【C++ Primer | 14】重载运算

重载（）运算符

 

#include <iostream>
using namespace std;

class Distance
{
private:
  int feet;   // 0 到无穷
  int inches; // 0 到 12
public:
  // 所需的构造函数
  Distance()
  {
    feet = 0;
    inches = 0;
  }
  Distance(int f, int i)
  {
    feet = f;
    inches = i;
  }
  // 重载函数调用运算符
  Distance operator()(int a, int b, int c)
  {
    Distance D;
    // 进行随机计算
    D.feet = a + c + 10;
    D.inches = b + c + 100;
    return D;
  }
  // 显示距离的方法
  void displayDistance()
  {
    cout << "F: " << feet << " I:" << inches << endl;
  }
};
int main()
{
  Distance D1(11, 10), D2;

  cout << "First Distance : ";
  D1.displayDistance();

  D2 = D1(10, 10, 10); // invoke operator()
  cout << "Second Distance :";
  D2.displayDistance();

  return 0;
}

重载->运算符

#include <iostream>
using namespace std;

class A
{
public:
    void display() { cout << "yes,ok" << endl; }
};

class P
{
public:
    P(A& ra) :ptr(&ra) {}
    A* operator->() { return ptr; }
private:
    A* ptr;
};

class PP
{
public:
    PP(A& ra) :p(ra) {}
    P operator->() { return p; }
private:
    P p;
};

int main()
{
    A a;
    P p(a);
    p->display();

    cout << endl;

    PP pp(a);
    pp->display();
    return 0;
}