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/*
* The Mana World Server
* Copyright 2004 The Mana World Development Team
*
* This file is part of The Mana World.
*
* The Mana World 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 any later version.
*
* The Mana World 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 The Mana World; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id$
*/
#ifndef _TMWSERV_COUNTED_PTR_H_
#define _TMWSERV_COUNTED_PTR_H_
namespace tmwserv
{
namespace utils
{
/**
* Class for counted reference semantics. It deletes the object to which it
* refers when the last CountedPtr that refers to it is destroyed.
*
* @copyright Nicolai M. Josuttis
* (The C++ standard library: a tutorial and reference).
*
* Notes from kindjal:
* - should we use the Boost's shared_ptr instead?
* - reference-counted smart pointers are very useful if we want automatic
* memory management with STL containers (e.g. vector of pointers).
*/
template <typename T>
class CountedPtr
{
public:
/**
* Constructor.
* Initialize pointer with existing pointer.
*
* It is required that the pointer p is a return value of new.
*/
explicit
CountedPtr(T* p = 0)
: ptr(p),
count(new long(1))
{
// NOOP
}
/**
* Destructor.
* Delete value if this was the last owner.
*/
~CountedPtr(void)
throw()
{
dispose();
}
/**
* Copy pointer (one more owner).
*/
CountedPtr(const CountedPtr<T>& p)
throw()
: ptr(p.ptr),
count(p.count)
{
++*count;
}
/**
* Assignment (unshare old and share new value).
*/
CountedPtr<T>&
operator=(const CountedPtr<T>& p)
throw()
{
if (this != &p) {
dispose();
ptr = p.ptr;
count = p.count;
++*count;
}
return *this;
}
/**
* Access the value to which the pointer refers.
*/
T&
operator*(void) const
throw()
{
return *ptr;
}
/**
* Access the pointer.
*/
T*
operator->(void) const
throw()
{
return ptr;
}
/**
* Get the pointer (mimic std::auto_ptr::get()).
*/
T*
get(void) const
throw()
{
return ptr;
}
private:
/**
* Manage the counter and free memory.
*/
void
dispose(void)
{
if (--*count == 0) {
delete count;
delete ptr;
}
}
private:
T* ptr; /**< pointer to the value */
long* count; /**< shared number of owners */
};
} // namespace utils
} // namespace tmwserv
#endif // _TMWSERV_COUNTED_PTR_H_
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