt()
  matching '{}'

Matches the n'th parameter of a function declaration.

Given
  class X { void f(int x) {} };
cxxMethodDecl(hasParameter(0, hasType(varDecl())))
  matches f(int x) {}
with hasParameter(...)
  matching int x

Matches the return type of a function declaration.

Given:
  class X { int f() { return 1; } };
cxxMethodDecl(returns(asString("int")))
  matches int f() { return 1; }

Matches the condition expression of an if statement, for loop,
or conditional operator.

Example matches true (matcher = hasCondition(cxxBoolLiteral(equals(true))))
  if (true) {}

Matches the condition variable statement in an if statement.

Given
  if (A* a = GetAPointer()) {}
hasConditionVariableStatement(...)
  matches 'A* a = GetAPointer()'.

Matches the else-statement of an if statement.

Examples matches the if statement
  (matcher = ifStmt(hasElse(cxxBoolLiteral(equals(true)))))
  if (false) false; else true;

Matches the then-statement of an if statement.

Examples matches the if statement
  (matcher = ifStmt(hasThen(cxxBoolLiteral(equals(true)))))
  if (false) true; else false;

Matches implicit casts whose destination type matches a given
matcher.

FIXME: Unit test this matcher

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches a member expression where the object expression is
matched by a given matcher.

Given
  struct X { int m; };
  void f(X x) { x.m; m; }
memberExpr(hasObjectExpression(hasType(cxxRecordDecl(hasName("X")))))))
  matches "x.m" and "m"
with hasObjectExpression(...)
  matching "x" and the implicit object expression of "m" which has type X*.

Matches a member expression where the member is matched by a
given matcher.

Given
  struct { int first, second; } first, second;
  int i(second.first);
  int j(first.second);
memberExpr(member(hasName("first")))
  matches second.first
  but not first.second (because the member name there is "second").

Narrows PointerType (and similar) matchers to those where the
pointee matches a given matcher.

Given
  int *a;
  int const *b;
  float const *f;
pointerType(pointee(isConstQualified(), isInteger()))
  matches "int const *b"

Usable as: Matcher<BlockPointerType>, Matcher<MemberPointerType>,
  Matcher<PointerType>, Matcher<ReferenceType>

Narrows PointerType (and similar) matchers to those where the
pointee matches a given matcher.

Given
  int *a;
  int const *b;
  float const *f;
pointerType(pointee(isConstQualified(), isInteger()))
  matches "int const *b"

Usable as: Matcher<BlockPointerType>, Matcher<MemberPointerType>,
  Matcher<PointerType>, Matcher<ReferenceType>

Matches on the prefix of a NestedNameSpecifierLoc.

Given
  struct A { struct B { struct C {}; }; };
  A::B::C c;
nestedNameSpecifierLoc(hasPrefix(loc(specifiesType(asString("struct A")))))
  matches "A::"

Matches nested name specifier locs that specify a type matching the
given TypeLoc.

Given
  struct A { struct B { struct C {}; }; };
  A::B::C c;
nestedNameSpecifierLoc(specifiesTypeLoc(loc(type(
  hasDeclaration(cxxRecordDecl(hasName("A")))))))
  matches "A::"

Matches on the prefix of a NestedNameSpecifier.

Given
  struct A { struct B { struct C {}; }; };
  A::B::C c;
nestedNameSpecifier(hasPrefix(specifiesType(asString("struct A")))) and
  matches "A::"

Matches nested name specifiers that specify a namespace matching the
given namespace matcher.

Given
  namespace ns { struct A {}; }
  ns::A a;
nestedNameSpecifier(specifiesNamespace(hasName("ns")))
  matches "ns::"

Matches nested name specifiers that specify a type matching the
given QualType matcher without qualifiers.

Given
  struct A { struct B { struct C {}; }; };
  A::B::C c;
nestedNameSpecifier(specifiesType(
  hasDeclaration(cxxRecordDecl(hasName("A")))
))
  matches "A::"

Matches the n'th argument of a call expression or a constructor
call expression.

Example matches y in x(y)
    (matcher = callExpr(hasArgument(0, declRefExpr())))
  void x(int) { int y; x(y); }

Matches on the receiver of an ObjectiveC Message expression.

Example
matcher = objCMessageExpr(hasRecieverType(asString("UIWebView *")));
matches the [webView ...] message invocation.
  NSString *webViewJavaScript = ...
  UIWebView *webView = ...
  [webView stringByEvaluatingJavaScriptFromString:webViewJavascript];

Matches ParenType nodes where the inner type is a specific type.

Given
  int (*ptr_to_array)[4];
  int (*ptr_to_func)(int);

varDecl(hasType(pointsTo(parenType(innerType(functionType()))))) matches
ptr_to_func but not ptr_to_array.

