libcxx/include/__memory/ranges_construct_at.h

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef _LIBCPP___MEMORY_RANGES_CONSTRUCT_AT_H
  11 #define _LIBCPP___MEMORY_RANGES_CONSTRUCT_AT_H
  12
  13 #include <__concepts/destructible.h>
  14 #include <__config>
  15 #include <__iterator/incrementable_traits.h>
  16 #include <__iterator/iterator_traits.h>
  17 #include <__memory/concepts.h>
  18 #include <__memory/construct_at.h>
  19 #include <__ranges/access.h>
  20 #include <__ranges/concepts.h>
  21 #include <__ranges/dangling.h>
  22 #include <__utility/declval.h>
  23 #include <__utility/forward.h>
  24 #include <__utility/move.h>
  25 #include <new>
  26
  27 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  28 #  pragma GCC system_header
  29 #endif
  30
  31 _LIBCPP_PUSH_MACROS
  32 #include <__undef_macros>
  33
  34 _LIBCPP_BEGIN_NAMESPACE_STD
  35
  36 #if _LIBCPP_STD_VER >= 20
  37 namespace ranges {
  38
  39 // construct_at
  40
  41 struct __construct_at {
  42   template <class _Tp, class... _Args, class = decltype(::new(std::declval<void*>()) _Tp(std::declval<_Args>()...))>
  43   _LIBCPP_HIDE_FROM_ABI constexpr _Tp* operator()(_Tp* __location, _Args&&... __args) const {
  44     return std::construct_at(__location, std::forward<_Args>(__args)...);
  45   }
  46 };
  47
  48 inline namespace __cpo {
  49 inline constexpr auto construct_at = __construct_at{};
  50 } // namespace __cpo
  51
  52 // destroy_at
  53
  54 struct __destroy_at {
  55   template <destructible _Tp>
  56   _LIBCPP_HIDE_FROM_ABI constexpr void operator()(_Tp* __location) const noexcept {
  57     std::destroy_at(__location);
  58   }
  59 };
  60
  61 inline namespace __cpo {
  62 inline constexpr auto destroy_at = __destroy_at{};
  63 } // namespace __cpo
  64
  65 // destroy
  66
  67 struct __destroy {
  68   template <__nothrow_input_iterator _InputIterator, __nothrow_sentinel_for<_InputIterator> _Sentinel>
  69     requires destructible<iter_value_t<_InputIterator>>
  70   _LIBCPP_HIDE_FROM_ABI constexpr _InputIterator operator()(_InputIterator __first, _Sentinel __last) const noexcept {
  71     return std::__destroy(std::move(__first), std::move(__last));
  72   }
  73
  74   template <__nothrow_input_range _InputRange>
  75     requires destructible<range_value_t<_InputRange>>
  76   _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_InputRange> operator()(_InputRange&& __range) const noexcept {
  77     return (*this)(ranges::begin(__range), ranges::end(__range));
  78   }
  79 };
  80
  81 inline namespace __cpo {
  82 inline constexpr auto destroy = __destroy{};
  83 } // namespace __cpo
  84
  85 // destroy_n
  86
  87 struct __destroy_n {
  88   template <__nothrow_input_iterator _InputIterator>
  89     requires destructible<iter_value_t<_InputIterator>>
  90   _LIBCPP_HIDE_FROM_ABI constexpr _InputIterator
  91   operator()(_InputIterator __first, iter_difference_t<_InputIterator> __n) const noexcept {
  92     return std::destroy_n(std::move(__first), __n);
  93   }
  94 };
  95
  96 inline namespace __cpo {
  97 inline constexpr auto destroy_n = __destroy_n{};
  98 } // namespace __cpo
  99
 100 } // namespace ranges
 101
 102 #endif // _LIBCPP_STD_VER >= 20
 103
 104 _LIBCPP_END_NAMESPACE_STD
 105
 106 _LIBCPP_POP_MACROS
 107
 108 #endif // _LIBCPP___MEMORY_RANGES_CONSTRUCT_AT_H