freebsd-dev/contrib/libstdc++/include/bits/stl_numeric.h
2004-07-28 03:12:05 +00:00

327 lines
12 KiB
C++

// Numeric functions implementation -*- C++ -*-
// Copyright (C) 2001, 2004 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 2, 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.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
/*
*
* 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 stl_numeric.h
* This is an internal header file, included by other library headers.
* You should not attempt to use it directly.
*/
#ifndef _STL_NUMERIC_H
#define _STL_NUMERIC_H 1
#include <debug/debug.h>
namespace std
{
/**
* @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>
_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 = __init + *__first;
return __init;
}
/**
* @brief Accumulate values in a range with operation.
*
* Accumulates the values in the range [first,last) using the function
* object @a binary_op. 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.
* @param binary_op Function object to accumulate with.
* @return The final sum.
*/
template<typename _InputIterator, typename _Tp, typename _BinaryOperation>
_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(__init, *__first);
return __init;
}
/**
* @brief Compute inner product of two ranges.
*
* Starting with an initial value of @a 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>
_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, ++__first2)
__init = __init + (*__first1 * *__first2);
return __init;
}
/**
* @brief Compute inner product of two ranges.
*
* Starting with an initial value of @a init, applies @a binary_op2 to
* successive elements from the two ranges and accumulates each result into
* the accumulated value using @a 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>
_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, ++__first2)
__init = __binary_op1(__init, __binary_op2(*__first1, *__first2));
return __init;
}
/**
* @brief Return list of partial sums
*
* Accumulates the values in the range [first,last) using operator+().
* As each successive input value is added into the total, that partial sum
* is written to @a result. Therefore, the first value in result is the
* first value of the input, the second value in 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 to write sums to.
* @return Iterator pointing just beyond the values written to result.
*/
template<typename _InputIterator, typename _OutputIterator>
_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;
*__result = *__first;
_ValueType __value = *__first;
while (++__first != __last) {
__value = __value + *__first;
*++__result = __value;
}
return ++__result;
}
/**
* @brief Return list of partial sums
*
* Accumulates the values in the range [first,last) using operator+().
* As each successive input value is added into the total, that partial sum
* is written to @a result. Therefore, the first value in result is the
* first value of the input, the second value in 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 to write sums to.
* @return Iterator pointing just beyond the values written to result.
*/
template<typename _InputIterator, typename _OutputIterator, typename _BinaryOperation>
_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;
*__result = *__first;
_ValueType __value = *__first;
while (++__first != __last) {
__value = __binary_op(__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 @a result.
*
* @param first Start of input range.
* @param last End of input range.
* @param result Output to write sums to.
* @return Iterator pointing just beyond the values written to result.
*/
template<typename _InputIterator, typename _OutputIterator>
_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;
*__result = *__first;
_ValueType __value = *__first;
while (++__first != __last) {
_ValueType __tmp = *__first;
*++__result = __tmp - __value;
__value = __tmp;
}
return ++__result;
}
/**
* @brief Return differences between adjacent values.
*
* Computes the difference between adjacent values in the range
* [first,last) using the function object @a binary_op and writes the
* result to @a result.
*
* @param first Start of input range.
* @param last End of input range.
* @param result Output to write sums to.
* @return Iterator pointing just beyond the values written to result.
*/
template<typename _InputIterator, typename _OutputIterator, typename _BinaryOperation>
_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;
*__result = *__first;
_ValueType __value = *__first;
while (++__first != __last) {
_ValueType __tmp = *__first;
*++__result = __binary_op(__tmp, __value);
__value = __tmp;
}
return ++__result;
}
} // namespace std
#endif /* _STL_NUMERIC_H */