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_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
adjacent_difference(_InputIterator __first,_InputIterator __last,_OutputIterator __result)28 adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
29 if (__first != __last) {
30 typename iterator_traits<_InputIterator>::value_type __acc(*__first);
31 *__result = __acc;
32 for (++__first, (void)++__result; __first != __last; ++__first, (void)++__result) {
33 typename iterator_traits<_InputIterator>::value_type __val(*__first);
34 #if _LIBCPP_STD_VER >= 20
35 *__result = __val - std::move(__acc);
36 #else
37 *__result = __val - __acc;
38 #endif
39 __acc = std::move(__val);
40 }
41 }
42 return __result;
43 }
44
45 template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
adjacent_difference(_InputIterator __first,_InputIterator __last,_OutputIterator __result,_BinaryOperation __binary_op)46 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator adjacent_difference(
47 _InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryOperation __binary_op) {
48 if (__first != __last) {
49 typename iterator_traits<_InputIterator>::value_type __acc(*__first);
50 *__result = __acc;
51 for (++__first, (void)++__result; __first != __last; ++__first, (void)++__result) {
52 typename iterator_traits<_InputIterator>::value_type __val(*__first);
53 #if _LIBCPP_STD_VER >= 20
54 *__result = __binary_op(__val, std::move(__acc));
55 #else
56 *__result = __binary_op(__val, __acc);
57 #endif
58 __acc = std::move(__val);
59 }
60 }
61 return __result;
62 }
63
64 _LIBCPP_END_NAMESPACE_STD
65
66 _LIBCPP_POP_MACROS
67
68 #endif // _LIBCPP___NUMERIC_ADJACENT_DIFFERENCE_H
69