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_SHUFFLE_H
10 #define _LIBCPP___ALGORITHM_RANGES_SHUFFLE_H
11 
12 #include <__algorithm/iterator_operations.h>
13 #include <__algorithm/shuffle.h>
14 #include <__algorithm/uniform_random_bit_generator_adaptor.h>
15 #include <__config>
16 #include <__functional/invoke.h>
17 #include <__functional/ranges_operations.h>
18 #include <__iterator/concepts.h>
19 #include <__iterator/iterator_traits.h>
20 #include <__iterator/next.h>
21 #include <__iterator/permutable.h>
22 #include <__random/uniform_random_bit_generator.h>
23 #include <__ranges/access.h>
24 #include <__ranges/concepts.h>
25 #include <__ranges/dangling.h>
26 #include <__utility/forward.h>
27 #include <__utility/move.h>
28 #include <type_traits>
29 
30 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
31 #  pragma GCC system_header
32 #endif
33 
34 #if _LIBCPP_STD_VER > 17
35 
36 _LIBCPP_BEGIN_NAMESPACE_STD
37 
38 namespace ranges {
39 namespace __shuffle {
40 
41 struct __fn {
42 
43   template <random_access_iterator _Iter, sentinel_for<_Iter> _Sent, class _Gen>
44   requires permutable<_Iter> && uniform_random_bit_generator<remove_reference_t<_Gen>>
45   _LIBCPP_HIDE_FROM_ABI
46   _Iter operator()(_Iter __first, _Sent __last, _Gen&& __gen) const {
47     _ClassicGenAdaptor<_Gen> __adapted_gen(__gen);
48     return std::__shuffle<_RangeAlgPolicy>(std::move(__first), std::move(__last), __adapted_gen);
49   }
50 
51   template<random_access_range _Range, class _Gen>
52   requires permutable<iterator_t<_Range>> && uniform_random_bit_generator<remove_reference_t<_Gen>>
53   _LIBCPP_HIDE_FROM_ABI
54   borrowed_iterator_t<_Range> operator()(_Range&& __range, _Gen&& __gen) const {
55     return (*this)(ranges::begin(__range), ranges::end(__range), std::forward<_Gen>(__gen));
56   }
57 
58 };
59 
60 } // namespace __shuffle
61 
62 inline namespace __cpo {
63   inline constexpr auto shuffle = __shuffle::__fn{};
64 } // namespace __cpo
65 } // namespace ranges
66 
67 _LIBCPP_END_NAMESPACE_STD
68 
69 #endif // _LIBCPP_STD_VER > 17
70 
71 #endif // _LIBCPP___ALGORITHM_RANGES_SHUFFLE_H
72