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_AFTER_CXX17 25 _OutputIterator 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_AFTER_CXX17 48 _OutputIterator 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