diff options
Diffstat (limited to 'libcxx/include/__expected/expected.h')
| -rw-r--r-- | libcxx/include/__expected/expected.h | 618 |
1 files changed, 22 insertions, 596 deletions
diff --git a/libcxx/include/__expected/expected.h b/libcxx/include/__expected/expected.h index 668e23f21c71..3ff8fbc7b211 100644 --- a/libcxx/include/__expected/expected.h +++ b/libcxx/include/__expected/expected.h @@ -14,12 +14,10 @@ #include <__expected/bad_expected_access.h> #include <__expected/unexpect.h> #include <__expected/unexpected.h> -#include <__functional/invoke.h> #include <__memory/addressof.h> #include <__memory/construct_at.h> #include <__type_traits/conjunction.h> #include <__type_traits/disjunction.h> -#include <__type_traits/integral_constant.h> #include <__type_traits/is_assignable.h> #include <__type_traits/is_constructible.h> #include <__type_traits/is_convertible.h> @@ -62,17 +60,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD -template <class _Tp, class _Err> -class expected; - -template <class _Tp> -struct __is_std_expected : false_type {}; - -template <class _Tp, class _Err> -struct __is_std_expected<expected<_Tp, _Err>> : true_type {}; - -struct __expected_construct_in_place_from_invoke_tag {}; -struct __expected_construct_unexpected_from_invoke_tag {}; +namespace __expected { template <class _Err, class _Arg> _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) { @@ -84,6 +72,8 @@ _LIBCPP_HIDE_FROM_ABI void __throw_bad_expected_access(_Arg&& __arg) { # endif } +} // namespace __expected + template <class _Tp, class _Err> class expected { static_assert( @@ -176,15 +166,6 @@ private: _Not<is_constructible<unexpected<_Err>, const expected<_Up, _OtherErr>&>>, _Not<is_constructible<unexpected<_Err>, const expected<_Up, _OtherErr>>> >; - template <class _Func, class... _Args> - _LIBCPP_HIDE_FROM_ABI constexpr explicit expected( - std::__expected_construct_in_place_from_invoke_tag __tag, _Func&& __f, _Args&&... __args) - : __union_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...), __has_val_(true) {} - - template <class _Func, class... _Args> - _LIBCPP_HIDE_FROM_ABI constexpr explicit expected( - std::__expected_construct_unexpected_from_invoke_tag __tag, _Func&& __f, _Args&&... __args) - : __union_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...), __has_val_(false) {} public: template <class _Up, class _OtherErr> @@ -557,28 +538,28 @@ public: _LIBCPP_HIDE_FROM_ABI constexpr const _Tp& value() const& { if (!__has_val_) { - std::__throw_bad_expected_access<_Err>(__union_.__unex_); + __expected::__throw_bad_expected_access<_Err>(__union_.__unex_); } return __union_.__val_; } _LIBCPP_HIDE_FROM_ABI constexpr _Tp& value() & { if (!__has_val_) { - std::__throw_bad_expected_access<_Err>(__union_.__unex_); + __expected::__throw_bad_expected_access<_Err>(__union_.__unex_); } return __union_.__val_; } _LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& value() const&& { if (!__has_val_) { - std::__throw_bad_expected_access<_Err>(std::move(__union_.__unex_)); + __expected::__throw_bad_expected_access<_Err>(std::move(__union_.__unex_)); } return std::move(__union_.__val_); } _LIBCPP_HIDE_FROM_ABI constexpr _Tp&& value() && { if (!__has_val_) { - std::__throw_bad_expected_access<_Err>(std::move(__union_.__unex_)); + __expected::__throw_bad_expected_access<_Err>(std::move(__union_.__unex_)); } return std::move(__union_.__val_); } @@ -617,245 +598,6 @@ public: return __has_val_ ? std::move(__union_.