| // -*- 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___ITERATOR_ITER_MOVE_H |
| #define _LIBCPP___ITERATOR_ITER_MOVE_H |
| |
| #include <__concepts/class_or_enum.h> |
| #include <__config> |
| #include <__iterator/iterator_traits.h> |
| #include <__utility/forward.h> |
| #include <__utility/move.h> |
| #include <type_traits> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if _LIBCPP_STD_VER > 17 |
| |
| // [iterator.cust.move] |
| |
| namespace ranges { |
| namespace __iter_move { |
| |
| void iter_move(); |
| |
| template <class _Tp> |
| concept __unqualified_iter_move = |
| __class_or_enum<remove_cvref_t<_Tp>> && |
| requires (_Tp&& __t) { |
| iter_move(std::forward<_Tp>(__t)); |
| }; |
| |
| template<class _Tp> |
| concept __move_deref = |
| !__unqualified_iter_move<_Tp> && |
| requires (_Tp&& __t) { |
| *__t; |
| requires is_lvalue_reference_v<decltype(*__t)>; |
| }; |
| |
| template<class _Tp> |
| concept __just_deref = |
| !__unqualified_iter_move<_Tp> && |
| !__move_deref<_Tp> && |
| requires (_Tp&& __t) { |
| *__t; |
| requires (!is_lvalue_reference_v<decltype(*__t)>); |
| }; |
| |
| // [iterator.cust.move] |
| |
| struct __fn { |
| template<class _Ip> |
| requires __unqualified_iter_move<_Ip> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) operator()(_Ip&& __i) const |
| noexcept(noexcept(iter_move(std::forward<_Ip>(__i)))) |
| { |
| return iter_move(std::forward<_Ip>(__i)); |
| } |
| |
| template<class _Ip> |
| requires __move_deref<_Ip> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Ip&& __i) const |
| noexcept(noexcept(std::move(*std::forward<_Ip>(__i)))) |
| -> decltype( std::move(*std::forward<_Ip>(__i))) |
| { return std::move(*std::forward<_Ip>(__i)); } |
| |
| template<class _Ip> |
| requires __just_deref<_Ip> |
| [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Ip&& __i) const |
| noexcept(noexcept(*std::forward<_Ip>(__i))) |
| -> decltype( *std::forward<_Ip>(__i)) |
| { return *std::forward<_Ip>(__i); } |
| }; |
| } // namespace __iter_move |
| |
| inline namespace __cpo { |
| inline constexpr auto iter_move = __iter_move::__fn{}; |
| } // namespace __cpo |
| } // namespace ranges |
| |
| template<__dereferenceable _Tp> |
| requires requires(_Tp& __t) { { ranges::iter_move(__t) } -> __can_reference; } |
| using iter_rvalue_reference_t = decltype(ranges::iter_move(declval<_Tp&>())); |
| |
| #endif // _LIBCPP_STD_VER > 17 |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___ITERATOR_ITER_MOVE_H |