xref: /freebsd-src/contrib/llvm-project/libcxx/include/__algorithm/ranges_swap_ranges.h (revision fcaf7f8644a9988098ac6be2165bce3ea4786e91)
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef _LIBCPP___ALGORITHM_RANGES_SWAP_RANGES_H
10 #define _LIBCPP___ALGORITHM_RANGES_SWAP_RANGES_H
11 
12 #include <__algorithm/in_in_result.h>
13 #include <__config>
14 #include <__iterator/concepts.h>
15 #include <__iterator/iter_swap.h>
16 #include <__ranges/access.h>
17 #include <__ranges/concepts.h>
18 #include <__ranges/dangling.h>
19 #include <__utility/move.h>
20 
21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22 #  pragma GCC system_header
23 #endif
24 
25 #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
26 
27 _LIBCPP_BEGIN_NAMESPACE_STD
28 
29 namespace ranges {
30 
31 template <class _I1, class _I2>
32 using swap_ranges_result = in_in_result<_I1, _I2>;
33 
34 namespace __swap_ranges {
35 struct __fn {
36   template <input_iterator _I1, sentinel_for<_I1> _S1,
37             input_iterator _I2, sentinel_for<_I2> _S2>
38     requires indirectly_swappable<_I1, _I2>
39   _LIBCPP_HIDE_FROM_ABI constexpr swap_ranges_result<_I1, _I2>
40   operator()(_I1 __first1, _S1 __last1, _I2 __first2, _S2 __last2) const {
41     while (__first1 != __last1 && __first2 != __last2) {
42       ranges::iter_swap(__first1, __first2);
43       ++__first1;
44       ++__first2;
45     }
46     return {_VSTD::move(__first1), _VSTD::move(__first2)};
47   }
48 
49   template <input_range _R1, input_range _R2>
50     requires indirectly_swappable<iterator_t<_R1>, iterator_t<_R2>>
51   _LIBCPP_HIDE_FROM_ABI constexpr
52   swap_ranges_result<borrowed_iterator_t<_R1>, borrowed_iterator_t<_R2>>
53   operator()(_R1&& __r1, _R2&& __r2) const {
54     return operator()(ranges::begin(__r1), ranges::end(__r1),
55                       ranges::begin(__r2), ranges::end(__r2));
56   }
57 };
58 } // namespace __swap_ranges
59 
60 inline namespace __cpo {
61   inline constexpr auto swap_ranges = __swap_ranges::__fn{};
62 } // namespace __cpo
63 } // namespace ranges
64 
65 _LIBCPP_END_NAMESPACE_STD
66 
67 #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
68 
69 #endif // _LIBCPP___ALGORITHM_RANGES_SWAP_RANGES_H
70