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 
26 template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp>
27 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
28 inclusive_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 
36 template <class _InputIterator, class _OutputIterator, class _BinaryOp>
37 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
38 inclusive_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 _VSTD::inclusive_scan(__first, __last, __result, __b, __init);
44   }
45 
46   return __result;
47 }
48 
49 template <class _InputIterator, class _OutputIterator>
50 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator inclusive_scan(_InputIterator __first,
51                                                                                        _InputIterator __last,
52                                                                                        _OutputIterator __result) {
53   return _VSTD::inclusive_scan(__first, __last, __result, _VSTD::plus<>());
54 }
55 
56 #endif // _LIBCPP_STD_VER >= 17
57 
58 _LIBCPP_END_NAMESPACE_STD
59 
60 #endif // _LIBCPP___NUMERIC_INCLUSIVE_SCAN_H
61