libcxx/include/__algorithm/copy_if.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___ALGORITHM_COPY_IF_H
  10 #define _LIBCPP___ALGORITHM_COPY_IF_H
  11
  12 #include <__config>
  13 #include <__functional/identity.h>
  14 #include <__type_traits/invoke.h>
  15 #include <__utility/move.h>
  16 #include <__utility/pair.h>
  17
  18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  19 #  pragma GCC system_header
  20 #endif
  21
  22 _LIBCPP_PUSH_MACROS
  23 #include <__undef_macros>
  24
  25 _LIBCPP_BEGIN_NAMESPACE_STD
  26
  27 template <class _InIter, class _Sent, class _OutIter, class _Proj, class _Pred>
  28 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
  29 __copy_if(_InIter __first, _Sent __last, _OutIter __result, _Pred& __pred, _Proj& __proj) {
  30   for (; __first != __last; ++__first) {
  31     if (std::__invoke(__pred, std::__invoke(__proj, *__first))) {
  32       *__result = *__first;
  33       ++__result;
  34     }
  35   }
  36   return std::make_pair(std::move(__first), std::move(__result));
  37 }
  38
  39 template <class _InputIterator, class _OutputIterator, class _Predicate>
  40 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
  41 copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred) {
  42   __identity __proj;
  43   return std::__copy_if(__first, __last, __result, __pred, __proj).second;
  44 }
  45
  46 _LIBCPP_END_NAMESPACE_STD
  47
  48 _LIBCPP_POP_MACROS
  49
  50 #endif // _LIBCPP___ALGORITHM_COPY_IF_H