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___ALGORITHM_MERGE_H
10#define _LIBCPP___ALGORITHM_MERGE_H
11
12#include <__algorithm/comp.h>
13#include <__algorithm/comp_ref_type.h>
14#include <__algorithm/copy.h>
15#include <__config>
16#include <__iterator/iterator_traits.h>
17
18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19# pragma GCC system_header
20#endif
21
22_LIBCPP_BEGIN_NAMESPACE_STD
23
24template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
25_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator __merge(
26 _InputIterator1 __first1,
27 _InputIterator1 __last1,
28 _InputIterator2 __first2,
29 _InputIterator2 __last2,
30 _OutputIterator __result,
31 _Compare __comp) {
32 for (; __first1 != __last1; ++__result) {
33 if (__first2 == __last2)
34 return std::copy(__first1, __last1, __result);
35 if (__comp(*__first2, *__first1)) {
36 *__result = *__first2;
37 ++__first2;
38 } else {
39 *__result = *__first1;
40 ++__first1;
41 }
42 }
43 return std::copy(__first2, __last2, __result);
44}
45
46template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
47inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
48merge(_InputIterator1 __first1,
49 _InputIterator1 __last1,
50 _InputIterator2 __first2,
51 _InputIterator2 __last2,
52 _OutputIterator __result,
53 _Compare __comp) {
54 return std::__merge<__comp_ref_type<_Compare> >(__first1, __last1, __first2, __last2, __result, __comp);
55}
56
57template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
58inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
59merge(_InputIterator1 __first1,
60 _InputIterator1 __last1,
61 _InputIterator2 __first2,
62 _InputIterator2 __last2,
63 _OutputIterator __result) {
64 return std::merge(__first1, __last1, __first2, __last2, __result, __less<>());
65}
66
67_LIBCPP_END_NAMESPACE_STD
68
69#endif // _LIBCPP___ALGORITHM_MERGE_H
70