#ifndef _REFCNTR_H_
#define _REFCNTR_H_
/* Copyright (C) 2014 J.F.Dockes
* 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.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
// See Stroustrup C++ 3rd ed, p. 783
// This is only used if std::shared_ptr is not available
template <class X> class RefCntr {
X *rep;
int *pcount;
public:
RefCntr()
: rep(0), pcount(0)
{}
explicit RefCntr(X *pp)
: rep(pp), pcount(new int(1))
{}
RefCntr(const RefCntr &r)
: rep(r.rep), pcount(r.pcount)
{
if (pcount)
(*pcount)++;
}
RefCntr& operator=(const RefCntr& r)
{
if (rep == r.rep)
return *this;
if (pcount && --(*pcount) == 0) {
delete rep;
delete pcount;
}
rep = r.rep;
pcount = r.pcount;
if (pcount)
(*pcount)++;
return *this;
}
void reset() {
if (pcount && --(*pcount) == 0) {
delete rep;
delete pcount;
}
rep = 0;
pcount = 0;
}
~RefCntr()
{
reset();
}
X *operator->() {return rep;}
X *get() const {return rep;}
int use_count() const {return pcount ? *pcount : 0;}
operator bool() const {return rep != 0;}
};
#endif /*_REFCNTR_H_ */