xref: /openbsd-src/gnu/llvm/libcxx/include/__numeric/adjacent_difference.h (revision 4bdff4bed0e3d54e55670334c7d0077db4170f86)
1*4bdff4beSrobert // -*- C++ -*-
2*4bdff4beSrobert //===----------------------------------------------------------------------===//
3*4bdff4beSrobert //
4*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information.
6*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7*4bdff4beSrobert //
8*4bdff4beSrobert //===----------------------------------------------------------------------===//
9*4bdff4beSrobert 
10*4bdff4beSrobert #ifndef _LIBCPP___NUMERIC_ADJACENT_DIFFERENCE_H
11*4bdff4beSrobert #define _LIBCPP___NUMERIC_ADJACENT_DIFFERENCE_H
12*4bdff4beSrobert 
13*4bdff4beSrobert #include <__config>
14*4bdff4beSrobert #include <__iterator/iterator_traits.h>
15*4bdff4beSrobert #include <__utility/move.h>
16*4bdff4beSrobert 
17*4bdff4beSrobert #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18*4bdff4beSrobert #  pragma GCC system_header
19*4bdff4beSrobert #endif
20*4bdff4beSrobert 
21*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD
22*4bdff4beSrobert 
23*4bdff4beSrobert template <class _InputIterator, class _OutputIterator>
24*4bdff4beSrobert _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
25*4bdff4beSrobert _OutputIterator
adjacent_difference(_InputIterator __first,_InputIterator __last,_OutputIterator __result)26*4bdff4beSrobert adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
27*4bdff4beSrobert {
28*4bdff4beSrobert     if (__first != __last)
29*4bdff4beSrobert     {
30*4bdff4beSrobert         typename iterator_traits<_InputIterator>::value_type __acc(*__first);
31*4bdff4beSrobert         *__result = __acc;
32*4bdff4beSrobert         for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
33*4bdff4beSrobert         {
34*4bdff4beSrobert             typename iterator_traits<_InputIterator>::value_type __val(*__first);
35*4bdff4beSrobert #if _LIBCPP_STD_VER > 17
36*4bdff4beSrobert             *__result = __val - _VSTD::move(__acc);
37*4bdff4beSrobert #else
38*4bdff4beSrobert             *__result = __val - __acc;
39*4bdff4beSrobert #endif
40*4bdff4beSrobert             __acc = _VSTD::move(__val);
41*4bdff4beSrobert         }
42*4bdff4beSrobert     }
43*4bdff4beSrobert     return __result;
44*4bdff4beSrobert }
45*4bdff4beSrobert 
46*4bdff4beSrobert template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
47*4bdff4beSrobert _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
48*4bdff4beSrobert _OutputIterator
adjacent_difference(_InputIterator __first,_InputIterator __last,_OutputIterator __result,_BinaryOperation __binary_op)49*4bdff4beSrobert adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
50*4bdff4beSrobert                       _BinaryOperation __binary_op)
51*4bdff4beSrobert {
52*4bdff4beSrobert     if (__first != __last)
53*4bdff4beSrobert     {
54*4bdff4beSrobert         typename iterator_traits<_InputIterator>::value_type __acc(*__first);
55*4bdff4beSrobert         *__result = __acc;
56*4bdff4beSrobert         for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
57*4bdff4beSrobert         {
58*4bdff4beSrobert             typename iterator_traits<_InputIterator>::value_type __val(*__first);
59*4bdff4beSrobert #if _LIBCPP_STD_VER > 17
60*4bdff4beSrobert             *__result = __binary_op(__val, _VSTD::move(__acc));
61*4bdff4beSrobert #else
62*4bdff4beSrobert             *__result = __binary_op(__val, __acc);
63*4bdff4beSrobert #endif
64*4bdff4beSrobert             __acc = _VSTD::move(__val);
65*4bdff4beSrobert         }
66*4bdff4beSrobert     }
67*4bdff4beSrobert     return __result;
68*4bdff4beSrobert }
69*4bdff4beSrobert 
70*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD
71*4bdff4beSrobert 
72*4bdff4beSrobert #endif // _LIBCPP___NUMERIC_ADJACENT_DIFFERENCE_H
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