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_N_H
11 #define _LIBCPP___ALGORITHM_FOR_EACH_N_H
12 
13 #include <__config>
14 #include <__utility/convert_to_integral.h>
15 
16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17 #  pragma GCC system_header
18 #endif
19 
20 _LIBCPP_BEGIN_NAMESPACE_STD
21 
22 #if _LIBCPP_STD_VER >= 17
23 
24 template <class _InputIterator, class _Size, class _Function>
25 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _InputIterator
for_each_n(_InputIterator __first,_Size __orig_n,_Function __f)26 for_each_n(_InputIterator __first, _Size __orig_n, _Function __f) {
27   typedef decltype(std::__convert_to_integral(__orig_n)) _IntegralSize;
28   _IntegralSize __n = __orig_n;
29   while (__n > 0) {
30     __f(*__first);
31     ++__first;
32     --__n;
33   }
34   return __first;
35 }
36 
37 #endif
38 
39 _LIBCPP_END_NAMESPACE_STD
40 
41 #endif // _LIBCPP___ALGORITHM_FOR_EACH_N_H
42