xref: /freebsd/contrib/llvm-project/libcxx/include/__numeric/partial_sum.h (revision cb14a3fe5122c879eae1fb480ed7ce82a699ddb6)
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_PUSH_MACROS
22 #include <__undef_macros>
23 
24 _LIBCPP_BEGIN_NAMESPACE_STD
25 
26 template <class _InputIterator, class _OutputIterator>
27 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
28 partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
29   if (__first != __last) {
30     typename iterator_traits<_InputIterator>::value_type __t(*__first);
31     *__result = __t;
32     for (++__first, (void)++__result; __first != __last; ++__first, (void)++__result) {
33 #if _LIBCPP_STD_VER >= 20
34       __t = std::move(__t) + *__first;
35 #else
36       __t = __t + *__first;
37 #endif
38       *__result = __t;
39     }
40   }
41   return __result;
42 }
43 
44 template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
45 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
46 partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryOperation __binary_op) {
47   if (__first != __last) {
48     typename iterator_traits<_InputIterator>::value_type __t(*__first);
49     *__result = __t;
50     for (++__first, (void)++__result; __first != __last; ++__first, (void)++__result) {
51 #if _LIBCPP_STD_VER >= 20
52       __t = __binary_op(std::move(__t), *__first);
53 #else
54       __t = __binary_op(__t, *__first);
55 #endif
56       *__result = __t;
57     }
58   }
59   return __result;
60 }
61 
62 _LIBCPP_END_NAMESPACE_STD
63 
64 _LIBCPP_POP_MACROS
65 
66 #endif // _LIBCPP___NUMERIC_PARTIAL_SUM_H
67