libcxx/include/__cxx03/__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___CXX03___RANGES_ALL_H
  11 #define _LIBCPP___CXX03___RANGES_ALL_H
  12
  13 #include <__cxx03/__config>
  14 #include <__cxx03/__functional/compose.h>         // TODO(modules): Those should not be required
  15 #include <__cxx03/__functional/perfect_forward.h> //
  16 #include <__cxx03/__iterator/concepts.h>
  17 #include <__cxx03/__iterator/iterator_traits.h>
  18 #include <__cxx03/__ranges/access.h>
  19 #include <__cxx03/__ranges/concepts.h>
  20 #include <__cxx03/__ranges/owning_view.h>
  21 #include <__cxx03/__ranges/range_adaptor.h>
  22 #include <__cxx03/__ranges/ref_view.h>
  23 #include <__cxx03/__type_traits/decay.h>
  24 #include <__cxx03/__utility/auto_cast.h>
  25 #include <__cxx03/__utility/declval.h>
  26 #include <__cxx03/__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 constexpr auto operator()(_Tp&& __t) const noexcept(
  43       noexcept(_LIBCPP_AUTO_CAST(std::forward<_Tp>(__t)))) -> decltype(_LIBCPP_AUTO_CAST(std::forward<_Tp>(__t))) {
  44     return _LIBCPP_AUTO_CAST(std::forward<_Tp>(__t));
  45   }
  46
  47   template <class _Tp>
  48     requires(!ranges::view<decay_t<_Tp>>) && requires(_Tp&& __t) { ranges::ref_view{std::forward<_Tp>(__t)}; }
  49   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t) const
  50       noexcept(noexcept(ranges::ref_view{std::forward<_Tp>(__t)})) {
  51     return ranges::ref_view{std::forward<_Tp>(__t)};
  52   }
  53
  54   template <class _Tp>
  55     requires(
  56         !ranges::view<decay_t<_Tp>> && !requires(_Tp&& __t) { ranges::ref_view{std::forward<_Tp>(__t)}; } &&
  57         requires(_Tp&& __t) { ranges::owning_view{std::forward<_Tp>(__t)}; })
  58   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t) const
  59       noexcept(noexcept(ranges::owning_view{std::forward<_Tp>(__t)})) {
  60     return ranges::owning_view{std::forward<_Tp>(__t)};
  61   }
  62 };
  63 } // namespace __all
  64
  65 inline namespace __cpo {
  66 inline constexpr auto all = __all::__fn{};
  67 } // namespace __cpo
  68
  69 template <ranges::viewable_range _Range>
  70 using all_t = decltype(views::all(std::declval<_Range>()));
  71
  72 } // namespace ranges::views
  73
  74 #endif // _LIBCPP_STD_VER >= 20
  75
  76 _LIBCPP_END_NAMESPACE_STD
  77
  78 #endif // _LIBCPP___CXX03___RANGES_ALL_H