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___NUMERIC_INCLUSIVE_SCAN_H
11#define _LIBCPP___NUMERIC_INCLUSIVE_SCAN_H
12
13#include <__config>
14#include <__functional/operations.h>
15#include <__iterator/iterator_traits.h>
16#include <__utility/move.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
24#if _LIBCPP_STD_VER >= 17
25
26template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp>
27_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
28inclusive_scan(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryOp __b, _Tp __init) {
29  for (; __first != __last; ++__first, (void)++__result) {
30    __init    = __b(__init, *__first);
31    *__result = __init;
32  }
33  return __result;
34}
35
36template <class _InputIterator, class _OutputIterator, class _BinaryOp>
37_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
38inclusive_scan(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryOp __b) {
39  if (__first != __last) {
40    typename iterator_traits<_InputIterator>::value_type __init = *__first;
41    *__result++                                                 = __init;
42    if (++__first != __last)
43      return std::inclusive_scan(__first, __last, __result, __b, __init);
44  }
45
46  return __result;
47}
48
49template <class _InputIterator, class _OutputIterator>
50_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
51inclusive_scan(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
52  return std::inclusive_scan(__first, __last, __result, std::plus<>());
53}
54
55#endif // _LIBCPP_STD_VER >= 17
56
57_LIBCPP_END_NAMESPACE_STD
58
59#endif // _LIBCPP___NUMERIC_INCLUSIVE_SCAN_H
60