C++原型模式实现对象快速克隆方法

Cloneable

Prototype

clone()

clone()

clone()

#include <iostream>
#include <string>
#include <vector>
#include <memory> // 使用智能指针管理内存更安全

// 抽象原型基类
class Shape {
public:
    virtual ~Shape() = default;
    virtual std::unique_ptr<Shape> clone() const = 0; // 返回智能指针
    virtual void draw() const = 0;
};

// 具体原型类：圆形
class Circle : public Shape {
private:
    int radius;
    std::string color;

public:
    Circle(int r, const std::string& c) : radius(r), color(c) {}

    // 拷贝构造函数：用于深拷贝
    Circle(const Circle& other) : radius(other.radius), color(other.color) {
        std::cout << "Circle 拷贝构造函数被调用，克隆半径: " << radius << std::endl;
    }

    std::unique_ptr<Shape> clone() const override {
        // 使用拷贝构造函数创建新对象
        return std::make_unique<Circle>(*this);
    }

    void draw() const override {
        std::cout << "绘制圆形，半径: " << radius << ", 颜色: " << color << std::endl;
    }
};

// 具体原型类：矩形
class Rectangle : public Shape {
private:
    int width;
    int height;
    std::string color;

public:
    Rectangle(int w, int h, const std::string& c) : width(w), height(h), color(c) {}

    // 拷贝构造函数
    Rectangle(const Rectangle& other) : width(other.width), height(other.height), color(other.color) {
        std::cout << "Rectangle 拷贝构造函数被调用，克隆宽度: " << width << std::endl;
    }

    std::unique_ptr<Shape> clone() const override {
        return std::make_unique<Rectangle>(*this);
    }

    void draw() const override {
        std::cout << "绘制矩形，宽度: " << width << ", 高度: " << height << ", 颜色: " << color << std::endl;
    }
};

// 客户端代码示例
// int main() {
//     std::unique_ptr<Shape> circlePrototype = std::make_unique<Circle>(10, "红色");
//     std::unique_ptr<Shape> rectPrototype = std::make_unique<Rectangle>(20, 30, "蓝色");

//     // 克隆对象
//     std::unique_ptr<Shape> clonedCircle = circlePrototype->clone();
//     std::unique_ptr<Shape> clonedRect = rectPrototype->clone();

//     clonedCircle->draw(); // 绘制圆形，半径: 10, 颜色: 红色
//     clonedRect->draw();   // 绘制矩形，宽度: 20, 高度: 30, 颜色: 蓝色

//     // 验证是否是不同的对象
//     std::cout << "原始圆形地址: " << circlePrototype.get() << std::endl;
//     std::cout << "克隆圆形地址: " << clonedCircle.get() << std::endl;
//     std::cout << "原始矩形地址: " << rectPrototype.get() << std::endl;
//     std::cout << "克隆矩形地址: " << clonedRect.get() << std::endl;

//     return 0;
// }

clone()

char*

new_obj.data = old_obj.data;

new_obj.data = new char[strlen(old_obj.data) + 1]; strcpy(new_obj.data, old_obj.data);

clone()

Shape

Circle

Rectangle

int

std::string

std::string

Circle(const Circle& other)

color

int* data;

data = new int[*size]; std::copy(other.data, other.data + *size, data);

clone()

clone()

selectedElement->clone()

std::map<std::string, std::unique_ptr<Shape>>

clone()