libcxx/include/__memory/concepts.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___MEMORY_CONCEPTS_H
  11 #define _LIBCPP___MEMORY_CONCEPTS_H
  12
  13 #include <__concepts/same_as.h>
  14 #include <__config>
  15 #include <__iterator/concepts.h>
  16 #include <__iterator/iterator_traits.h>
  17 #include <__iterator/readable_traits.h>
  18 #include <__ranges/access.h>
  19 #include <__ranges/concepts.h>
  20 #include <__type_traits/is_reference.h>
  21 #include <__type_traits/remove_cvref.h>
  22 #include <__type_traits/remove_reference.h> // TODO(modules): This should not be required
  23
  24 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  25 #  pragma GCC system_header
  26 #endif
  27
  28 _LIBCPP_BEGIN_NAMESPACE_STD
  29
  30 #if _LIBCPP_STD_VER >= 20
  31
  32 namespace ranges {
  33
  34 // [special.mem.concepts]
  35
  36 // This concept ensures that uninitialized algorithms can construct an object
  37 // at the address pointed-to by the iterator, which requires an lvalue.
  38 template <class _Ip>
  39 concept __nothrow_input_iterator =
  40     input_iterator<_Ip> &&
  41     is_lvalue_reference_v<iter_reference_t<_Ip>> &&
  42     same_as<remove_cvref_t<iter_reference_t<_Ip>>, iter_value_t<_Ip>>;
  43
  44 template <class _Sp, class _Ip>
  45 concept __nothrow_sentinel_for = sentinel_for<_Sp, _Ip>;
  46
  47 template <class _Rp>
  48 concept __nothrow_input_range =
  49     range<_Rp> &&
  50     __nothrow_input_iterator<iterator_t<_Rp>> &&
  51     __nothrow_sentinel_for<sentinel_t<_Rp>, iterator_t<_Rp>>;
  52
  53 template <class _Ip>
  54 concept __nothrow_forward_iterator =
  55     __nothrow_input_iterator<_Ip> &&
  56     forward_iterator<_Ip> &&
  57     __nothrow_sentinel_for<_Ip, _Ip>;
  58
  59 template <class _Rp>
  60 concept __nothrow_forward_range =
  61     __nothrow_input_range<_Rp> &&
  62     __nothrow_forward_iterator<iterator_t<_Rp>>;
  63
  64 } // namespace ranges
  65
  66 #endif // _LIBCPP_STD_VER >= 20
  67
  68 _LIBCPP_END_NAMESPACE_STD
  69
  70 #endif // _LIBCPP___MEMORY_CONCEPTS_H