www.pudn.com > DCPlusPlus-src.zip > Pointer.h

/*  
 * Copyright (C) 2001-2004 Jacek Sieka, j_s at telia com 
 * 
 * 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. 
 */ 
 
#if !defined(AFX_POINTER_H__FCC38D23_858F_43AC_BF23_73FD708FDC82__INCLUDED_) 
#define AFX_POINTER_H__FCC38D23_858F_43AC_BF23_73FD708FDC82__INCLUDED_ 
 
#if _MSC_VER > 1000 
#pragma once 
#endif // _MSC_VER > 1000 
 
#include "Thread.h" 
 
class PointerBase 
{ 
public: 
	void inc() throw() { 
		dcassert(ref>=0); 
		Thread::safeInc(&ref); 
	} 
 
	void dec() throw() { 
		dcassert(ref>0); 
		 
		if ( (Thread::safeDec(&ref)) == 0 ) { 
			//dcdebug("Smart Object at 0x%08x deleted\n", this); 
			delete this; 
		} 
	} 
	bool unique() throw() { 
		return (ref == 1); 
	} 
	 
protected: 
	PointerBase() throw() : ref(0) { }; 
	 
	virtual ~PointerBase() throw() { 
		dcassert(!ref); 
	} 
 
private: 
	long ref; 
}; 
 
/** 
 * Note; don't forget to make the destructor virtual if deriving from this class 
 */ 
template  
class Pointer 
{ 
public: 
	Pointer ( PointerBase *aBase = 0) throw() : base(aBase) {	 
		if ( base ) { 
			base->inc(); 
		} 
	} 
	 
	Pointer( const Pointer &rhs ) throw() : base(rhs.base) {	    
		if ( base ) { 
			base->inc(); 
		} 
	} 
	 
	Pointer &operator =( const Pointer &rhs ) throw() { 
		if ( rhs.base ) { 
			rhs.base->inc(); 
		} 
		 
		if ( base ) { 
			base->dec(); 
		} 
		 
		base = rhs.base; 
		return *this; 
	} 
 
	Pointer &operator =( T* rhs ) throw() { 
		if (rhs) { 
			rhs->inc(); 
			if ( base ) { 
				base->dec(); 
			} 
			base = rhs; 
		} 
		 
		 
		return *this; 
	} 
	 
	~Pointer() throw() {  
		if ( base ) { 
			base->dec(); 
		} 
	} 
	 
	T*			operator->()		  { return		asT();	} 
	T&			operator* ()		  { return	   *asT();	} 
	const T*	operator->()  const   { return		asT();	} 
	const T&	operator* ()  const   { return	   *asT();	} 
	 
	operator		  bool()  const   { return base != NULL; } 
	 
	bool operator==(T* rhs) const { return (T*)base == rhs; }; 
	bool operator==(const Pointer& rhs) const { return base == rhs.base; }; 
	bool operator!=(T* rhs) const { return (T*)base != rhs; }; 
	bool operator!=(const Pointer& rhs) const { return base != rhs.base; }; 
	bool operator<(T* rhs) const { return (T*)base < rhs; }; 
	bool operator<(const Pointer& rhs) const { return base < rhs.base; }; 
	bool operator>(T* rhs) const { return (T*)base > rhs; }; 
	bool operator>(const Pointer& rhs) const { return base > rhs.base; }; 
	 
 
	static void swap ( Pointer &lhs, Pointer &rhs ) { 
		PointerBase *temp = lhs.base; 
		lhs.base = rhs.base; 
		rhs.base = temp; 
	} 
	 
	void release() { 
		if ( base ) { 
			base->dec(); 
			base = 0; 
		} 
	} 
private: 
	PointerBase* base; 
	 
	T* asT () {	 
		dcassert(base); 
		return (T*)base;	 
	} 
 
	const T* asT()	const {	 
		dcassert(base); 
		return (T*)base;	 
	} 
}; 
 
template  
bool operator==(T* lhs, const Pointer& rhs) { return rhs == lhs; }; 
template  
bool operator<(T* lhs, const Pointer& rhs) { return rhs > lhs; }; 
template  
bool operator>(T* lhs, const Pointer& rhs) { return rhs < lhs; }; 
 
template  
struct DeleteFunction { 
	void operator()(const T& p) const { delete p; }; 
}; 
 
#endif // !defined(AFX_POINTER_H__FCC38D23_858F_43AC_BF23_73FD708FDC82__INCLUDED_) 
 
/** 
 * @file 
 * $Id: Pointer.h,v 1.15 2004/09/06 12:32:42 arnetheduck Exp $ 
 */