__val_) : static_cast<_Tp>(std::forward<_Up>(__v)); } - template <class _Up = _Err> - _LIBCPP_HIDE_FROM_ABI constexpr _Err error_or(_Up&& __error) const& { - static_assert(is_copy_constructible_v<_Err>, "error_type has to be copy constructible"); - static_assert(is_convertible_v<_Up, _Err>, "argument has to be convertible to error_type"); - if (has_value()) - return std::forward<_Up>(__error); - return error(); - } - - template <class _Up = _Err> - _LIBCPP_HIDE_FROM_ABI constexpr _Err error_or(_Up&& __error) && { - static_assert(is_move_constructible_v<_Err>, "error_type has to be move constructible"); - static_assert(is_convertible_v<_Up, _Err>, "argument has to be convertible to error_type"); - if (has_value()) - return std::forward<_Up>(__error); - return std::move(error()); - } - - // [expected.void.monadic], monadic - template <class _Func> - requires is_constructible_v<_Err, _Err&> - _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) & { - using _Up = remove_cvref_t<invoke_result_t<_Func, _Tp&>>; - static_assert(__is_std_expected<_Up>::value, "The result of f(value()) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Up::error_type, _Err>, - "The result of f(value()) must have the same error_type as this expected"); - if (has_value()) { - return std::invoke(std::forward<_Func>(__f), value()); - } - return _Up(unexpect, error()); - } - - template <class _Func> - requires is_constructible_v<_Err, const _Err&> - _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) const& { - using _Up = remove_cvref_t<invoke_result_t<_Func, const _Tp&>>; - static_assert(__is_std_expected<_Up>::value, "The result of f(value()) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Up::error_type, _Err>, - "The result of f(value()) must have the same error_type as this expected"); - if (has_value()) { - return std::invoke(std::forward<_Func>(__f), value()); - } - return _Up(unexpect, error()); - } - - template <class _Func> - requires is_constructible_v<_Err, _Err&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) && { - using _Up = remove_cvref_t<invoke_result_t<_Func, _Tp&&>>; - static_assert( - __is_std_expected<_Up>::value, "The result of f(std::move(value())) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Up::error_type, _Err>, - "The result of f(std::move(value())) must have the same error_type as this expected"); - if (has_value()) { - return std::invoke(std::forward<_Func>(__f), std::move(value())); - } - return _Up(unexpect, std::move(error())); - } - - template <class _Func> - requires is_constructible_v<_Err, const _Err&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) const&& { - using _Up = remove_cvref_t<invoke_result_t<_Func, const _Tp&&>>; - static_assert( - __is_std_expected<_Up>::value, "The result of f(std::move(value())) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Up::error_type, _Err>, - "The result of f(std::move(value())) must have the same error_type as this expected"); - if (has_value()) { - return std::invoke(std::forward<_Func>(__f), std::move(value())); - } - return _Up(unexpect, std::move(error())); - } - - template <class _Func> - requires is_constructible_v<_Tp, _Tp&> - _LIBCPP_HIDE_FROM_ABI constexpr auto or_else(_Func&& __f) & { - using _Gp = remove_cvref_t<invoke_result_t<_Func, _Err&>>; - static_assert(__is_std_expected<_Gp>::value, "The result of f(error()) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Gp::value_type, _Tp>, - "The result of f(error()) must have the same value_type as this expected"); - if (has_value()) { - return _Gp(in_place, value()); - } - return std::invoke(std::forward<_Func>(__f), error()); - } - - template <class _Func> - requires is_constructible_v<_Tp, const _Tp&> - _LIBCPP_HIDE_FROM_ABI constexpr auto or_else(_Func&& __f) const& { - using _Gp = remove_cvref_t<invoke_result_t<_Func, const _Err&>>; - static_assert(__is_std_expected<_Gp>::value, "The result of f(error()) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Gp::value_type, _Tp>, - "The result of f(error()) must have the same value_type as this expected"); - if (has_value()) { - return _Gp(in_place, value()); - } - return std::invoke(std::forward<_Func>(__f), error()); - } - - template <class _Func> - requires is_constructible_v<_Tp, _Tp&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto or_else(_Func&& __f) && { - using _Gp = remove_cvref_t<invoke_result_t<_Func, _Err&&>>; - static_assert( - __is_std_expected<_Gp>::value, "The result of f(std::move(error())) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Gp::value_type, _Tp>, - "The result of f(std::move(error())) must have the same value_type as this expected"); - if (has_value()) { - return _Gp(in_place, std::move(value())); - } - return std::invoke(std::forward<_Func>(__f), std::move(error())); - } - - template <class _Func> - requires is_constructible_v<_Tp, const _Tp&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto or_else(_Func&& __f) const&& { - using _Gp = remove_cvref_t<invoke_result_t<_Func, const _Err&&>>; - static_assert( - __is_std_expected<_Gp>::value, "The result of f(std::move(error())) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Gp::value_type, _Tp>, - "The result of f(std::move(error())) must have the same value_type as this expected"); - if (has_value()) { - return _Gp(in_place, std::move(value())); - } - return std::invoke(std::forward<_Func>(__f), std::move(error())); - } - - template <class _Func> - requires is_constructible_v<_Err, _Err&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) & { - using _Up = remove_cv_t<invoke_result_t<_Func, _Tp&>>; - if (!has_value()) { - return expected<_Up, _Err>(unexpect, error()); - } - if constexpr (!is_void_v<_Up>) { - return expected<_Up, _Err>(__expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), value()); - } else { - std::invoke(std::forward<_Func>(__f), value()); - return expected<_Up, _Err>(); - } - } - - template <class _Func> - requires is_constructible_v<_Err, const _Err&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) const& { - using _Up = remove_cv_t<invoke_result_t<_Func, const _Tp&>>; - if (!has_value()) { - return expected<_Up, _Err>(unexpect, error()); - } - if constexpr (!is_void_v<_Up>) { - return expected<_Up, _Err>(__expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), value()); - } else { - std::invoke(std::forward<_Func>(__f), value()); - return expected<_Up, _Err>(); - } - } - - template <class _Func> - requires is_constructible_v<_Err, _Err&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) && { - using _Up = remove_cv_t<invoke_result_t<_Func, _Tp&&>>; - if (!has_value()) { - return expected<_Up, _Err>(unexpect, std::move(error())); - } - if constexpr (!is_void_v<_Up>) { - return expected<_Up, _Err>( - __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), std::move(value())); - } else { - std::invoke(std::forward<_Func>(__f), std::move(value())); - return expected<_Up, _Err>(); - } - } - - template <class _Func> - requires is_constructible_v<_Err, const _Err&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) const&& { - using _Up = remove_cv_t<invoke_result_t<_Func, const _Tp&&>>; - if (!has_value()) { - return expected<_Up, _Err>(unexpect, std::move(error())); - } - if constexpr (!is_void_v<_Up>) { - return expected<_Up, _Err>( - __expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f), std::move(value())); - } else { - std::invoke(std::forward<_Func>(__f), std::move(value())); - return expected<_Up, _Err>(); - } - } - - template <class _Func> - requires is_constructible_v<_Tp, _Tp&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform_error(_Func&& __f) & { - using _Gp = remove_cv_t<invoke_result_t<_Func, _Err&>>; - static_assert(__valid_std_unexpected<_Gp>::value, - "The result of f(error()) must be a valid template argument for unexpected"); - if (has_value()) { - return expected<_Tp, _Gp>(in_place, value()); - } - return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error()); - } - - template <class _Func> - requires is_constructible_v<_Tp, const _Tp&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform_error(_Func&& __f) const& { - using _Gp = remove_cv_t<invoke_result_t<_Func, const _Err&>>; - static_assert(__valid_std_unexpected<_Gp>::value, - "The result of f(error()) must be a valid template argument for unexpected"); - if (has_value()) { - return expected<_Tp, _Gp>(in_place, value()); - } - return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error()); - } - - template <class _Func> - requires is_constructible_v<_Tp, _Tp&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform_error(_Func&& __f) && { - using _Gp = remove_cv_t<invoke_result_t<_Func, _Err&&>>; - static_assert(__valid_std_unexpected<_Gp>::value, - "The result of