libcxx/include/__ranges/data.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_DATA_H
  11 #define _LIBCPP___RANGES_DATA_H
  12
  13 #include <__concepts/class_or_enum.h>
  14 #include <__config>
  15 #include <__iterator/concepts.h>
  16 #include <__iterator/iterator_traits.h>
  17 #include <__memory/pointer_traits.h>
  18 #include <__ranges/access.h>
  19 #include <__type_traits/decay.h>
  20 #include <__type_traits/is_object.h>
  21 #include <__type_traits/is_pointer.h>
  22 #include <__type_traits/is_reference.h>
  23 #include <__type_traits/remove_pointer.h>
  24 #include <__type_traits/remove_reference.h>
  25 #include <__utility/auto_cast.h>
  26
  27 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  28 #  pragma GCC system_header
  29 #endif
  30
  31 _LIBCPP_BEGIN_NAMESPACE_STD
  32
  33 #if _LIBCPP_STD_VER >= 20
  34
  35 // [range.prim.data]
  36
  37 namespace ranges {
  38 namespace __data {
  39   template <class _Tp>
  40   concept __ptr_to_object = is_pointer_v<_Tp> && is_object_v<remove_pointer_t<_Tp>>;
  41
  42   template <class _Tp>
  43   concept __member_data =
  44     __can_borrow<_Tp> &&
  45     __workaround_52970<_Tp> &&
  46     requires(_Tp&& __t) {
  47       { _LIBCPP_AUTO_CAST(__t.data()) } -> __ptr_to_object;
  48     };
  49
  50   template <class _Tp>
  51   concept __ranges_begin_invocable =
  52     !__member_data<_Tp> &&
  53     __can_borrow<_Tp> &&
  54     requires(_Tp&& __t) {
  55       { ranges::begin(__t) } -> contiguous_iterator;
  56     };
  57
  58   struct __fn {
  59     template <__member_data _Tp>
  60     _LIBCPP_HIDE_FROM_ABI
  61     constexpr auto operator()(_Tp&& __t) const
  62         noexcept(noexcept(__t.data())) {
  63       return __t.data();
  64     }
  65
  66     template<__ranges_begin_invocable _Tp>
  67     _LIBCPP_HIDE_FROM_ABI
  68     constexpr auto operator()(_Tp&& __t) const
  69         noexcept(noexcept(std::to_address(ranges::begin(__t)))) {
  70       return std::to_address(ranges::begin(__t));
  71     }
  72   };
  73 } // namespace __data
  74
  75 inline namespace __cpo {
  76   inline constexpr auto data = __data::__fn{};
  77 } // namespace __cpo
  78 } // namespace ranges
  79
  80 // [range.prim.cdata]
  81
  82 namespace ranges {
  83 namespace __cdata {
  84   struct __fn {
  85     template <class _Tp>
  86       requires is_lvalue_reference_v<_Tp&&>
  87     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
  88     constexpr auto operator()(_Tp&& __t) const
  89       noexcept(noexcept(ranges::data(static_cast<const remove_reference_t<_Tp>&>(__t))))
  90       -> decltype(      ranges::data(static_cast<const remove_reference_t<_Tp>&>(__t)))
  91       { return          ranges::data(static_cast<const remove_reference_t<_Tp>&>(__t)); }
  92
  93     template <class _Tp>
  94       requires is_rvalue_reference_v<_Tp&&>
  95     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI
  96     constexpr auto operator()(_Tp&& __t) const
  97       noexcept(noexcept(ranges::data(static_cast<const _Tp&&>(__t))))
  98       -> decltype(      ranges::data(static_cast<const _Tp&&>(__t)))
  99       { return          ranges::data(static_cast<const _Tp&&>(__t)); }
 100   };
 101 } // namespace __cdata
 102
 103 inline namespace __cpo {
 104   inline constexpr auto cdata = __cdata::__fn{};
 105 } // namespace __cpo
 106 } // namespace ranges
 107
 108 #endif // _LIBCPP_STD_VER >= 20
 109
 110 _LIBCPP_END_NAMESPACE_STD
 111
 112 #endif // _LIBCPP___RANGES_DATA_H