factory.h

设计模式模板源码

/////////////////////////////////////////////////////////////////////////////
// Factory.h : Object factory design pattern
//
#ifndef _XP_OBJECTFACTORY_H__
#define _XP_OBJECTFACTORY_H__

#include "..\GuidCast.h"


template <typename _Base>
class CObjectFactoryBase
{
public:
    virtual _Base* CreateObject() const = 0;
	virtual void DestroyObject(_Base* pObject) const = 0;
};


template <typename _Base, typename _Derived, typename _A = std::allocator<_Derived> >
class CObjectFactory: 
	public CObjectFactoryBase<_Base>
{
public:
    virtual _Base* CreateObject() const 
	{ 
		_A a; 
		_Derived* p = a.allocate(1, NULL); 
		a.construct(p, _Derived()); 
		return p;
	}

	virtual void DestroyObject(_Base* pObject) const
	{ 
		_A a; 
		_Derived* pD = guid_cast<_Derived*>(pObject);
		if (pD) {
			a.destroy(pD);
			a.deallocate(pD, 1);
		}
	}
};

#endif  // #ifndef _XP_OBJECTFACTORY_H__