71 lines
1.9 KiB
C++
71 lines
1.9 KiB
C++
#ifndef _REFCNTR_H_
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#define _REFCNTR_H_
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/* Copyright (C) 2014 J.F.Dockes
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the
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* Free Software Foundation, Inc.,
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* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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// See Stroustrup C++ 3rd ed, p. 783
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// This is only used if std::shared_ptr is not available
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template <class X> class RefCntr {
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X *rep;
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int *pcount;
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public:
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RefCntr()
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: rep(0), pcount(0)
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{}
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explicit RefCntr(X *pp)
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: rep(pp), pcount(new int(1))
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{}
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RefCntr(const RefCntr &r)
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: rep(r.rep), pcount(r.pcount)
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{
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if (pcount)
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(*pcount)++;
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}
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RefCntr& operator=(const RefCntr& r)
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{
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if (rep == r.rep)
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return *this;
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if (pcount && --(*pcount) == 0) {
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delete rep;
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delete pcount;
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}
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rep = r.rep;
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pcount = r.pcount;
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if (pcount)
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(*pcount)++;
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return *this;
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}
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void reset() {
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if (pcount && --(*pcount) == 0) {
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delete rep;
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delete pcount;
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}
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rep = 0;
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pcount = 0;
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}
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~RefCntr()
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{
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reset();
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}
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X *operator->() {return rep;}
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X *get() const {return rep;}
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int use_count() const {return pcount ? *pcount : 0;}
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operator bool() const {return rep != 0;}
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};
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#endif /*_REFCNTR_H_ */
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