__cxx03/__iterator/mergeable.h

0001 // -*- C++ -*-
0002 //===----------------------------------------------------------------------===//
0003 //
0004 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0005 // See https://llvm.org/LICENSE.txt for license information.
0006 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0007 //
0008 //===----------------------------------------------------------------------===//
0009
0010 #ifndef _LIBCPP___CXX03___ITERATOR_MERGEABLE_H
0011 #define _LIBCPP___CXX03___ITERATOR_MERGEABLE_H
0012
0013 #include <__cxx03/__config>
0014 #include <__cxx03/__functional/identity.h>
0015 #include <__cxx03/__functional/ranges_operations.h>
0016 #include <__cxx03/__iterator/concepts.h>
0017 #include <__cxx03/__iterator/projected.h>
0018
0019 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0020 #  pragma GCC system_header
0021 #endif
0022
0023 _LIBCPP_BEGIN_NAMESPACE_STD
0024
0025 #if _LIBCPP_STD_VER >= 20
0026
0027 template <class _Input1,
0028           class _Input2,
0029           class _Output,
0030           class _Comp  = ranges::less,
0031           class _Proj1 = identity,
0032           class _Proj2 = identity>
0033 concept mergeable =
0034     input_iterator<_Input1> && input_iterator<_Input2> && weakly_incrementable<_Output> &&
0035     indirectly_copyable<_Input1, _Output> && indirectly_copyable<_Input2, _Output> &&
0036     indirect_strict_weak_order<_Comp, projected<_Input1, _Proj1>, projected<_Input2, _Proj2>>;
0037
0038 #endif // _LIBCPP_STD_VER >= 20
0039
0040 _LIBCPP_END_NAMESPACE_STD
0041
0042 #endif // _LIBCPP___CXX03___ITERATOR_MERGEABLE_H