libcxx/include/__ranges/owning_view.h

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