v1/__memory/ranges_construct_at.h

0001 // -*- C++ -*-
0002 //===----------------------------------------------------------------------===//
0003 //
0004 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0005 // See https://llvm.org/LICENSE.txt for license information.
0006 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0007 //
0008 //===----------------------------------------------------------------------===//
0009
0010 #ifndef _LIBCPP___MEMORY_RANGES_CONSTRUCT_AT_H
0011 #define _LIBCPP___MEMORY_RANGES_CONSTRUCT_AT_H
0012
0013 #include <__concepts/destructible.h>
0014 #include <__config>
0015 #include <__iterator/incrementable_traits.h>
0016 #include <__iterator/iterator_traits.h>
0017 #include <__memory/concepts.h>
0018 #include <__memory/construct_at.h>
0019 #include <__ranges/access.h>
0020 #include <__ranges/concepts.h>
0021 #include <__ranges/dangling.h>
0022 #include <__utility/declval.h>
0023 #include <__utility/forward.h>
0024 #include <__utility/move.h>
0025
0026 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0027 #  pragma GCC system_header
0028 #endif
0029
0030 _LIBCPP_PUSH_MACROS
0031 #include <__undef_macros>
0032
0033 _LIBCPP_BEGIN_NAMESPACE_STD
0034
0035 #if _LIBCPP_STD_VER >= 20
0036 namespace ranges {
0037
0038 // construct_at
0039
0040 struct __construct_at {
0041   template <class _Tp, class... _Args, class = decltype(::new(std::declval<void*>()) _Tp(std::declval<_Args>()...))>
0042   _LIBCPP_HIDE_FROM_ABI constexpr _Tp* operator()(_Tp* __location, _Args&&... __args) const {
0043     return std::construct_at(__location, std::forward<_Args>(__args)...);
0044   }
0045 };
0046
0047 inline namespace __cpo {
0048 inline constexpr auto construct_at = __construct_at{};
0049 } // namespace __cpo
0050
0051 // destroy_at
0052
0053 struct __destroy_at {
0054   template <destructible _Tp>
0055   _LIBCPP_HIDE_FROM_ABI constexpr void operator()(_Tp* __location) const noexcept {
0056     std::destroy_at(__location);
0057   }
0058 };
0059
0060 inline namespace __cpo {
0061 inline constexpr auto destroy_at = __destroy_at{};
0062 } // namespace __cpo
0063
0064 // destroy
0065
0066 struct __destroy {
0067   template <__nothrow_input_iterator _InputIterator, __nothrow_sentinel_for<_InputIterator> _Sentinel>
0068     requires destructible<iter_value_t<_InputIterator>>
0069   _LIBCPP_HIDE_FROM_ABI constexpr _InputIterator operator()(_InputIterator __first, _Sentinel __last) const noexcept {
0070     return std::__destroy(std::move(__first), std::move(__last));
0071   }
0072
0073   template <__nothrow_input_range _InputRange>
0074     requires destructible<range_value_t<_InputRange>>
0075   _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_InputRange> operator()(_InputRange&& __range) const noexcept {
0076     return (*this)(ranges::begin(__range), ranges::end(__range));
0077   }
0078 };
0079
0080 inline namespace __cpo {
0081 inline constexpr auto destroy = __destroy{};
0082 } // namespace __cpo
0083
0084 // destroy_n
0085
0086 struct __destroy_n {
0087   template <__nothrow_input_iterator _InputIterator>
0088     requires destructible<iter_value_t<_InputIterator>>
0089   _LIBCPP_HIDE_FROM_ABI constexpr _InputIterator
0090   operator()(_InputIterator __first, iter_difference_t<_InputIterator> __n) const noexcept {
0091     return std::destroy_n(std::move(__first), __n);
0092   }
0093 };
0094
0095 inline namespace __cpo {
0096 inline constexpr auto destroy_n = __destroy_n{};
0097 } // namespace __cpo
0098
0099 } // namespace ranges
0100
0101 #endif // _LIBCPP_STD_VER >= 20
0102
0103 _LIBCPP_END_NAMESPACE_STD
0104
0105 _LIBCPP_POP_MACROS
0106
0107 #endif // _LIBCPP___MEMORY_RANGES_CONSTRUCT_AT_H