C++桥接模式（Bridge）

UML类图（仅供参考）如下：

桥接模式解决的问题：

抽象类之间为聚合关系，将抽象部分与实现部分分离，使它们都可以独立的变化，这样他们的子类就可以任意聚合在一起

源码

#include <iostream>

// 抽象类,桥的一部分
class CAbstractionImplement
{
public:
	virtual ~CAbstractionImplement() {}

	// 定义接口,表示该类所支持的操作
	virtual void Operation() = 0;

protected:
	CAbstractionImplement() {}
};

// 具体实现A
class CConcreteAbstractionImplementA :public CAbstractionImplement
{
public:
	virtual void Operation()
	{
		std::cout << "CConcreteAbstractionImplementA::Operation" << std::endl;
	}
};

// 具体实现B
class CConcreteAbstractionImplementB :public CAbstractionImplement
{
public:
	virtual void Operation()
	{
		std::cout << "CConcreteAbstractionImplementB::Operation" << std::endl;
	}
};

// 抽象类,桥的另一部分
class CAbstraction
{
public:
	virtual ~CAbstraction() {}

	// 定义接口,表示该类所支持的操作
	virtual void Operation() = 0;

protected:

	CAbstraction(CAbstractionImplement* imp) :_imp(imp) {}

	// CAbstraction与CAbstractionImplement为聚合
	// 这样他们的子类可以以任何方式组合，从而实现桥接模式
	CAbstractionImplement *_imp;
};

// 具体实现A
class CRefinedAbstractionA :public CAbstraction
{
public:
	CRefinedAbstractionA(CAbstractionImplement* imp) :CAbstraction(imp) {}

	virtual void Operation()
	{
		std::cout << "CRefinedAbstractionA::Operation" << std::endl;
		this->_imp->Operation();
	}
};

// 具体实现A
class CRefinedAbstractionB :public CAbstraction
{
public:
	CRefinedAbstractionB(CAbstractionImplement* imp) :CAbstraction(imp) {}

	virtual void Operation()
	{
		std::cout << "CRefinedAbstractionB::Operation" << std::endl;
		this->_imp->Operation();
	}
};

// 测试
int main()
{
	CAbstractionImplement* imp = new CConcreteAbstractionImplementA();
	CAbstraction* abs = new CRefinedAbstractionA(imp);
	abs->Operation();

	std::cout << "-----------------------------------------" << std::endl;

	CAbstractionImplement* imp1 = new CConcreteAbstractionImplementB();
	CAbstraction* abs1 = new CRefinedAbstractionA(imp1);
	abs1->Operation();

	std::cout << "-----------------------------------------" << std::endl;

	CAbstractionImplement* imp2 = new CConcreteAbstractionImplementA();
	CAbstraction* abs2 = new CRefinedAbstractionB(imp2);		
	abs2->Operation();

	std::cout << "-----------------------------------------" << std::endl;

	CAbstractionImplement* imp3 = new CConcreteAbstractionImplementB();
	CAbstraction* abs3 = new CRefinedAbstractionB(imp3);
	abs3->Operation();
}

好处

1、抽象和实现的分离。

2、优秀的扩展能力。

3、实现细节对客户透明