v1/__algorithm/ranges_sample.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___ALGORITHM_RANGES_SAMPLE_H
0010 #define _LIBCPP___ALGORITHM_RANGES_SAMPLE_H
0011
0012 #include <__algorithm/iterator_operations.h>
0013 #include <__algorithm/sample.h>
0014 #include <__algorithm/uniform_random_bit_generator_adaptor.h>
0015 #include <__config>
0016 #include <__iterator/concepts.h>
0017 #include <__iterator/incrementable_traits.h>
0018 #include <__iterator/iterator_traits.h>
0019 #include <__random/uniform_random_bit_generator.h>
0020 #include <__ranges/access.h>
0021 #include <__ranges/concepts.h>
0022 #include <__type_traits/remove_reference.h>
0023 #include <__utility/forward.h>
0024 #include <__utility/move.h>
0025
0026 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0027 #  pragma GCC system_header
0028 #endif
0029
0030 _LIBCPP_PUSH_MACROS
0031 #include <__undef_macros>
0032
0033 #if _LIBCPP_STD_VER >= 20
0034
0035 _LIBCPP_BEGIN_NAMESPACE_STD
0036
0037 namespace ranges {
0038 struct __sample {
0039   template <input_iterator _Iter, sentinel_for<_Iter> _Sent, weakly_incrementable _OutIter, class _Gen>
0040     requires(forward_iterator<_Iter> || random_access_iterator<_OutIter>) && indirectly_copyable<_Iter, _OutIter> &&
0041             uniform_random_bit_generator<remove_reference_t<_Gen>>
0042   _LIBCPP_HIDE_FROM_ABI _OutIter
0043   operator()(_Iter __first, _Sent __last, _OutIter __out_first, iter_difference_t<_Iter> __n, _Gen&& __gen) const {
0044     _ClassicGenAdaptor<_Gen> __adapted_gen(__gen);
0045     return std::__sample<_RangeAlgPolicy>(
0046         std::move(__first), std::move(__last), std::move(__out_first), __n, __adapted_gen);
0047   }
0048
0049   template <input_range _Range, weakly_incrementable _OutIter, class _Gen>
0050     requires(forward_range<_Range> || random_access_iterator<_OutIter>) &&
0051             indirectly_copyable<iterator_t<_Range>, _OutIter> && uniform_random_bit_generator<remove_reference_t<_Gen>>
0052   _LIBCPP_HIDE_FROM_ABI _OutIter
0053   operator()(_Range&& __range, _OutIter __out_first, range_difference_t<_Range> __n, _Gen&& __gen) const {
0054     return (*this)(
0055         ranges::begin(__range), ranges::end(__range), std::move(__out_first), __n, std::forward<_Gen>(__gen));
0056   }
0057 };
0058
0059 inline namespace __cpo {
0060 inline constexpr auto sample = __sample{};
0061 } // namespace __cpo
0062 } // namespace ranges
0063
0064 _LIBCPP_END_NAMESPACE_STD
0065
0066 #endif // _LIBCPP_STD_VER >= 20
0067
0068 _LIBCPP_POP_MACROS
0069
0070 #endif // _LIBCPP___ALGORITHM_RANGES_SAMPLE_H