桥模式

和装饰器模式类似，不同点在于装饰器模式是用于追加功能的，桥模式是从现有的库中调用方法，库是独立于实现化角色的，因此后者不用继承自前者。核心还是传递指针，然后调用方法。

比如从几个不同平台的库中任意调用及组合方法，参考下例

class Implement 
{
public:
    virtual void func_1() = 0;
    virtual void func_2() = 0;
    ~Implement(){}
};
class Implement_1 :public Implement
{
public:
    void func_1() {
        cout << "Implement_1::func1" << endl;
    }
    void func_2() {
        cout << "Implement_1::func_2" << endl;
    }
};
class Implement_2 :public Implement
{
public:
    void func_1() {
        cout << "Implement_2::func1" << endl;
    }
    void func_2() {
        cout << "Implement_2::func_2" << endl;
    }
};
class composition
{
protected:
    Implement* _Implement;
public:
    composition(Implement* Implement):_Implement(Implement){}
    virtual ~composition(){}
    virtual void operation() = 0;
};
class composition_1:public composition
{
public:
    composition_1(Implement* Implement) :composition(Implement) {}
    virtual void operation() {
        composition::_Implement->func_1();
        composition::_Implement->func_2();
    }
};
class composition_2 :public composition
{
public:
    composition_2(Implement* Implement) :composition(Implement) {}
    virtual void operation() {
        composition::_Implement->func_2();
        composition::_Implement->func_1();
    }
};



void test03() {

    Implement* imp1 = new Implement_1;
    Implement* imp2 = new Implement_2;

    composition* com1 = new composition_1(imp1);
    composition* com2 = new composition_2(imp1);
    com1->operation();
    com2->operation();

    composition* com3 = new composition_1(imp2);
    composition* com4 = new composition_2(imp2);
    com3->operation();
    com4->operation();



    delete imp1;
    delete imp2;
    delete com1;
    delete com2;
    delete com3;
    delete com4;

}