Usable as: Matcher<ParenType>

Narrows PointerType (and similar) matchers to those where the
pointee matches a given matcher.

Given
  int *a;
  int const *b;
  float const *f;
pointerType(pointee(isConstQualified(), isInteger()))
  matches "int const *b"

Usable as: Matcher<BlockPointerType>, Matcher<MemberPointerType>,
  Matcher<PointerType>, Matcher<ReferenceType>

Narrows PointerType (and similar) matchers to those where the
pointee matches a given matcher.

Given
  int *a;
  int const *b;
  float const *f;
pointerType(pointee(isConstQualified(), isInteger()))
  matches "int const *b"

Usable as: Matcher<BlockPointerType>, Matcher<MemberPointerType>,
  Matcher<PointerType>, Matcher<ReferenceType>

Matches QualTypes whose canonical type matches InnerMatcher.

Given:
  typedef int &int_ref;
  int a;
  int_ref b = a;

varDecl(hasType(qualType(referenceType()))))) will not match the
declaration of b but varDecl(hasType(qualType(hasCanonicalType(referenceType())))))) does.

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Overloaded to match the pointee type's declaration.

Matches if the matched type is a pointer type and the pointee type
matches the specified matcher.

Example matches y->x()
  (matcher = cxxMemberCallExpr(on(hasType(pointsTo
     cxxRecordDecl(hasName("Y")))))))
  class Y { public: void x(); };
  void z() { Y *y; y->x(); }

Overloaded to match the referenced type's declaration.

Matches if the matched type is a reference type and the referenced
type matches the specified matcher.

Example matches X &x and const X &y
    (matcher = varDecl(hasType(references(cxxRecordDecl(hasName("X"))))))
  class X {
    void a(X b) {
      X &x = b;
      const X &y = b;
    }
  };

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Narrows PointerType (and similar) matchers to those where the
pointee matches a given matcher.

Given
  int *a;
  int const *b;
  float const *f;
pointerType(pointee(isConstQualified(), isInteger()))
  matches "int const *b"

Usable as: Matcher<BlockPointerType>, Matcher<MemberPointerType>,
  Matcher<PointerType>, Matcher<ReferenceType>

Narrows PointerType (and similar) matchers to those where the
pointee matches a given matcher.

Given
  int *a;
  int const *b;
  float const *f;
pointerType(pointee(isConstQualified(), isInteger()))
  matches "int const *b"

Usable as: Matcher<BlockPointerType>, Matcher<MemberPointerType>,
  Matcher<PointerType>, Matcher<ReferenceType>

Same as unaryExprOrTypeTraitExpr, but only matching
alignof.

Same as unaryExprOrTypeTraitExpr, but only matching
sizeof.

Matches each case or default statement belonging to the given switch
statement. This matcher may produce multiple matches.

Given
  switch (1) { case 1: case 2: default: switch (2) { case 3: case 4: ; } }
switchStmt(forEachSwitchCase(caseStmt().bind("c"))).bind("s")
  matches four times, with "c" binding each of "case 1:", "case 2:",
"case 3:" and "case 4:", and "s" respectively binding "switch (1)",
"switch (1)", "switch (2)" and "switch (2)".

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches a sugar TemplateArgument that refers to a certain expression.

Given
  template<typename T> struct A {};
  struct B { B* next; };
  A<&B::next> a;
templateSpecializationType(hasAnyTemplateArgument(
  isExpr(hasDescendant(declRefExpr(to(fieldDecl(hasName("next"))))))))
  matches the specialization A<&B::next> with fieldDecl(...) matching
    B::next

Matches a canonical TemplateArgument that refers to a certain
declaration.

Given
  template<typename T> struct A {};
  struct B { B* next; };
  A<&B::next> a;
classTemplateSpecializationDecl(hasAnyTemplateArgument(
    refersToDeclaration(fieldDecl(hasName("next"))))
  matches the specialization A<&B::next> with fieldDecl(...) matching
    B::next

Matches a TemplateArgument that referes to an integral type.

Given
  template<int T> struct A {};
  C<42> c;
classTemplateSpecializationDecl(
  hasAnyTemplateArgument(refersToIntegralType(asString("int"))))
  matches the implicit instantiation of C in C<42>.

Matches a TemplateArgument that refers to a certain type.

Given
  struct X {};
  template<typename T> struct A {};
  A<X> a;
classTemplateSpecializationDecl(hasAnyTemplateArgument(
    refersToType(class(hasName("X")))))
  matches the specialization A<X>

Matches classTemplateSpecializations that have at least one
TemplateArgument matching the given InnerMatcher.