f(std::move(error())) must be a valid template argument for unexpected"); - if (has_value()) { - return expected<_Tp, _Gp>(in_place, std::move(value())); - } - return expected<_Tp, _Gp>( - __expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error())); - } - - template <class _Func> - requires is_constructible_v<_Tp, const _Tp&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform_error(_Func&& __f) const&& { - using _Gp = remove_cv_t<invoke_result_t<_Func, const _Err&&>>; - static_assert(__valid_std_unexpected<_Gp>::value, - "The result of f(std::move(error())) must be a valid template argument for unexpected"); - if (has_value()) { - return expected<_Tp, _Gp>(in_place, std::move(value())); - } - return expected<_Tp, _Gp>( - __expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error())); - } - // [expected.object.eq], equality operators template <class _T2, class _E2> requires(!is_void_v<_T2>) @@ -883,66 +625,24 @@ public: private: struct __empty_t {}; - - template <class _ValueType, class _ErrorType> - union __union_t { - _LIBCPP_HIDE_FROM_ABI constexpr __union_t() {} - - template <class _Func, class... _Args> - _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t( - std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args) - : __val_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {} - - template <class _Func, class... _Args> - _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t( - std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args) - : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {} - - _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() - requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>) - = default; - - // the expected's destructor handles this - _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() {} - - _ValueType __val_; - _ErrorType __unex_; - }; - - // use named union because [[no_unique_address]] cannot be applied to an unnamed union, - // also guaranteed elision into a potentially-overlapping subobject is unsettled (and - // it's not clear that it's implementable, given that the function is allowed to clobber - // the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107. - template <class _ValueType, class _ErrorType> - requires(is_trivially_move_constructible_v<_ValueType> && is_trivially_move_constructible_v<_ErrorType>) - union __union_t<_ValueType, _ErrorType> { + // use named union because [[no_unique_address]] cannot be applied to an unnamed union + _LIBCPP_NO_UNIQUE_ADDRESS union __union_t { _LIBCPP_HIDE_FROM_ABI constexpr __union_t() : __empty_() {} - template <class _Func, class... _Args> - _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t( - std::__expected_construct_in_place_from_invoke_tag, _Func&& __f, _Args&&... __args) - : __val_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {} - - template <class _Func, class... _Args> - _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t( - std::__expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args) - : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {} - _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() - requires(is_trivially_destructible_v<_ValueType> && is_trivially_destructible_v<_ErrorType>) + requires(is_trivially_destructible_v<_Tp> && is_trivially_destructible_v<_Err>) = default; // the expected's destructor handles this _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() - requires(!is_trivially_destructible_v<_ValueType> || !is_trivially_destructible_v<_ErrorType>) + requires(!is_trivially_destructible_v<_Tp> || !is_trivially_destructible_v<_Err>) {} _LIBCPP_NO_UNIQUE_ADDRESS __empty_t __empty_; - _LIBCPP_NO_UNIQUE_ADDRESS _ValueType __val_; - _LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_; - }; + _LIBCPP_NO_UNIQUE_ADDRESS _Tp __val_; + _LIBCPP_NO_UNIQUE_ADDRESS _Err __unex_; + } __union_; - _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Tp, _Err> __union_; bool __has_val_; }; @@ -1062,19 +762,6 @@ public: std::construct_at(std::addressof(__union_.