libcxx/include/__algorithm/ranges_shuffle.h

   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 <__type_traits/remove_reference.h>
  27 #include <__utility/forward.h>
  28 #include <__utility/move.h>
  29
  30 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  31 #  pragma GCC system_header
  32 #endif
  33
  34 #if _LIBCPP_STD_VER >= 20
  35
  36 _LIBCPP_BEGIN_NAMESPACE_STD
  37
  38 namespace ranges {
  39 namespace __shuffle {
  40
  41 struct __fn {
  42   template <random_access_iterator _Iter, sentinel_for<_Iter> _Sent, class _Gen>
  43     requires permutable<_Iter> && uniform_random_bit_generator<remove_reference_t<_Gen>>
  44   _LIBCPP_HIDE_FROM_ABI _Iter operator()(_Iter __first, _Sent __last, _Gen&& __gen) const {
  45     _ClassicGenAdaptor<_Gen> __adapted_gen(__gen);
  46     return std::__shuffle<_RangeAlgPolicy>(std::move(__first), std::move(__last), __adapted_gen);
  47   }
  48
  49   template <random_access_range _Range, class _Gen>
  50     requires permutable<iterator_t<_Range>> && uniform_random_bit_generator<remove_reference_t<_Gen>>
  51   _LIBCPP_HIDE_FROM_ABI borrowed_iterator_t<_Range> operator()(_Range&& __range, _Gen&& __gen) const {
  52     return (*this)(ranges::begin(__range), ranges::end(__range), std::forward<_Gen>(__gen));
  53   }
  54 };
  55
  56 } // namespace __shuffle
  57
  58 inline namespace __cpo {
  59 inline constexpr auto shuffle = __shuffle::__fn{};
  60 } // namespace __cpo
  61 } // namespace ranges
  62
  63 _LIBCPP_END_NAMESPACE_STD
  64
  65 #endif // _LIBCPP_STD_VER >= 20
  66
  67 #endif // _LIBCPP___ALGORITHM_RANGES_SHUFFLE_H