Christopher Di Bella d10dc5a06f
[libc++] Remove dedicated namespaces for ranges functions (#76543)
We originally put implementation-detail function objects into individual
namespaces for `std::ranges` without a good reason for doing so. This
practice was continued, presumably because there was prior art. Since
there's no reason to keep these namespaces, this commit removes them,
which will slightly impact binary size.

This commit does not apply to CPOs, some of which need additional work.
2024-08-01 08:54:06 -04:00

78 lines
2.1 KiB
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___ALGORITHM_RANGES_REVERSE_H
#define _LIBCPP___ALGORITHM_RANGES_REVERSE_H
#include <__config>
#include <__iterator/concepts.h>
#include <__iterator/iter_swap.h>
#include <__iterator/next.h>
#include <__iterator/permutable.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>
#include <__ranges/dangling.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
#if _LIBCPP_STD_VER >= 20
_LIBCPP_BEGIN_NAMESPACE_STD
namespace ranges {
struct __reverse {
template <bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent>
requires permutable<_Iter>
_LIBCPP_HIDE_FROM_ABI constexpr _Iter operator()(_Iter __first, _Sent __last) const {
if constexpr (random_access_iterator<_Iter>) {
if (__first == __last)
return __first;
auto __end = ranges::next(__first, __last);
auto __ret = __end;
while (__first < --__end) {
ranges::iter_swap(__first, __end);
++__first;
}
return __ret;
} else {
auto __end = ranges::next(__first, __last);
auto __ret = __end;
while (__first != __end) {
if (__first == --__end)
break;
ranges::iter_swap(__first, __end);
++__first;
}
return __ret;
}
}
template <bidirectional_range _Range>
requires permutable<iterator_t<_Range>>
_LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Range> operator()(_Range&& __range) const {
return (*this)(ranges::begin(__range), ranges::end(__range));
}
};
inline namespace __cpo {
inline constexpr auto reverse = __reverse{};
} // namespace __cpo
} // namespace ranges
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_STD_VER >= 20
#endif // _LIBCPP___ALGORITHM_RANGES_REVERSE_H