v1/__algorithm/merge.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___ALGORITHM_MERGE_H
0010 #define _LIBCPP___ALGORITHM_MERGE_H
0011
0012 #include <__algorithm/comp.h>
0013 #include <__algorithm/comp_ref_type.h>
0014 #include <__algorithm/copy.h>
0015 #include <__config>
0016
0017 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0018 #  pragma GCC system_header
0019 #endif
0020
0021 _LIBCPP_BEGIN_NAMESPACE_STD
0022
0023 template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
0024 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator __merge(
0025     _InputIterator1 __first1,
0026     _InputIterator1 __last1,
0027     _InputIterator2 __first2,
0028     _InputIterator2 __last2,
0029     _OutputIterator __result,
0030     _Compare __comp) {
0031   for (; __first1 != __last1; ++__result) {
0032     if (__first2 == __last2)
0033       return std::copy(__first1, __last1, __result);
0034     if (__comp(*__first2, *__first1)) {
0035       *__result = *__first2;
0036       ++__first2;
0037     } else {
0038       *__result = *__first1;
0039       ++__first1;
0040     }
0041   }
0042   return std::copy(__first2, __last2, __result);
0043 }
0044
0045 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
0046 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
0047 merge(_InputIterator1 __first1,
0048       _InputIterator1 __last1,
0049       _InputIterator2 __first2,
0050       _InputIterator2 __last2,
0051       _OutputIterator __result,
0052       _Compare __comp) {
0053   return std::__merge<__comp_ref_type<_Compare> >(__first1, __last1, __first2, __last2, __result, __comp);
0054 }
0055
0056 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
0057 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
0058 merge(_InputIterator1 __first1,
0059       _InputIterator1 __last1,
0060       _InputIterator2 __first2,
0061       _InputIterator2 __last2,
0062       _OutputIterator __result) {
0063   return std::merge(__first1, __last1, __first2, __last2, __result, __less<>());
0064 }
0065
0066 _LIBCPP_END_NAMESPACE_STD
0067
0068 #endif // _LIBCPP___ALGORITHM_MERGE_H