c48be319db
This allows us to make use of any optimizations to `std::swap_ranges` in `ranges::swap_ranges`. This patch also moves some code specific to `ranges::swap_ranges` into `ranges_swap_ranges.h`.
96 lines
3.4 KiB
C++
96 lines
3.4 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_SWAP_RANGES_H
|
|
#define _LIBCPP___ALGORITHM_RANGES_SWAP_RANGES_H
|
|
|
|
#include <__algorithm/in_in_result.h>
|
|
#include <__algorithm/iterator_operations.h>
|
|
#include <__algorithm/min.h>
|
|
#include <__algorithm/swap_ranges.h>
|
|
#include <__config>
|
|
#include <__iterator/concepts.h>
|
|
#include <__iterator/iter_swap.h>
|
|
#include <__ranges/access.h>
|
|
#include <__ranges/concepts.h>
|
|
#include <__ranges/dangling.h>
|
|
#include <__type_traits/is_same.h>
|
|
#include <__utility/move.h>
|
|
#include <__utility/pair.h>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_PUSH_MACROS
|
|
#include <__undef_macros>
|
|
|
|
#if _LIBCPP_STD_VER >= 20
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
namespace ranges {
|
|
|
|
template <class _I1, class _I2>
|
|
using swap_ranges_result = in_in_result<_I1, _I2>;
|
|
|
|
struct __swap_ranges {
|
|
template <input_iterator _I1, sentinel_for<_I1> _S1, input_iterator _I2, sentinel_for<_I2> _S2>
|
|
requires indirectly_swappable<_I1, _I2>
|
|
_LIBCPP_HIDE_FROM_ABI constexpr swap_ranges_result<_I1, _I2>
|
|
operator()(_I1 __first1, _S1 __last1, _I2 __first2, _S2 __last2) const {
|
|
if constexpr (sized_sentinel_for<_I1, _S1> && sized_sentinel_for<_I2, _S2> &&
|
|
(random_access_iterator<_I1> || random_access_iterator<_I2> ||
|
|
(is_same_v<_I1, _S1> && is_same_v<_I2, _S2>))) {
|
|
auto __offset = std::min(__last1 - __first1, __last2 - __first2);
|
|
|
|
auto __ret = [&] {
|
|
if constexpr (random_access_iterator<_I1>)
|
|
return std::__swap_ranges<_RangeAlgPolicy>(__first1, __first1 + __offset, std::move(__first2));
|
|
else if constexpr (random_access_iterator<_I2>)
|
|
return std::__swap_ranges<_RangeAlgPolicy>(__first2, __first2 + __offset, std::move(__first1));
|
|
else if (__last2 - __first2 < __last1 - __first1) {
|
|
auto __reversed =
|
|
std::__swap_ranges<_RangeAlgPolicy>(std::move(__first2), std::move(__last2), std::move(__first1));
|
|
return std::pair<_I1, _I2>(std::move(__reversed.second), std::move(__reversed.first));
|
|
} else
|
|
return std::__swap_ranges<_RangeAlgPolicy>(std::move(__first1), std::move(__last1), std::move(__first2));
|
|
}();
|
|
return {std::move(__ret.first), std::move(__ret.second)};
|
|
} else {
|
|
while (__first1 != __last1 && __first2 != __last2) {
|
|
ranges::iter_swap(__first1, __first2);
|
|
++__first1;
|
|
++__first2;
|
|
}
|
|
|
|
return {std::move(__first1), std::move(__first2)};
|
|
}
|
|
}
|
|
|
|
template <input_range _R1, input_range _R2>
|
|
requires indirectly_swappable<iterator_t<_R1>, iterator_t<_R2>>
|
|
_LIBCPP_HIDE_FROM_ABI constexpr swap_ranges_result<borrowed_iterator_t<_R1>, borrowed_iterator_t<_R2>>
|
|
operator()(_R1&& __r1, _R2&& __r2) const {
|
|
return operator()(ranges::begin(__r1), ranges::end(__r1), ranges::begin(__r2), ranges::end(__r2));
|
|
}
|
|
};
|
|
|
|
inline namespace __cpo {
|
|
inline constexpr auto swap_ranges = __swap_ranges{};
|
|
} // namespace __cpo
|
|
} // namespace ranges
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
#endif // _LIBCPP_STD_VER >= 20
|
|
|
|
_LIBCPP_POP_MACROS
|
|
|
|
#endif // _LIBCPP___ALGORITHM_RANGES_SWAP_RANGES_H
|