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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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
* of the License, or (at your option) any later version.
*
* This program 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 program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*/
#ifndef COMMON_ALGORITHM_H
#define COMMON_ALGORITHM_H
#include "common/scummsys.h"
#include "common/func.h"
namespace Common {
/**
* Copies data from the range [first, last) to [dst, dst + (last - first)).
* It requires the range [dst, dst + (last - first)) to be valid.
* It also requires dst not to be in the range [first, last).
*/
template<class In, class Out>
Out copy(In first, In last, Out dst) {
while (first != last)
*dst++ = *first++;
return dst;
}
/**
* Copies data from the range [first, last) to [dst - (last - first), dst).
* It requires the range [dst - (last - first), dst) to be valid.
* It also requires dst not to be in the range [first, last).
*
* Unlike copy copy_backward copies the data from the end to the beginning.
*/
template<class In, class Out>
Out copy_backward(In first, In last, Out dst) {
while (first != last)
*--dst = *--last;
return dst;
}
/**
* Copies data from the range [first, last) to [dst, dst + (last - first)).
* It requires the range [dst, dst + (last - first)) to be valid.
* It also requires dst not to be in the range [first, last).
*
* Unlike copy or copy_backward it does not copy all data. It only copies
* a data element when operator() of the op parameter returns true for the
* passed data element.
*/
template<class In, class Out, class Op>
Out copy_if(In first, In last, Out dst, Op op) {
while (first != last) {
if (op(*first))
*dst++ = *first;
++first;
}
return dst;
}
// Our 'specialized' 'set_to' template for char, signed char and unsigned char arrays.
// Since C++ doesn't support partial specialized template functions (currently) we
// are going this way...
// With this we assure the usage of memset for those, which should be
// faster than a simple loop like for the generic 'set_to'.
template<class Value>
signed char *set_to(signed char *first, signed char *last, Value val) {
memset(first, (val & 0xFF), last - first);
return last;
}
template<class Value>
unsigned char *set_to(unsigned char *first, unsigned char *last, Value val) {
memset(first, (val & 0xFF), last - first);
return last;
}
template<class Value>
char *set_to(char *first, char *last, Value val) {
memset(first, (val & 0xFF), last - first);
return last;
}
/**
* Sets all elements in the range [first, last) to val.
*/
template<class In, class Value>
In set_to(In first, In last, Value val) {
while (first != last)
*first++ = val;
return first;
}
/**
* Finds the first data value in the range [first, last) matching v.
* For data comperance it uses operator == of the data elements.
*/
template<class In, class T>
In find(In first, In last, const T &v) {
while (first != last) {
if (*first == v)
return first;
++first;
}
return last;
}
/**
* Finds the first data value in the range [first, last) for which
* the specified predicate p returns true.
*/
template<class In, class Pred>
In find_if(In first, In last, Pred p) {
while (first != last) {
if (p(*first))
return first;
++first;
}
return last;
}
/**
* Applies the function f on all elements of the range [first, last).
* The processing order is from beginning to end.
*/
template<class In, class Op>
Op for_each(In first, In last, Op f) {
while (first != last) f(*first++);
return f;
}
template<typename T>
unsigned distance(T * first, T * last) {
return last - first;
}
template<typename T>
unsigned distance(T first, T last) {
unsigned n = 0;
while (first != last) {
++n;
++first;
}
return n;
}
template<typename T>
T * _sort_choose_pivot(T * first, T * last) {
return first + distance(first, last) / 2;
}
template<typename T>
T _sort_choose_pivot(T first, T last) {
unsigned n = distance(first, last);
n /= 2;
while (n--)
++first;
return first;
}
template<typename T, class StrictWeakOrdering>
T _sort_partition(T first, T last, T pivot, StrictWeakOrdering &comp) {
--last;
SWAP(*pivot, *last);
T sorted;
for (sorted = first; first != last; ++first) {
if (!comp(*last, *first)) {
if (first != sorted)
SWAP(*first, *sorted);
++sorted;
}
}
SWAP(*last, *sorted);
return sorted;
}
/**
* Simple sort function, modeled after std::sort.
* It compares data with the given comparator object comp.
*/
template<typename T, class StrictWeakOrdering>
void sort(T first, T last, StrictWeakOrdering comp) {
if (first == last)
return;
T pivot = _sort_choose_pivot(first, last);
pivot = _sort_partition(first, last, pivot, comp);
sort<T, StrictWeakOrdering>(first, pivot, comp);
sort<T, StrictWeakOrdering>(++pivot, last, comp);
}
/**
* Simple sort function, modeled after std::sort.
* Use it like this: sort(container.begin(), container.end()).
*/
template<typename T>
void sort(T * first, T * last) {
sort(first, last, Common::Less<T>());
}
///\todo add value_type to all iterators and add default sort variant with Common::Less<T::value_type>()
} // End of namespace Common
#endif
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