| // -*- C++ -*- |
| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| #ifndef _LIBCPP___EXPECTED_UNEXPECTED_H |
| #define _LIBCPP___EXPECTED_UNEXPECTED_H |
| |
| #include <__config> |
| #include <__type_traits/conjunction.h> |
| #include <__type_traits/is_array.h> |
| #include <__type_traits/is_const.h> |
| #include <__type_traits/is_constructible.h> |
| #include <__type_traits/is_nothrow_constructible.h> |
| #include <__type_traits/is_object.h> |
| #include <__type_traits/is_same.h> |
| #include <__type_traits/is_swappable.h> |
| #include <__type_traits/is_volatile.h> |
| #include <__type_traits/negation.h> |
| #include <__type_traits/remove_cvref.h> |
| #include <__utility/forward.h> |
| #include <__utility/in_place.h> |
| #include <__utility/move.h> |
| #include <__utility/swap.h> |
| #include <initializer_list> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| #if _LIBCPP_STD_VER >= 23 |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template <class _Err> |
| class unexpected; |
| |
| template <class _Tp> |
| struct __is_std_unexpected : false_type {}; |
| |
| template <class _Err> |
| struct __is_std_unexpected<unexpected<_Err>> : true_type {}; |
| |
| template <class _Tp> |
| using __valid_std_unexpected = _BoolConstant< // |
| is_object_v<_Tp> && // |
| !is_array_v<_Tp> && // |
| !__is_std_unexpected<_Tp>::value && // |
| !is_const_v<_Tp> && // |
| !is_volatile_v<_Tp> // |
| >; |
| |
| template <class _Err> |
| class unexpected { |
| static_assert(__valid_std_unexpected<_Err>::value, |
| "[expected.un.general] states a program that instantiates std::unexpected for a non-object type, an " |
| "array type, a specialization of unexpected, or a cv-qualified type is ill-formed."); |
| |
| public: |
| _LIBCPP_HIDE_FROM_ABI constexpr unexpected(const unexpected&) = default; |
| _LIBCPP_HIDE_FROM_ABI constexpr unexpected(unexpected&&) = default; |
| |
| template <class _Error = _Err> |
| requires(!is_same_v<remove_cvref_t<_Error>, unexpected> && // |
| !is_same_v<remove_cvref_t<_Error>, in_place_t> && // |
| is_constructible_v<_Err, _Error>) |
| _LIBCPP_HIDE_FROM_ABI constexpr explicit unexpected(_Error&& __error) // |
| noexcept(is_nothrow_constructible_v<_Err, _Error>) // strengthened |
| : __unex_(std::forward<_Error>(__error)) {} |
| |
| template <class... _Args> |
| requires is_constructible_v<_Err, _Args...> |
| _LIBCPP_HIDE_FROM_ABI constexpr explicit unexpected(in_place_t, _Args&&... __args) // |
| noexcept(is_nothrow_constructible_v<_Err, _Args...>) // strengthened |
| : __unex_(std::forward<_Args>(__args)...) {} |
| |
| template <class _Up, class... _Args> |
| requires is_constructible_v<_Err, initializer_list<_Up>&, _Args...> |
| _LIBCPP_HIDE_FROM_ABI constexpr explicit unexpected(in_place_t, initializer_list<_Up> __il, _Args&&... __args) // |
| noexcept(is_nothrow_constructible_v<_Err, initializer_list<_Up>&, _Args...>) // strengthened |
| : __unex_(__il, std::forward<_Args>(__args)...) {} |
| |
| _LIBCPP_HIDE_FROM_ABI constexpr unexpected& operator=(const unexpected&) = default; |
| _LIBCPP_HIDE_FROM_ABI constexpr unexpected& operator=(unexpected&&) = default; |
| |
| _LIBCPP_HIDE_FROM_ABI constexpr const _Err& error() const& noexcept { return __unex_; } |
| _LIBCPP_HIDE_FROM_ABI constexpr _Err& error() & noexcept { return __unex_; } |
| _LIBCPP_HIDE_FROM_ABI constexpr const _Err&& error() const&& noexcept { return std::move(__unex_); } |
| _LIBCPP_HIDE_FROM_ABI constexpr _Err&& error() && noexcept { return std::move(__unex_); } |
| |
| _LIBCPP_HIDE_FROM_ABI constexpr void swap(unexpected& __other) noexcept(is_nothrow_swappable_v<_Err>) { |
| static_assert(is_swappable_v<_Err>, "unexpected::swap requires is_swappable_v<E> to be true"); |
| using std::swap; |
| swap(__unex_, __other.__unex_); |
| } |
| |
| _LIBCPP_HIDE_FROM_ABI friend constexpr void swap(unexpected& __x, unexpected& __y) noexcept(noexcept(__x.swap(__y))) |
| requires is_swappable_v<_Err> |
| { |
| __x.swap(__y); |
| } |
| |
| template <class _Err2> |
| _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const unexpected& __x, const unexpected<_Err2>& __y) { |
| return __x.__unex_ == __y.__unex_; |
| } |
| |
| private: |
| _Err __unex_; |
| }; |
| |
| template <class _Err> |
| unexpected(_Err) -> unexpected<_Err>; |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP_STD_VER >= 23 |
| |
| #endif // _LIBCPP___EXPECTED_UNEXPECTED_H |