stl_numeric.h
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// Numeric functions implementation -*- C++ -*-
// Copyright (C) 2001-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file bits/stl_numeric.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{numeric}
*/
#ifndef _STL_NUMERIC_H
#define _STL_NUMERIC_H 1
#include <bits/concept_check.h>
#include <debug/debug.h>
#include <bits/move.h> // For _GLIBCXX_MOVE
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/** @defgroup numeric_ops Generalized Numeric operations
* @ingroup algorithms
*/
#if __cplusplus >= 201103L
/**
* @brief Create a range of sequentially increasing values.
*
* For each element in the range @p [first,last) assigns @p value and
* increments @p value as if by @p ++value.
*
* @param __first Start of range.
* @param __last End of range.
* @param __value Starting value.
* @return Nothing.
* @ingroup numeric_ops
*/
template<typename _ForwardIterator, typename _Tp>
_GLIBCXX20_CONSTEXPR
void
iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value)
{
// concept requirements
__glibcxx_function_requires(_Mutable_ForwardIteratorConcept<
_ForwardIterator>)
__glibcxx_function_requires(_ConvertibleConcept<_Tp,
typename iterator_traits<_ForwardIterator>::value_type>)
__glibcxx_requires_valid_range(__first, __last);
for (; __first != __last; ++__first)
{
*__first = __value;
++__value;
}
}
#endif
_GLIBCXX_END_NAMESPACE_VERSION
_GLIBCXX_BEGIN_NAMESPACE_ALGO
#if __cplusplus > 201703L
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 2055. std::move in std::accumulate and other algorithms
# define _GLIBCXX_MOVE_IF_20(_E) std::move(_E)
#else
# define _GLIBCXX_MOVE_IF_20(_E) _E
#endif
/// @addtogroup numeric_ops
/// @{
/**
* @brief Accumulate values in a range.
*
* Accumulates the values in the range [first,last) using operator+(). The
* initial value is @a init. The values are processed in order.
*
* @param __first Start of range.
* @param __last End of range.
* @param __init Starting value to add other values to.
* @return The final sum.
*/
template<typename _InputIterator, typename _Tp>
_GLIBCXX20_CONSTEXPR
inline _Tp
accumulate(_InputIterator __first, _InputIterator __last, _Tp __init)
{
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
__glibcxx_requires_valid_range(__first, __last);
for (; __first != __last; ++__first)
__init = _GLIBCXX_MOVE_IF_20(__init) + *__first;
return __init;
}
/**
* @brief Accumulate values in a range with operation.
*
* Accumulates the values in the range `[first,last)` using the function
* object `__binary_op`. The initial value is `__init`. The values are
* processed in order.
*
* @param __first Start of range.
* @param __last End of range.
* @param __init Starting value to add other values to.
* @param __binary_op Function object to accumulate with.
* @return The final sum.
*/
template<typename _InputIterator, typename _Tp, typename _BinaryOperation>
_GLIBCXX20_CONSTEXPR
inline _Tp
accumulate(_InputIterator __first, _InputIterator __last, _Tp __init,
_BinaryOperation __binary_op)
{
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
__glibcxx_requires_valid_range(__first, __last);
for (; __first != __last; ++__first)
__init = __binary_op(_GLIBCXX_MOVE_IF_20(__init), *__first);
return __init;
}
/**
* @brief Compute inner product of two ranges.
*
* Starting with an initial value of @p __init, multiplies successive
* elements from the two ranges and adds each product into the accumulated
* value using operator+(). The values in the ranges are processed in
* order.
*
* @param __first1 Start of range 1.
* @param __last1 End of range 1.
* @param __first2 Start of range 2.
* @param __init Starting value to add other values to.
* @return The final inner product.
*/
template<typename _InputIterator1, typename _InputIterator2, typename _Tp>
_GLIBCXX20_CONSTEXPR
inline _Tp
inner_product(_InputIterator1 __first1, _InputIterator1 __last1,
_InputIterator2 __first2, _Tp __init)
{
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
__glibcxx_requires_valid_range(__first1, __last1);
for (; __first1 != __last1; ++__first1, (void)++__first2)
__init = _GLIBCXX_MOVE_IF_20(__init) + (*__first1 * *__first2);
return __init;
}
/**
* @brief Compute inner product of two ranges.
*
* Starting with an initial value of @p __init, applies @p __binary_op2 to
* successive elements from the two ranges and accumulates each result into
* the accumulated value using @p __binary_op1. The values in the ranges are
* processed in order.
*
* @param __first1 Start of range 1.
* @param __last1 End of range 1.
* @param __first2 Start of range 2.
* @param __init Starting value to add other values to.
* @param __binary_op1 Function object to accumulate with.
* @param __binary_op2 Function object to apply to pairs of input values.
* @return The final inner product.
*/
template<typename _InputIterator1, typename _InputIterator2, typename _Tp,
typename _BinaryOperation1, typename _BinaryOperation2>
_GLIBCXX20_CONSTEXPR
inline _Tp
inner_product(_InputIterator1 __first1, _InputIterator1 __last1,
_InputIterator2 __first2, _Tp __init,
_BinaryOperation1 __binary_op1,
_BinaryOperation2 __binary_op2)
{
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator1>)
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator2>)
__glibcxx_requires_valid_range(__first1, __last1);
for (; __first1 != __last1; ++__first1, (void)++__first2)
__init = __binary_op1(_GLIBCXX_MOVE_IF_20(__init),
__binary_op2(*__first1, *__first2));
return __init;
}
/**
* @brief Return list of partial sums
*
* Accumulates the values in the range [first,last) using the @c + operator.