__unex_), __il, std::forward<_Args>(__args)...); } -private: - template <class _Func> - _LIBCPP_HIDE_FROM_ABI constexpr explicit expected(__expected_construct_in_place_from_invoke_tag, _Func&& __f) - : __has_val_(true) { - std::invoke(std::forward<_Func>(__f)); - } - - template <class _Func, class... _Args> - _LIBCPP_HIDE_FROM_ABI constexpr explicit expected( - __expected_construct_unexpected_from_invoke_tag __tag, _Func&& __f, _Args&&... __args) - : __union_(__tag, std::forward<_Func>(__f), std::forward<_Args>(__args)...), __has_val_(false) {} - -public: // [expected.void.dtor], destructor _LIBCPP_HIDE_FROM_ABI constexpr ~expected() @@ -1212,13 +899,13 @@ public: _LIBCPP_HIDE_FROM_ABI constexpr void value() const& { if (!__has_val_) { - std::__throw_bad_expected_access<_Err>(__union_.__unex_); + __expected::__throw_bad_expected_access<_Err>(__union_.__unex_); } } _LIBCPP_HIDE_FROM_ABI constexpr void value() && { if (!__has_val_) { - std::__throw_bad_expected_access<_Err>(std::move(__union_.__unex_)); + __expected::__throw_bad_expected_access<_Err>(std::move(__union_.__unex_)); } } @@ -1242,235 +929,6 @@ public: return std::move(__union_.__unex_); } - template <class _Up = _Err> - _LIBCPP_HIDE_FROM_ABI constexpr _Err error_or(_Up&& __error) const& { - static_assert(is_copy_constructible_v<_Err>, "error_type has to be copy constructible"); - static_assert(is_convertible_v<_Up, _Err>, "argument has to be convertible to error_type"); - if (has_value()) { - return std::forward<_Up>(__error); - } - return error(); - } - - template <class _Up = _Err> - _LIBCPP_HIDE_FROM_ABI constexpr _Err error_or(_Up&& __error) && { - static_assert(is_move_constructible_v<_Err>, "error_type has to be move constructible"); - static_assert(is_convertible_v<_Up, _Err>, "argument has to be convertible to error_type"); - if (has_value()) { - return std::forward<_Up>(__error); - } - return std::move(error()); - } - - // [expected.void.monadic], monadic - template <class _Func> - requires is_constructible_v<_Err, _Err&> - _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) & { - using _Up = remove_cvref_t<invoke_result_t<_Func>>; - static_assert(__is_std_expected<_Up>::value, "The result of f() must be a specialization of std::expected"); - static_assert( - is_same_v<typename _Up::error_type, _Err>, "The result of f() must have the same error_type as this expected"); - if (has_value()) { - return std::invoke(std::forward<_Func>(__f)); - } - return _Up(unexpect, error()); - } - - template <class _Func> - requires is_constructible_v<_Err, const _Err&> - _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) const& { - using _Up = remove_cvref_t<invoke_result_t<_Func>>; - static_assert(__is_std_expected<_Up>::value, "The result of f() must be a specialization of std::expected"); - static_assert( - is_same_v<typename _Up::error_type, _Err>, "The result of f() must have the same error_type as this expected"); - if (has_value()) { - return std::invoke(std::forward<_Func>(__f)); - } - return _Up(unexpect, error()); - } - - template <class _Func> - requires is_constructible_v<_Err, _Err&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) && { - using _Up = remove_cvref_t<invoke_result_t<_Func>>; - static_assert(__is_std_expected<_Up>::value, "The result of f() must be a specialization of std::expected"); - static_assert( - is_same_v<typename _Up::error_type, _Err>, "The result of f() must have the same error_type as this expected"); - if (has_value()) { - return std::invoke(std::forward<_Func>(__f)); - } - return _Up(unexpect, std::move(error())); - } - - template <class _Func> - requires is_constructible_v<_Err, const _Err&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) const&& { - using _Up = remove_cvref_t<invoke_result_t<_Func>>; - static_assert(__is_std_expected<_Up>::value, "The result of f() must be a specialization of std::expected"); - static_assert( - is_same_v<typename _Up::error_type, _Err>, "The result of f() must have the same error_type as this expected"); - if (has_value()) { - return std::invoke(std::forward<_Func>(__f)); - } - return _Up(unexpect, std::move(error())); - } - - template <class _Func> - _LIBCPP_HIDE_FROM_ABI constexpr auto or_else(_Func&& __f) & { - using _Gp = remove_cvref_t<invoke_result_t<_Func, _Err&>>; - static_assert(__is_std_expected<_Gp>::value, "The result of f(error()) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Gp::value_type, _Tp>, - "The result of f(error()) must have the same value_type as this expected"); - if (has_value()) { - return _Gp(); - } - return std::invoke(std::forward<_Func>(__f), error()); - } - - template <class _Func> - _LIBCPP_HIDE_FROM_ABI constexpr auto or_else(_Func&& __f) const& { - using _Gp = remove_cvref_t<invoke_result_t<_Func, const _Err&>>; - static_assert(__is_std_expected<_Gp>::value, "The result of f(error()) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Gp::value_type, _Tp>, - "The result of f(error()) must have the same value_type as this expected"); - if (has_value()) { - return _Gp(); - } - return std::invoke(std::forward<_Func>(__f), error()); - } - - template <class _Func> - _LIBCPP_HIDE_FROM_ABI constexpr auto or_else(_Func&& __f) && { - using _Gp = remove_cvref_t<invoke_result_t<_Func, _Err&&>>; - static_assert(__is_std_expected<_Gp>::value, - "The result of f(std::move(error())) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Gp::value_type, _Tp>, - "The result of f(std::move(error())) must have the same value_type as this expected"); - if (has_value()) { - return _Gp(); - } - return std::invoke(std::forward<_Func>(__f), std::move(error())); - } - - template <class _Func> - _LIBCPP_HIDE_FROM_ABI constexpr auto or_else(_Func&& __f) const&& { - using _Gp = remove_cvref_t<invoke_result_t<_Func, const _Err&&>>; - static_assert(__is_std_expected<_Gp>::value, - "The result of f(std::move(error())) must be a specialization of std::expected"); - static_assert(is_same_v<typename _Gp::value_type, _Tp>, - "The result of f(std::move(error())) must have the same value_type as this expected"); - if (has_value()) { - return _Gp(); - } - return std::invoke(std::forward<_Func>(__f), std::move(error())); - } - - template <class _Func> - requires is_constructible_v<_Err, _Err&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) & { - using _Up = remove_cv_t<invoke_result_t<_Func>>; - if (!has_value()) { - return expected<_Up, _Err>(unexpect, error()); - } - if constexpr (!is_void_v<_Up>) { - return expected<_Up, _Err>(__expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f)); - } else { - std::invoke(std::forward<_Func>(__f)); - return expected<_Up, _Err>(); - } - } - - template <class _Func> - requires is_constructible_v<_Err, const _Err&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) const& { - using _Up = remove_cv_t<invoke_result_t<_Func>>; - if (!has_value()) { - return expected<_Up, _Err>(unexpect, error()); - } - if constexpr (!is_void_v<_Up>) { - return expected<_Up, _Err>(__expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f)); - } else { - std::invoke(std::forward<_Func>(__f)); - return expected<_Up, _Err>(); - } - } - - template <class _Func> - requires is_constructible_v<_Err, _Err&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) && { - using _Up = remove_cv_t<invoke_result_t<_Func>>; - if (!has_value()) { - return expected<_Up, _Err>(unexpect, std::move(error())); - } - if constexpr (!is_void_v<_Up>) { - return expected<_Up, _Err>(__expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f)); - } else { - std::invoke(std::forward<_Func>(__f)); - return expected<_Up, _Err>(); - } - } - - template <class _Func> - requires is_constructible_v<_Err, const _Err&&> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) const&& { - using _Up = remove_cv_t<invoke_result_t<_Func>>; - if (!has_value()) { - return expected<_Up, _Err>(unexpect, std::move(error())); - } - if constexpr (!is_void_v<_Up>) { - return expected<_Up, _Err>(__expected_construct_in_place_from_invoke_tag{}, std::forward<_Func>(__f)); - } else { - std::invoke(std::forward<_Func>(__f)); - return expected<_Up, _Err>(); - } - } - - template <class _Func> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform_error(_Func&& __f) & { - using _Gp = remove_cv_t<invoke_result_t<_Func, _Err&>>; - static_assert(__valid_std_unexpected<_Gp>::value, - "The result of f(error()) must be a valid template argument for unexpected"); - if (has_value()) { - return expected<_Tp, _Gp>(); - } - return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error()); - } - - template <class _Func> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform_error(_Func&& __f) const& { - using _Gp = remove_cv_t<invoke_result_t<_Func, const _Err&>>; - static_assert(__valid_std_unexpected<_Gp>::value, - "The result of f(error()) must be a valid template argument for unexpected"); - if (has_value()) { - return expected<_Tp, _Gp>(); - } - return expected<_Tp, _Gp>(__expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), error()); - } - - template <class _Func> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform_error(_Func&& __f) && { - using _Gp = remove_cv_t<invoke_result_t<_Func, _Err&&>>; - static_assert(__valid_std_unexpected<_Gp>::value, - "The result of f(std::move(error())) must be a valid template argument for unexpected"); - if (has_value()) { - return expected<_Tp, _Gp>(); - } - return expected<_Tp, _Gp>( - __expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error())); - } - - template <class _Func> - _LIBCPP_HIDE_FROM_ABI constexpr auto transform_error(_Func&& __f) const&& { - using _Gp = remove_cv_t<invoke_result_t<_Func, const _Err&&>>; - static_assert(__valid_std_unexpected<_Gp>::value, - "The result of f(std::move(error())) must be a valid template argument for unexpected"); - if (has_value()) { - return expected<_Tp, _Gp>(); - } - return expected<_Tp, _Gp>( - __expected_construct_unexpected_from_invoke_tag{}, std::forward<_Func>(__f), std::move(error())); - } - // [expected.void.eq], equality operators template <class _T2, class _E2> requires is_void_v<_T2> @@ -1489,55 +947,23 @@ public: private: struct __empty_t {}; - - template <class _ErrorType> - union __union_t { + // use named union because [[no_unique_address]] cannot be applied to an unnamed union + _LIBCPP_NO_UNIQUE_ADDRESS union __union_t { _LIBCPP_HIDE_FROM_ABI constexpr __union_t() : __empty_() {} - template <class _Func, class... _Args> - _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t( - __expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args) - : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {} - - _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() - requires(is_trivially_destructible_v<_ErrorType>) - = default; - - // the expected's destructor handles this - _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() {} - - __empty_t __empty_; - _ErrorType __unex_; - }; - - // use named union because [[no_unique_address]] cannot be applied to an unnamed union, - // also guaranteed elision into a potentially-overlapping subobject is unsettled (and - // it's not clear that it's implementable, given that the function is allowed to clobber - // the tail padding) - see https://github.com/itanium-cxx-abi/cxx-abi/issues/107. - template <class _ErrorType> - requires is_trivially_move_constructible_v<_ErrorType> - union __union_t<_ErrorType> { - _LIBCPP_HIDE_FROM_ABI constexpr __union_t() : __empty_() {} - - template <class _Func, class... _Args> - _LIBCPP_HIDE_FROM_ABI constexpr explicit __union_t( - __expected_construct_unexpected_from_invoke_tag, _Func&& __f, _Args&&... __args) - : __unex_(std::invoke(std::forward<_Func>(__f), std::forward<_Args>(__args)...)) {} - _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() - requires(is_trivially_destructible_v<_ErrorType>) + requires(is_trivially_destructible_v<_Err>) = default; // the expected's destructor handles this _LIBCPP_HIDE_FROM_ABI constexpr ~__union_t() - requires(!is_trivially_destructible_v<_ErrorType>) + requires(!is_trivially_destructible_v<_Err>) {} _LIBCPP_NO_UNIQUE_ADDRESS __empty_t __empty_; - _LIBCPP_NO_UNIQUE_ADDRESS _ErrorType __unex_; - }; + _LIBCPP_NO_UNIQUE_ADDRESS _Err __unex_; + } __union_; - _LIBCPP_NO_UNIQUE_ADDRESS __union_t<_Err> __union_; bool __has_val_; }; |