libcxx/include/__algorithm/for_each.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___ALGORITHM_FOR_EACH_H
  11 #define _LIBCPP___ALGORITHM_FOR_EACH_H
  12
  13 #include <__algorithm/for_each_segment.h>
  14 #include <__config>
  15 #include <__iterator/segmented_iterator.h>
  16 #include <__ranges/movable_box.h>
  17 #include <__type_traits/enable_if.h>
  18 #include <__utility/in_place.h>
  19 #include <__utility/move.h>
  20
  21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  22 #  pragma GCC system_header
  23 #endif
  24
  25 _LIBCPP_PUSH_MACROS
  26 #include <__undef_macros>
  27
  28 _LIBCPP_BEGIN_NAMESPACE_STD
  29
  30 template <class _InputIterator, class _Function>
  31 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Function
  32 for_each(_InputIterator __first, _InputIterator __last, _Function __f) {
  33   for (; __first != __last; ++__first)
  34     __f(*__first);
  35   return __f;
  36 }
  37
  38 // __movable_box is available in C++20, but is actually a copyable-box, so optimization is only correct in C++23
  39 #if _LIBCPP_STD_VER >= 23
  40 template <class _SegmentedIterator, class _Function>
  41   requires __is_segmented_iterator<_SegmentedIterator>::value
  42 _LIBCPP_HIDE_FROM_ABI constexpr _Function
  43 for_each(_SegmentedIterator __first, _SegmentedIterator __last, _Function __func) {
  44   ranges::__movable_box<_Function> __wrapped_func(in_place, std::move(__func));
  45   std::__for_each_segment(__first, __last, [&](auto __lfirst, auto __llast) {
  46     __wrapped_func =
  47         ranges::__movable_box<_Function>(in_place, std::for_each(__lfirst, __llast, std::move(*__wrapped_func)));
  48   });
  49   return std::move(*__wrapped_func);
  50 }
  51 #endif // _LIBCPP_STD_VER >= 23
  52
  53 _LIBCPP_END_NAMESPACE_STD
  54
  55 _LIBCPP_POP_MACROS
  56
  57 #endif // _LIBCPP___ALGORITHM_FOR_EACH_H