owning_view.h 3.3 KB

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  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_OWNING_VIEW_H
  10. #define _LIBCPP___RANGES_OWNING_VIEW_H
  11. #include <__concepts/constructible.h>
  12. #include <__concepts/movable.h>
  13. #include <__config>
  14. #include <__ranges/access.h>
  15. #include <__ranges/concepts.h>
  16. #include <__ranges/data.h>
  17. #include <__ranges/empty.h>
  18. #include <__ranges/enable_borrowed_range.h>
  19. #include <__ranges/size.h>
  20. #include <__ranges/view_interface.h>
  21. #include <__type_traits/remove_cvref.h>
  22. #include <__utility/move.h>
  23. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  24. # pragma GCC system_header
  25. #endif
  26. _LIBCPP_PUSH_MACROS
  27. #include <__undef_macros>
  28. _LIBCPP_BEGIN_NAMESPACE_STD
  29. #if _LIBCPP_STD_VER >= 20
  30. namespace ranges {
  31. template <range _Rp>
  32. requires movable<_Rp> && (!__is_std_initializer_list<remove_cvref_t<_Rp>>)
  33. class owning_view : public view_interface<owning_view<_Rp>> {
  34. _Rp __r_ = _Rp();
  35. public:
  36. _LIBCPP_HIDE_FROM_ABI owning_view()
  37. requires default_initializable<_Rp>
  38. = default;
  39. _LIBCPP_HIDE_FROM_ABI constexpr owning_view(_Rp&& __r) : __r_(std::move(__r)) {}
  40. _LIBCPP_HIDE_FROM_ABI owning_view(owning_view&&) = default;
  41. _LIBCPP_HIDE_FROM_ABI owning_view& operator=(owning_view&&) = default;
  42. _LIBCPP_HIDE_FROM_ABI constexpr _Rp& base() & noexcept { return __r_; }
  43. _LIBCPP_HIDE_FROM_ABI constexpr const _Rp& base() const& noexcept { return __r_; }
  44. _LIBCPP_HIDE_FROM_ABI constexpr _Rp&& base() && noexcept { return std::move(__r_); }
  45. _LIBCPP_HIDE_FROM_ABI constexpr const _Rp&& base() const&& noexcept { return std::move(__r_); }
  46. _LIBCPP_HIDE_FROM_ABI constexpr iterator_t<_Rp> begin() { return ranges::begin(__r_); }
  47. _LIBCPP_HIDE_FROM_ABI constexpr sentinel_t<_Rp> end() { return ranges::end(__r_); }
  48. _LIBCPP_HIDE_FROM_ABI constexpr auto begin() const
  49. requires range<const _Rp>
  50. {
  51. return ranges::begin(__r_);
  52. }
  53. _LIBCPP_HIDE_FROM_ABI constexpr auto end() const
  54. requires range<const _Rp>
  55. {
  56. return ranges::end(__r_);
  57. }
  58. _LIBCPP_HIDE_FROM_ABI constexpr bool empty()
  59. requires requires { ranges::empty(__r_); }
  60. {
  61. return ranges::empty(__r_);
  62. }
  63. _LIBCPP_HIDE_FROM_ABI constexpr bool empty() const
  64. requires requires { ranges::empty(__r_); }
  65. {
  66. return ranges::empty(__r_);
  67. }
  68. _LIBCPP_HIDE_FROM_ABI constexpr auto size()
  69. requires sized_range<_Rp>
  70. {
  71. return ranges::size(__r_);
  72. }
  73. _LIBCPP_HIDE_FROM_ABI constexpr auto size() const
  74. requires sized_range<const _Rp>
  75. {
  76. return ranges::size(__r_);
  77. }
  78. _LIBCPP_HIDE_FROM_ABI constexpr auto data()
  79. requires contiguous_range<_Rp>
  80. {
  81. return ranges::data(__r_);
  82. }
  83. _LIBCPP_HIDE_FROM_ABI constexpr auto data() const
  84. requires contiguous_range<const _Rp>
  85. {
  86. return ranges::data(__r_);
  87. }
  88. };
  89. _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(owning_view);
  90. template <class _Tp>
  91. inline constexpr bool enable_borrowed_range<owning_view<_Tp>> = enable_borrowed_range<_Tp>;
  92. } // namespace ranges
  93. #endif // _LIBCPP_STD_VER >= 20
  94. _LIBCPP_END_NAMESPACE_STD
  95. _LIBCPP_POP_MACROS
  96. #endif // _LIBCPP___RANGES_OWNING_VIEW_H