libcxx/include/__cxx03/__fwd/subrange.h

   1 //===---------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===---------------------------------------------------------------------===//
   8
   9 #ifndef _LIBCPP___FWD_SUBRANGE_H
  10 #define _LIBCPP___FWD_SUBRANGE_H
  11
  12 #include <__cxx03/__concepts/copyable.h>
  13 #include <__cxx03/__config>
  14 #include <__cxx03/__iterator/concepts.h>
  15 #include <__cxx03/cstddef>
  16
  17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  18 #  pragma GCC system_header
  19 #endif
  20
  21 #if _LIBCPP_STD_VER >= 20
  22
  23 _LIBCPP_BEGIN_NAMESPACE_STD
  24
  25 namespace ranges {
  26
  27 enum class subrange_kind : bool { unsized, sized };
  28
  29 template <input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent, subrange_kind _Kind>
  30   requires(_Kind == subrange_kind::sized || !sized_sentinel_for<_Sent, _Iter>)
  31 class _LIBCPP_TEMPLATE_VIS subrange;
  32
  33 template <size_t _Index, class _Iter, class _Sent, subrange_kind _Kind>
  34   requires((_Index == 0 && copyable<_Iter>) || _Index == 1)
  35 _LIBCPP_HIDE_FROM_ABI constexpr auto get(const subrange<_Iter, _Sent, _Kind>&);
  36
  37 template <size_t _Index, class _Iter, class _Sent, subrange_kind _Kind>
  38   requires(_Index < 2)
  39 _LIBCPP_HIDE_FROM_ABI constexpr auto get(subrange<_Iter, _Sent, _Kind>&&);
  40
  41 } // namespace ranges
  42
  43 using ranges::get;
  44
  45 _LIBCPP_END_NAMESPACE_STD
  46
  47 #endif // _LIBCPP_STD_VER >= 20
  48
  49 #endif // _LIBCPP___FWD_SUBRANGE_H