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_PARTIAL_SUM_H
11#define _LIBCPP___NUMERIC_PARTIAL_SUM_H
12
13#include <__config>
14#include <__iterator/iterator_traits.h>
15#include <__utility/move.h>
16
17#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18#  pragma GCC system_header
19#endif
20
21_LIBCPP_BEGIN_NAMESPACE_STD
22
23template <class _InputIterator, class _OutputIterator>
24_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
25_OutputIterator
26partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
27{
28    if (__first != __last)
29    {
30        typename iterator_traits<_InputIterator>::value_type __t(*__first);
31        *__result = __t;
32        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
33        {
34#if _LIBCPP_STD_VER > 17
35            __t = _VSTD::move(__t) + *__first;
36#else
37            __t = __t + *__first;
38#endif
39            *__result = __t;
40        }
41    }
42    return __result;
43}
44
45template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
46_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
47_OutputIterator
48partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
49              _BinaryOperation __binary_op)
50{
51    if (__first != __last)
52    {
53        typename iterator_traits<_InputIterator>::value_type __t(*__first);
54        *__result = __t;
55        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
56        {
57#if _LIBCPP_STD_VER > 17
58            __t = __binary_op(_VSTD::move(__t), *__first);
59#else
60            __t = __binary_op(__t, *__first);
61#endif
62            *__result = __t;
63        }
64    }
65    return __result;
66}
67
68_LIBCPP_END_NAMESPACE_STD
69
70#endif // _LIBCPP___NUMERIC_PARTIAL_SUM_H
71