概念
结构型模式
类图
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 diffauto 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;}```