concepts.h 4.5 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150
  1. // -*- C++ -*-
  2. //===----------------------------------------------------------------------===//
  3. //
  4. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  5. // See https://llvm.org/LICENSE.txt for license information.
  6. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  7. //
  8. //===----------------------------------------------------------------------===//
  9. #ifndef _LIBCPP___RANGES_CONCEPTS_H
  10. #define _LIBCPP___RANGES_CONCEPTS_H
  11. #include <__concepts/constructible.h>
  12. #include <__concepts/movable.h>
  13. #include <__concepts/same_as.h>
  14. #include <__config>
  15. #include <__iterator/concepts.h>
  16. #include <__iterator/incrementable_traits.h>
  17. #include <__iterator/iter_move.h>
  18. #include <__iterator/iterator_traits.h>
  19. #include <__iterator/readable_traits.h>
  20. #include <__ranges/access.h>
  21. #include <__ranges/data.h>
  22. #include <__ranges/enable_borrowed_range.h>
  23. #include <__ranges/enable_view.h>
  24. #include <__ranges/size.h>
  25. #include <__type_traits/add_pointer.h>
  26. #include <__type_traits/is_reference.h>
  27. #include <__type_traits/remove_cvref.h>
  28. #include <__type_traits/remove_reference.h>
  29. #include <__utility/declval.h>
  30. #include <initializer_list>
  31. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  32. # pragma GCC system_header
  33. #endif
  34. _LIBCPP_BEGIN_NAMESPACE_STD
  35. #if _LIBCPP_STD_VER >= 20
  36. namespace ranges {
  37. // [range.range]
  38. template <class _Tp>
  39. concept range = requires(_Tp& __t) {
  40. ranges::begin(__t); // sometimes equality-preserving
  41. ranges::end(__t);
  42. };
  43. template <class _Tp>
  44. concept input_range = range<_Tp> && input_iterator<iterator_t<_Tp>>;
  45. template<class _Range>
  46. concept borrowed_range = range<_Range> &&
  47. (is_lvalue_reference_v<_Range> || enable_borrowed_range<remove_cvref_t<_Range>>);
  48. // `iterator_t` defined in <__ranges/access.h>
  49. template <range _Rp>
  50. using sentinel_t = decltype(ranges::end(std::declval<_Rp&>()));
  51. template <range _Rp>
  52. using range_difference_t = iter_difference_t<iterator_t<_Rp>>;
  53. template <range _Rp>
  54. using range_value_t = iter_value_t<iterator_t<_Rp>>;
  55. template <range _Rp>
  56. using range_reference_t = iter_reference_t<iterator_t<_Rp>>;
  57. template <range _Rp>
  58. using range_rvalue_reference_t = iter_rvalue_reference_t<iterator_t<_Rp>>;
  59. template <range _Rp>
  60. using range_common_reference_t = iter_common_reference_t<iterator_t<_Rp>>;
  61. // [range.sized]
  62. template <class _Tp>
  63. concept sized_range = range<_Tp> && requires(_Tp& __t) { ranges::size(__t); };
  64. template<sized_range _Rp>
  65. using range_size_t = decltype(ranges::size(std::declval<_Rp&>()));
  66. // `disable_sized_range` defined in `<__ranges/size.h>`
  67. // [range.view], views
  68. // `enable_view` defined in <__ranges/enable_view.h>
  69. // `view_base` defined in <__ranges/enable_view.h>
  70. template <class _Tp>
  71. concept view =
  72. range<_Tp> &&
  73. movable<_Tp> &&
  74. enable_view<_Tp>;
  75. template <class _Range>
  76. concept __simple_view =
  77. view<_Range> && range<const _Range> &&
  78. same_as<iterator_t<_Range>, iterator_t<const _Range>> &&
  79. same_as<sentinel_t<_Range>, sentinel_t<const _Range>>;
  80. // [range.refinements], other range refinements
  81. template <class _Rp, class _Tp>
  82. concept output_range = range<_Rp> && output_iterator<iterator_t<_Rp>, _Tp>;
  83. template <class _Tp>
  84. concept forward_range = input_range<_Tp> && forward_iterator<iterator_t<_Tp>>;
  85. template <class _Tp>
  86. concept bidirectional_range = forward_range<_Tp> && bidirectional_iterator<iterator_t<_Tp>>;
  87. template <class _Tp>
  88. concept random_access_range =
  89. bidirectional_range<_Tp> && random_access_iterator<iterator_t<_Tp>>;
  90. template<class _Tp>
  91. concept contiguous_range =
  92. random_access_range<_Tp> &&
  93. contiguous_iterator<iterator_t<_Tp>> &&
  94. requires(_Tp& __t) {
  95. { ranges::data(__t) } -> same_as<add_pointer_t<range_reference_t<_Tp>>>;
  96. };
  97. template <class _Tp>
  98. concept common_range = range<_Tp> && same_as<iterator_t<_Tp>, sentinel_t<_Tp>>;
  99. template <class _Tp>
  100. inline constexpr bool __is_std_initializer_list = false;
  101. template <class _Ep>
  102. inline constexpr bool __is_std_initializer_list<initializer_list<_Ep>> = true;
  103. template <class _Tp>
  104. concept viewable_range =
  105. range<_Tp> &&
  106. ((view<remove_cvref_t<_Tp>> && constructible_from<remove_cvref_t<_Tp>, _Tp>) ||
  107. (!view<remove_cvref_t<_Tp>> &&
  108. (is_lvalue_reference_v<_Tp> ||
  109. (movable<remove_reference_t<_Tp>> && !__is_std_initializer_list<remove_cvref_t<_Tp>>))));
  110. } // namespace ranges
  111. #endif // _LIBCPP_STD_VER >= 20
  112. _LIBCPP_END_NAMESPACE_STD
  113. #endif // _LIBCPP___RANGES_CONCEPTS_H