llvm-project/libcxx/include/__memory/ranges_destroy.h
Louis Dionne f332455dd9
[libc++] Extract destroy algorithms into separate headers (#126449)
This patch separates the destroy algorithms from the primitive
construct_at and destroy_at operations, which are conceptually not
algorithms. This makes it easier to start using these destroy algorithms
from upcoming relocation facilities.

As part of this, it also implements `std::destroy_at` for arrays without
relying on the `std::destroy` algorithm, which is conceptually a
higher-level facility.
2025-02-10 21:19:46 +01:00

80 lines
2.3 KiB
C++

// -*- 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___MEMORY_RANGES_DESTROY_H
#define _LIBCPP___MEMORY_RANGES_DESTROY_H
#include <__concepts/destructible.h>
#include <__config>
#include <__iterator/incrementable_traits.h>
#include <__iterator/iterator_traits.h>
#include <__memory/concepts.h>
#include <__memory/destroy.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>
#include <__ranges/dangling.h>
#include <__utility/move.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 20
namespace ranges {
// destroy
struct __destroy {
template <__nothrow_input_iterator _InputIterator, __nothrow_sentinel_for<_InputIterator> _Sentinel>
requires destructible<iter_value_t<_InputIterator>>
_LIBCPP_HIDE_FROM_ABI constexpr _InputIterator operator()(_InputIterator __first, _Sentinel __last) const noexcept {
return std::__destroy(std::move(__first), std::move(__last));
}
template <__nothrow_input_range _InputRange>
requires destructible<range_value_t<_InputRange>>
_LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_InputRange> operator()(_InputRange&& __range) const noexcept {
return (*this)(ranges::begin(__range), ranges::end(__range));
}
};
inline namespace __cpo {
inline constexpr auto destroy = __destroy{};
} // namespace __cpo
// destroy_n
struct __destroy_n {
template <__nothrow_input_iterator _InputIterator>
requires destructible<iter_value_t<_InputIterator>>
_LIBCPP_HIDE_FROM_ABI constexpr _InputIterator
operator()(_InputIterator __first, iter_difference_t<_InputIterator> __n) const noexcept {
return std::destroy_n(std::move(__first), __n);
}
};
inline namespace __cpo {
inline constexpr auto destroy_n = __destroy_n{};
} // namespace __cpo
} // namespace ranges
#endif // _LIBCPP_STD_VER >= 20
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___MEMORY_RANGES_DESTROY_H