Given
  template<typename T> class A {};
  template<> class A<double> {};
  A<int> a;
classTemplateSpecializationDecl(hasAnyTemplateArgument(
    refersToType(asString("int"))))
  matches the specialization A<int>

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches classTemplateSpecializations where the n'th TemplateArgument
matches the given InnerMatcher.

Given
  template<typename T, typename U> class A {};
  A<bool, int> b;
  A<int, bool> c;
classTemplateSpecializationDecl(hasTemplateArgument(
    1, refersToType(asString("int"))))
  matches the specialization A<bool, int>

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches if the node or any descendant matches.

Generates results for each match.

For example, in:
  class A { class B {}; class C {}; };
The matcher:
  cxxRecordDecl(hasName("::A"),
                findAll(cxxRecordDecl(isDefinition()).bind("m")))
will generate results for A, B and C.

Usable as: Any Matcher

Matches if the expression's or declaration's type matches a type
matcher.

Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
            and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
            and U (matcher = typedefDecl(hasType(asString("int")))
 class X {};
 void y(X &x) { x; X z; }
 typedef int U;

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches unary expressions that have a specific type of argument.

Given
  int a, c; float b; int s = sizeof(a) + sizeof(b) + alignof(c);
unaryExprOrTypeTraitExpr(hasArgumentOfType(asString("int"))
  matches sizeof(a) and alignof(c)

Matches if the operand of a unary operator matches.

Example matches true (matcher = hasUnaryOperand(
                                  cxxBoolLiteral(equals(true))))
  !true

Matches a node if the declaration associated with that node
matches the given matcher.

The associated declaration is:
- for type nodes, the declaration of the underlying type
- for CallExpr, the declaration of the callee
- for MemberExpr, the declaration of the referenced member
- for CXXConstructExpr, the declaration of the constructor

Also usable as Matcher<T> for any T supporting the getDecl() member
function. e.g. various subtypes of clang::Type and various expressions.

Usable as: Matcher<CallExpr>, Matcher<CXXConstructExpr>,
  Matcher<DeclRefExpr>, Matcher<EnumType>, Matcher<InjectedClassNameType>,
  Matcher<LabelStmt>, Matcher<MemberExpr>, Matcher<QualType>,
  Matcher<RecordType>, Matcher<TagType>,
  Matcher<TemplateSpecializationType>, Matcher<TemplateTypeParmType>,
  Matcher<TypedefType>, Matcher<UnresolvedUsingType>

Matches any using shadow declaration.

Given
  namespace X { void b(); }
  using X::b;
usingDecl(hasAnyUsingShadowDecl(hasName("b"))))
  matches using X::b 

Matches a using shadow declaration where the target declaration is
matched by the given matcher.

Given
  namespace X { int a; void b(); }
  using X::a;
  using X::b;
usingDecl(hasAnyUsingShadowDecl(hasTargetDecl(functionDecl())))
  matches using X::b but not using X::a 

Overloaded to match the declaration of the expression's or value
declaration's type.

In case of a value declaration (for example a variable declaration),
this resolves one layer of indirection. For example, in the value
declaration "X x;", cxxRecordDecl(hasName("X")) matches the declaration of
X, while varDecl(hasType(cxxRecordDecl(hasName("X")))) matches the
declaration of x.

Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
            and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
 class X {};
 void y(X &x) { x; X z; }

Usable as: Matcher<Expr>, Matcher<ValueDecl>

Matches if the expression's or declaration's type matches a type
matcher.

Example matches x (matcher = expr(hasType(cxxRecordDecl(hasName("X")))))
            and z (matcher = varDecl(hasType(cxxRecordDecl(hasName("X")))))
            and U (matcher = typedefDecl(hasType(asString("int")))
 class X {};
 void y(X &x) { x; X z; }
 typedef int U;

Matches a variable declaration that has an initializer expression
that matches the given matcher.

Example matches x (matcher = varDecl(hasInitializer(callExpr())))
  bool y() { return true; }
  bool x = y();

Matches VariableArrayType nodes that have a specific size
expression.

Given
  void f(int b) {
    int a[b];
  }
variableArrayType(hasSizeExpr(ignoringImpCasts(declRefExpr(to(
  varDecl(hasName("b")))))))
  matches "int a[b]"

Matches a 'for', 'while', 'do while' statement or a function
definition that has a given body.

Given
  for (;;) {}
hasBody(compoundStmt())
  matches 'for (;;) {}'
with compoundStmt()
  matching '{}'

Matches the condition expression of an if statement, for loop,
or conditional operator.

Example matches true (matcher = hasCondition(cxxBoolLiteral(equals(true))))
  if (true) {}

Matches NestedNameSpecifierLocs for which the given inner
NestedNameSpecifier-matcher matches.

Matches TypeLocs for which the given inner
QualType-matcher matches.