libcxx/include/__ranges/all.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_ALL_H
  11 #define _LIBCPP___RANGES_ALL_H
  12
  13 #include <__config>
  14 #include <__functional/compose.h>         // TODO(modules): Those should not be required
  15 #include <__functional/perfect_forward.h> //
  16 #include <__iterator/concepts.h>
  17 #include <__iterator/iterator_traits.h>
  18 #include <__ranges/access.h>
  19 #include <__ranges/concepts.h>
  20 #include <__ranges/owning_view.h>
  21 #include <__ranges/range_adaptor.h>
  22 #include <__ranges/ref_view.h>
  23 #include <__type_traits/decay.h>
  24 #include <__utility/auto_cast.h>
  25 #include <__utility/declval.h>
  26 #include <__utility/forward.h>
  27
  28 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  29 #  pragma GCC system_header
  30 #endif
  31
  32 _LIBCPP_BEGIN_NAMESPACE_STD
  33
  34 #if _LIBCPP_STD_VER >= 20
  35
  36 namespace ranges::views {
  37
  38 namespace __all {
  39   struct __fn : __range_adaptor_closure<__fn> {
  40     template<class _Tp>
  41       requires ranges::view<decay_t<_Tp>>
  42     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
  43     constexpr auto operator()(_Tp&& __t) const
  44       noexcept(noexcept(_LIBCPP_AUTO_CAST(std::forward<_Tp>(__t))))
  45       -> decltype(_LIBCPP_AUTO_CAST(std::forward<_Tp>(__t)))
  46     {
  47       return _LIBCPP_AUTO_CAST(std::forward<_Tp>(__t));
  48     }
  49
  50     template<class _Tp>
  51       requires (!ranges::view<decay_t<_Tp>>) &&
  52                requires (_Tp&& __t) { ranges::ref_view{std::forward<_Tp>(__t)}; }
  53     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
  54     constexpr auto operator()(_Tp&& __t) const
  55       noexcept(noexcept(ranges::ref_view{std::forward<_Tp>(__t)}))
  56     {
  57       return ranges::ref_view{std::forward<_Tp>(__t)};
  58     }
  59
  60     template<class _Tp>
  61       requires (!ranges::view<decay_t<_Tp>> &&
  62                 !requires (_Tp&& __t) { ranges::ref_view{std::forward<_Tp>(__t)}; } &&
  63                  requires (_Tp&& __t) { ranges::owning_view{std::forward<_Tp>(__t)}; })
  64     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
  65     constexpr auto operator()(_Tp&& __t) const
  66       noexcept(noexcept(ranges::owning_view{std::forward<_Tp>(__t)}))
  67     {
  68       return ranges::owning_view{std::forward<_Tp>(__t)};
  69     }
  70   };
  71 } // namespace __all
  72
  73 inline namespace __cpo {
  74   inline constexpr auto all = __all::__fn{};
  75 } // namespace __cpo
  76
  77 template<ranges::viewable_range _Range>
  78 using all_t = decltype(views::all(std::declval<_Range>()));
  79
  80 } // namespace ranges::views
  81
  82 #endif // _LIBCPP_STD_VER >= 20
  83
  84 _LIBCPP_END_NAMESPACE_STD
  85
  86 #endif // _LIBCPP___RANGES_ALL_H