将一个复杂对象的构建与它的表示分离，使得同样的构建过程可以创建不同的表示。
以建造小人为例子，一共需建造6个部分，头部、身体、左右手、左右脚。与工厂模式不同，建造者模式是在导向者的控制下一步一步构造产品的。建造小人就是在控制下一步步构造出来的。创建者模式可以能更精细的控制构建过程，从而能更精细的控制所得产品的内部结构。
#include <iostream>
class IBuilder
{
public:
IBuilder() {}
virtual ~IBuilder() {}
virtual void buildHead() = 0;
virtual void buildBody() = 0;
virtual void buildLeftArm() = 0;
virtual void buildRightArm() = 0;
virtual void buildLeftLeg() = 0;
virtual void buildRightLeg() = 0;
};
class CThinBuilder : public IBuilder
{
public:
CThinBuilder() {}
~CThinBuilder() {}
void buildHead() { std::cout << "build thin head" << ‘\n‘; }
void buildBody() { std::cout << "build thin body" << ‘\n‘; }
void buildLeftArm() { std::cout << "build thin left arm" << ‘\n‘; }
void buildRightArm() { std::cout << "build thin right arm" << ‘\n‘; }
void buildLeftLeg() { std::cout << "build thin left leg" << ‘\n‘; }
void buildRightLeg() { std::cout << "build thin right leg" << ‘\n‘; }
};
class CFatBuilder : public IBuilder
{
public:
CFatBuilder() {}
~CFatBuilder() {}
void buildHead() { std::cout << "build fat head" << ‘\n‘; }
void buildBody() { std::cout << "build fat body" << ‘\n‘; }
void buildLeftArm() { std::cout << "build fat left arm" << ‘\n‘; }
void buildRightArm() { std::cout << "build fat right arm" << ‘\n‘; }
void buildLeftLeg() { std::cout << "build fat left leg" << ‘\n‘; }
void buildRightLeg() { std::cout << "build fat right leg" << ‘\n‘; }
};
class CDirector
{
public:
CDirector(IBuilder* pBuilder) : m_pBuilder(pBuilder) {}
~CDirector() {}
void create()
{
m_pBuilder->buildHead();
m_pBuilder->buildBody();
m_pBuilder->buildLeftArm();
m_pBuilder->buildRightArm();
m_pBuilder->buildLeftLeg();
m_pBuilder->buildRightLeg();
}
private:
IBuilder* m_pBuilder;
};
int main()
{
IBuilder* builder = new CFatBuilder();
CDirector director(builder);
director.create();
delete builder;
return 0;
}
原文：https://www.cnblogs.com/zuofaqi/p/10475596.html