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工厂方法创建的对象应该从何处删除?

factory-pattern factory design-patterns c++

1

Aquarius_Girl · 技术社区 · 8 年前

创建对象的方式和位置 returnShapeType 是否删除?
这是一个工厂方法演示程序。

请出示密码。

class Shape
{
public:
    Shape() {}
    virtual void print() {std::cout << "\nFrom shape print";}
};

class Triangle: public Shape
{
public:
    Triangle(){}
    virtual void print() {std::cout << "\nFrom triangle print";}
};

class Rectangle: public Shape
{
public:
    Rectangle(){}
    virtual void print() {std::cout << "\nFrom rect print";}
};

class CreateShapeObject
{
public:
    CreateShapeObject() {}

    Shape *returnShapeType( std::string arg )
    {
        if (arg == "Triangle")
            return new Triangle;
        else if (arg == "Rectangle")
            return new Rectangle;
    }
};

////////////

class EndDeveloper
{
public:
    CreateShapeObject obj;

    EndDeveloper()
    {
        Shape *p = obj.returnShapeType("Triangle");
        p->print();

        Shape *q = obj.returnShapeType("Rectangle");
        q->print();


    }
};

3 回复 | 直到 8 年前

1

2

R Sahu 8 年前

CreateShapeObject

创建形状对象 ShapeObjectManager

2

6

krisz 8 年前

unique_ptr

std::unique_ptr<Shape> returnShapeType(const std::string& arg)
{
    if (arg == "Triangle")
        return std::make_unique<Triangle>();
    else if (arg == "Rectangle")
        return std::make_unique<Rectangle>();
    throw std::invalid_argument("Invalid shape");
}

auto

auto shape = obj.returnShapeType("Triangle");

shared_ptr 以下内容:

std::shared_ptr<Shape> shape = obj.returnShapeType("Triangle");

3

2

Yunnosch 8 年前

new
(是否通过工厂)负责 delete 也一样。