* As each successive input value is added into the total, that partial sum
* is written to @p __result. Therefore, the first value in @p __result is
* the first value of the input, the second value in @p __result is the sum
* of the first and second input values, and so on.
*
* @param __first Start of input range.
* @param __last End of input range.
* @param __result Output sum.
* @return Iterator pointing just beyond the values written to __result.
*/
template<typename _InputIterator, typename _OutputIterator>
_GLIBCXX20_CONSTEXPR
_OutputIterator
partial_sum(_InputIterator __first, _InputIterator __last,
_OutputIterator __result)
{
typedef typename iterator_traits<_InputIterator>::value_type _ValueType;
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
__glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
_ValueType>)
__glibcxx_requires_valid_range(__first, __last);
if (__first == __last)
return __result;
_ValueType __value = *__first;
*__result = __value;
while (++__first != __last)
{
__value = _GLIBCXX_MOVE_IF_20(__value) + *__first;
*++__result = __value;
}
return ++__result;
}
/**
* @brief Return list of partial sums
*
* Accumulates the values in the range [first,last) using @p __binary_op.
* As each successive input value is added into the total, that partial sum
* is written to @p __result. Therefore, the first value in @p __result is
* the first value of the input, the second value in @p __result is the sum
* of the first and second input values, and so on.
*
* @param __first Start of input range.
* @param __last End of input range.
* @param __result Output sum.
* @param __binary_op Function object.
* @return Iterator pointing just beyond the values written to __result.
*/
template<typename _InputIterator, typename _OutputIterator,
typename _BinaryOperation>
_GLIBCXX20_CONSTEXPR
_OutputIterator
partial_sum(_InputIterator __first, _InputIterator __last,
_OutputIterator __result, _BinaryOperation __binary_op)
{
typedef typename iterator_traits<_InputIterator>::value_type _ValueType;
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
__glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
_ValueType>)
__glibcxx_requires_valid_range(__first, __last);
if (__first == __last)
return __result;
_ValueType __value = *__first;
*__result = __value;
while (++__first != __last)
{
__value = __binary_op(_GLIBCXX_MOVE_IF_20(__value), *__first);
*++__result = __value;
}
return ++__result;
}
/**
* @brief Return differences between adjacent values.
*
* Computes the difference between adjacent values in the range
* [first,last) using operator-() and writes the result to @p __result.
*
* @param __first Start of input range.
* @param __last End of input range.
* @param __result Output sums.
* @return Iterator pointing just beyond the values written to result.
*
* _GLIBCXX_RESOLVE_LIB_DEFECTS
* DR 539. partial_sum and adjacent_difference should mention requirements
*/
template<typename _InputIterator, typename _OutputIterator>
_GLIBCXX20_CONSTEXPR
_OutputIterator
adjacent_difference(_InputIterator __first,
_InputIterator __last, _OutputIterator __result)
{
typedef typename iterator_traits<_InputIterator>::value_type _ValueType;
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
__glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
_ValueType>)
__glibcxx_requires_valid_range(__first, __last);
if (__first == __last)
return __result;
_ValueType __value = *__first;
*__result = __value;
while (++__first != __last)
{
_ValueType __tmp = *__first;
*++__result = __tmp - _GLIBCXX_MOVE_IF_20(__value);
__value = _GLIBCXX_MOVE(__tmp);
}
return ++__result;
}
/**
* @brief Return differences between adjacent values.
*
* Computes the difference between adjacent values in the range
* [__first,__last) using the function object @p __binary_op and writes the
* result to @p __result.
*
* @param __first Start of input range.
* @param __last End of input range.
* @param __result Output sum.
* @param __binary_op Function object.
* @return Iterator pointing just beyond the values written to result.
*
* _GLIBCXX_RESOLVE_LIB_DEFECTS
* DR 539. partial_sum and adjacent_difference should mention requirements
*/
template<typename _InputIterator, typename _OutputIterator,
typename _BinaryOperation>
_GLIBCXX20_CONSTEXPR
_OutputIterator
adjacent_difference(_InputIterator __first, _InputIterator __last,
_OutputIterator __result, _BinaryOperation __binary_op)
{
typedef typename iterator_traits<_InputIterator>::value_type _ValueType;
// concept requirements
__glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
__glibcxx_function_requires(_OutputIteratorConcept<_OutputIterator,
_ValueType>)
__glibcxx_requires_valid_range(__first, __last);
if (__first == __last)
return __result;
_ValueType __value = *__first;
*__result = __value;
while (++__first != __last)
{
_ValueType __tmp = *__first;
*++__result = __binary_op(__tmp, _GLIBCXX_MOVE_IF_20(__value));
__value = _GLIBCXX_MOVE(__tmp);
}
return ++__result;
}
/// @} group numeric_ops
#undef _GLIBCXX_MOVE_IF_20
_GLIBCXX_END_NAMESPACE_ALGO
} // namespace std
#endif /* _STL_NUMERIC_H */
concept_check.h
move.h
debug.h
std::accumulate
constexpr _Tp accumulate(_InputIterator __first, _InputIterator __last, _Tp __init)
Accumulate values in a range.
Definition: stl_numeric.h:134
std::adjacent_difference
constexpr _OutputIterator adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
Return differences between adjacent values.
Definition: stl_numeric.h:338
std::iota
constexpr void iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value)
Create a range of sequentially increasing values.
Definition: stl_numeric.h:88
std::partial_sum
constexpr _OutputIterator partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
Return list of partial sums.
Definition: stl_numeric.h:256
std::inner_product
constexpr _Tp inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _Tp __init)
Compute inner product of two ranges.
Definition: stl_numeric.h:190
std
ISO C++ entities toplevel namespace is std.
std::iterator_traits
Traits class for iterators.
Definition: stl_iterator_base_types.h:178