完整教程：【设计模式】适配器模式

概念

结构型模式

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类图

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代码

#include <iostream>
  #include <math.h>
    using namespace std;
    class RoundPeg
    {
    public:
    RoundPeg() = default;
    explicit RoundPeg(int r) : radius(r) {
    }
    virtual ~RoundPeg() = default;
    virtual int GetRadius() const {
    return radius;
    }
    private:
    int radius;
    };
    class RoundHole
    {
    public:
    explicit RoundHole(int r) : radius(r) {
    }
    virtual ~RoundHole() = default;
    virtual int GetRadius() const {
    return radius;
    }
    string Fits(const RoundPeg* roundPeg) const {
    if (this->
    GetRadius() >= roundPeg->
    GetRadius()) {
    return "True\n";
    } else {
    return "False\n";
    }
    }
    private:
    int radius;
    };
    class SquarePeg
    {
    public:
    explicit SquarePeg(int w) : width(w) {
    }
    ~SquarePeg() = default;
    virtual int GetWidth() const {
    return width;
    }
    private:
    int width;
    };
    class SquarePegAdapter
    : public RoundPeg {
    public:
    explicit SquarePegAdapter(SquarePeg* squarePeg) {
    this->squarePeg = squarePeg;
    }
    int GetRadius() const override {
    return squarePeg->
    GetWidth() * sqrt(2) / 2;
    }
    private:
    SquarePeg *squarePeg;
    };
    int main(int argc, char *argv[]) {
    auto roundHole = new RoundHole(5);
    auto roundPeg = new RoundPeg(5);
    cout << roundHole->
      Fits(roundPeg);
      delete roundPeg;
      auto sSquarePeg = new SquarePeg(5);
      auto lSquarePeg = new SquarePeg(10);
      // cout << roundHole->Fits(sSquarePeg); // type is diff
        auto sSquarePegAdapter = new SquarePegAdapter(sSquarePeg);
        auto lSquarePegAdapter = new SquarePegAdapter(lSquarePeg);
        cout << roundHole->
          Fits(sSquarePegAdapter);
          cout << roundHole->
            Fits(lSquarePegAdapter);
            delete sSquarePegAdapter;
            delete lSquarePegAdapter;
            delete sSquarePeg;
            delete lSquarePeg;
            delete roundHole;
            return 0;
            }
            ```