ranges_sample.h 2.5 KB

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  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. #ifndef _LIBCPP___ALGORITHM_RANGES_SAMPLE_H
  9. #define _LIBCPP___ALGORITHM_RANGES_SAMPLE_H
  10. #include <__algorithm/iterator_operations.h>
  11. #include <__algorithm/sample.h>
  12. #include <__algorithm/uniform_random_bit_generator_adaptor.h>
  13. #include <__config>
  14. #include <__iterator/concepts.h>
  15. #include <__iterator/incrementable_traits.h>
  16. #include <__iterator/iterator_traits.h>
  17. #include <__random/uniform_random_bit_generator.h>
  18. #include <__ranges/access.h>
  19. #include <__ranges/concepts.h>
  20. #include <__utility/forward.h>
  21. #include <__utility/move.h>
  22. #include <type_traits>
  23. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  24. # pragma GCC system_header
  25. #endif
  26. #if _LIBCPP_STD_VER > 17
  27. _LIBCPP_BEGIN_NAMESPACE_STD
  28. namespace ranges {
  29. namespace __sample {
  30. struct __fn {
  31. template <input_iterator _Iter, sentinel_for<_Iter> _Sent, weakly_incrementable _OutIter, class _Gen>
  32. requires (forward_iterator<_Iter> || random_access_iterator<_OutIter>) &&
  33. indirectly_copyable<_Iter, _OutIter> &&
  34. uniform_random_bit_generator<remove_reference_t<_Gen>>
  35. _LIBCPP_HIDE_FROM_ABI
  36. _OutIter operator()(_Iter __first, _Sent __last,
  37. _OutIter __out_first, iter_difference_t<_Iter> __n, _Gen&& __gen) const {
  38. _ClassicGenAdaptor<_Gen> __adapted_gen(__gen);
  39. return std::__sample<_RangeAlgPolicy>(
  40. std::move(__first), std::move(__last), std::move(__out_first), __n, __adapted_gen);
  41. }
  42. template <input_range _Range, weakly_incrementable _OutIter, class _Gen>
  43. requires (forward_range<_Range> || random_access_iterator<_OutIter>) &&
  44. indirectly_copyable<iterator_t<_Range>, _OutIter> &&
  45. uniform_random_bit_generator<remove_reference_t<_Gen>>
  46. _LIBCPP_HIDE_FROM_ABI
  47. _OutIter operator()(_Range&& __range, _OutIter __out_first, range_difference_t<_Range> __n, _Gen&& __gen) const {
  48. return (*this)(ranges::begin(__range), ranges::end(__range),
  49. std::move(__out_first), __n, std::forward<_Gen>(__gen));
  50. }
  51. };
  52. } // namespace __sample
  53. inline namespace __cpo {
  54. inline constexpr auto sample = __sample::__fn{};
  55. } // namespace __cpo
  56. } // namespace ranges
  57. _LIBCPP_END_NAMESPACE_STD
  58. #endif // _LIBCPP_STD_VER > 17
  59. #endif // _LIBCPP___ALGORITHM_RANGES_SAMPLE_H