mapnik/include/ptr.hpp
2005-06-14 15:06:59 +00:00

107 lines
2.5 KiB
C++

/* This file is part of Mapnik (c++ mapping toolkit)
* Copyright (C) 2005 Artem Pavlenko
*
* Mapnik 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.
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
//$Id: ptr.hpp 39 2005-04-10 20:39:53Z pavlenko $
#ifndef PTR_HPP
#define PTR_HPP
namespace mapnik
{
template <typename T> struct DefaultDeletePolicy
{
static void destroy(T* p)
{
delete p;
}
};
template <typename T,
template <typename T> class DeallocPolicy=DefaultDeletePolicy>
class ref_ptr
{
private:
T* ptr_;
int* pCount_;
public:
T* operator->() {return ptr_;}
const T* operator->() const {return ptr_;}
T* get() {return ptr_;}
const T* get() const {return ptr_;}
const T& operator *() const {return *ptr_;}
T& operator *() {return *ptr_;}
explicit ref_ptr(T* ptr=0)
:ptr_(ptr),pCount_(new int(1)) {}
ref_ptr(const ref_ptr& rhs)
:ptr_(rhs.ptr_),pCount_(rhs.pCount_)
{
(*pCount_)++;
}
ref_ptr& operator=(const ref_ptr& rhs)
{
if (ptr_==rhs.ptr_) return *this;
if (--(*pCount_)==0)
{
DeallocPolicy<T>::destroy(ptr_);
delete pCount_;
}
ptr_=rhs.ptr_;
pCount_=rhs.pCount_;
(*pCount_)++;
return *this;
}
bool operator !() const
{
return ptr_==0;
}
operator bool () const
{
return ptr_!=0;
}
inline friend bool operator==(const ref_ptr& lhs,
const T* rhs)
{
return lhs.ptr_==rhs;
}
inline friend bool operator==(const T* lhs,
const ref_ptr& rhs)
{
return lhs==rhs.ptr_;
}
inline friend bool operator!=(const ref_ptr& lhs,
const T* rhs)
{
return lhs.ptr_!=rhs;
}
inline friend bool operator!=(const T* lhs,
const ref_ptr& rhs)
{
return lhs!=rhs.ptr_;
}
~ref_ptr()
{
if (--(*pCount_)==0)
{
DeallocPolicy<T>::destroy(ptr_);
delete pCount_;
}
}
};
}
#endif //PTR_HPP