建造者模式 Builder Mode

创建者模式是创建型模式中最负责的一个设计模式了，创建者负责构建一个对象的各个部分，并且完成组装的过程，我们可以这么理解创建

者模式，创建者模式类似与一个步骤基本固定，但是每个步骤中的具体形式却又可以变化的这类对象的创建。

#include<iostream>
using namespace std;

class Builder{
public:
    virtual void buildHead() = 0;
    virtual void buildHand() = 0;
    virtual void buildLeg() = 0;
    virtual void show() = 0;
};

class ThinPerson:public Builder{
public:
    void buildHead(){
        cout<<"build ThinPerson head"<<endl;
    }
    void buildHand(){
        cout<<"build ThinPerson hand"<<endl;
    }
    void buildLeg(){
        cout<<"build ThinPerson leg"<<endl;
    }

    void show(){
        cout<<"thinperson"<<endl;
    }
};

class FatPerson:public Builder{
public:
    void buildHead(){
        cout<<"build FatPerson head"<<endl;
    }
    void buildHand(){
        cout<<"build FatPerson hand"<<endl;
    }
    void buildLeg(){
        cout<<"build FatPerson leg"<<endl;
    }

    void show(){
        cout<<"fatperson"<<endl;
    }
};

class Director{
public:
    Director(Builder * builder){
        m_builder = builder;
    }
    void construct(){
        m_builder->buildHead();
        m_builder->buildHand();
        m_builder->buildLeg();
    }
    Builder * getProduct(){
        return m_builder;
    }
private:
    Builder * m_builder;
};
int main(int argc, char* argv[])
{
    Builder * pbuilder = new FatPerson();
    Director * pdirector = new Director(pbuilder);
    pdirector->construct();     //之前在new FatPerson中new了，在这会进行具体构造
    
    pdirector->getProduct()->show();  //这是和pbuilder一样的，指向同一对象
    delete pbuilder;
    delete pdirector;
    return 0;
}