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
26template <class _InputIterator, class _OutputIterator>
27_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
28adjacent_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
45template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
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