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_ADJACENT_DIFFERENCE_H
11 #define _LIBCPP___NUMERIC_ADJACENT_DIFFERENCE_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
23 template <class _InputIterator, class _OutputIterator>
24 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
25 _OutputIterator
adjacent_difference(_InputIterator __first,_InputIterator __last,_OutputIterator __result)26 adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
27 {
28 if (__first != __last)
29 {
30 typename iterator_traits<_InputIterator>::value_type __acc(*__first);
31 *__result = __acc;
32 for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
33 {
34 typename iterator_traits<_InputIterator>::value_type __val(*__first);
35 #if _LIBCPP_STD_VER > 17
36 *__result = __val - _VSTD::move(__acc);
37 #else
38 *__result = __val - __acc;
39 #endif
40 __acc = _VSTD::move(__val);
41 }
42 }
43 return __result;
44 }
45
46 template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
47 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
48 _OutputIterator
adjacent_difference(_InputIterator __first,_InputIterator __last,_OutputIterator __result,_BinaryOperation __binary_op)49 adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
50 _BinaryOperation __binary_op)
51 {
52 if (__first != __last)
53 {
54 typename iterator_traits<_InputIterator>::value_type __acc(*__first);
55 *__result = __acc;
56 for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
57 {
58 typename iterator_traits<_InputIterator>::value_type __val(*__first);
59 #if _LIBCPP_STD_VER > 17
60 *__result = __binary_op(__val, _VSTD::move(__acc));
61 #else
62 *__result = __binary_op(__val, __acc);
63 #endif
64 __acc = _VSTD::move(__val);
65 }
66 }
67 return __result;
68 }
69
70 _LIBCPP_END_NAMESPACE_STD
71
72 #endif // _LIBCPP___NUMERIC_ADJACENT_DIFFERENCE_H
73