__cxx03/__ranges/owning_view.h

0001 // -*- C++ -*-
0002 //===----------------------------------------------------------------------===//
0003 //
0004 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0005 // See https://llvm.org/LICENSE.txt for license information.
0006 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0007 //
0008 //===----------------------------------------------------------------------===//
0009
0010 #ifndef _LIBCPP___CXX03___RANGES_OWNING_VIEW_H
0011 #define _LIBCPP___CXX03___RANGES_OWNING_VIEW_H
0012
0013 #include <__cxx03/__concepts/constructible.h>
0014 #include <__cxx03/__concepts/movable.h>
0015 #include <__cxx03/__config>
0016 #include <__cxx03/__ranges/access.h>
0017 #include <__cxx03/__ranges/concepts.h>
0018 #include <__cxx03/__ranges/data.h>
0019 #include <__cxx03/__ranges/empty.h>
0020 #include <__cxx03/__ranges/enable_borrowed_range.h>
0021 #include <__cxx03/__ranges/size.h>
0022 #include <__cxx03/__ranges/view_interface.h>
0023 #include <__cxx03/__type_traits/remove_cvref.h>
0024 #include <__cxx03/__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 <__cxx03/__undef_macros>
0032
0033 _LIBCPP_BEGIN_NAMESPACE_STD
0034
0035 #if _LIBCPP_STD_VER >= 20
0036
0037 namespace ranges {
0038 template <range _Rp>
0039   requires movable<_Rp> && (!__is_std_initializer_list<remove_cvref_t<_Rp>>)
0040 class owning_view : public view_interface<owning_view<_Rp>> {
0041   _Rp __r_ = _Rp();
0042
0043 public:
0044   _LIBCPP_HIDE_FROM_ABI owning_view()
0045     requires default_initializable<_Rp>
0046   = default;
0047   _LIBCPP_HIDE_FROM_ABI constexpr owning_view(_Rp&& __r) : __r_(std::move(__r)) {}
0048
0049   _LIBCPP_HIDE_FROM_ABI owning_view(owning_view&&)            = default;
0050   _LIBCPP_HIDE_FROM_ABI owning_view& operator=(owning_view&&) = default;
0051
0052   _LIBCPP_HIDE_FROM_ABI constexpr _Rp& base() & noexcept { return __r_; }
0053   _LIBCPP_HIDE_FROM_ABI constexpr const _Rp& base() const& noexcept { return __r_; }
0054   _LIBCPP_HIDE_FROM_ABI constexpr _Rp&& base() && noexcept { return std::move(__r_); }
0055   _LIBCPP_HIDE_FROM_ABI constexpr const _Rp&& base() const&& noexcept { return std::move(__r_); }
0056
0057   _LIBCPP_HIDE_FROM_ABI constexpr iterator_t<_Rp> begin() { return ranges::begin(__r_); }
0058   _LIBCPP_HIDE_FROM_ABI constexpr sentinel_t<_Rp> end() { return ranges::end(__r_); }
0059   _LIBCPP_HIDE_FROM_ABI constexpr auto begin() const
0060     requires range<const _Rp>
0061   {
0062     return ranges::begin(__r_);
0063   }
0064   _LIBCPP_HIDE_FROM_ABI constexpr auto end() const
0065     requires range<const _Rp>
0066   {
0067     return ranges::end(__r_);
0068   }
0069
0070   _LIBCPP_HIDE_FROM_ABI constexpr bool empty()
0071     requires requires { ranges::empty(__r_); }
0072   {
0073     return ranges::empty(__r_);
0074   }
0075   _LIBCPP_HIDE_FROM_ABI constexpr bool empty() const
0076     requires requires { ranges::empty(__r_); }
0077   {
0078     return ranges::empty(__r_);
0079   }
0080
0081   _LIBCPP_HIDE_FROM_ABI constexpr auto size()
0082     requires sized_range<_Rp>
0083   {
0084     return ranges::size(__r_);
0085   }
0086   _LIBCPP_HIDE_FROM_ABI constexpr auto size() const
0087     requires sized_range<const _Rp>
0088   {
0089     return ranges::size(__r_);
0090   }
0091
0092   _LIBCPP_HIDE_FROM_ABI constexpr auto data()
0093     requires contiguous_range<_Rp>
0094   {
0095     return ranges::data(__r_);
0096   }
0097   _LIBCPP_HIDE_FROM_ABI constexpr auto data() const
0098     requires contiguous_range<const _Rp>
0099   {
0100     return ranges::data(__r_);
0101   }
0102 };
0103 _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(owning_view);
0104
0105 template <class _Tp>
0106 inline constexpr bool enable_borrowed_range<owning_view<_Tp>> = enable_borrowed_range<_Tp>;
0107
0108 } // namespace ranges
0109
0110 #endif // _LIBCPP_STD_VER >= 20
0111
0112 _LIBCPP_END_NAMESPACE_STD
0113
0114 _LIBCPP_POP_MACROS
0115
0116 #endif // _LIBCPP___CXX03___RANGES_OWNING_VIEW_H