libcxx/include/__iterator/ranges_iterator_traits.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___ITERATOR_RANGES_ITERATOR_TRAITS_H
  11 #define _LIBCPP___ITERATOR_RANGES_ITERATOR_TRAITS_H
  12
  13 #include <__config>
  14 #include <__fwd/pair.h>
  15 #include <__ranges/concepts.h>
  16 #include <__type_traits/add_const.h>
  17 #include <__type_traits/remove_const.h>
  18
  19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  20 #  pragma GCC system_header
  21 #endif
  22
  23 _LIBCPP_BEGIN_NAMESPACE_STD
  24
  25 #if _LIBCPP_STD_VER >= 23
  26
  27 template <ranges::input_range _Range>
  28 using __range_key_type = __remove_const_t<typename ranges::range_value_t<_Range>::first_type>;
  29
  30 template <ranges::input_range _Range>
  31 using __range_mapped_type = typename ranges::range_value_t<_Range>::second_type;
  32
  33 template <ranges::input_range _Range>
  34 using __range_to_alloc_type =
  35     pair<add_const_t<typename ranges::range_value_t<_Range>::first_type>,
  36          typename ranges::range_value_t<_Range>::second_type>;
  37
  38 #endif
  39
  40 _LIBCPP_END_NAMESPACE_STD
  41
  42 #endif // _LIBCPP___ITERATOR_RANGES_ITERATOR_TRAITS_H