Question

#include <string>
#include <iostream>

template <typename T>
T max(T a, T b) {
    return a > b ? a : b;
}

class Dummy {
  private:
    std::string name;
    int age;
  public:
    Dummy(int an_age) {age = an_age;}
    bool operator> (Dummy &a) {return age > a.age;}
    std::string toString() const {return "The age is " + age;}
};

std::ostream& operator<<(std::ostream& out, const Dummy& d) {return out<< d.toString();}

int main()
{

  std::cout << max(3, 7) << std::endl;

  std::cout << max(3.0, 7.0) << std::endl;

  std::cout << max<int>(3, 7.0) << std::endl;

  std::cout << max("hello", "hi") << std::endl;

  Dummy d1(10);
  Dummy d2(20);
  std::cout << max(&d1, &d2) << std::endl;

  return 0;
}

I’m pretty new to C++ but not new to programming. I’ve written the code to play with template and operator overloading in C++.

It took quite a while to make it compile and partially work.

1. The ostream operator<< is not working properly, only to return the address of the object. I can’t figure out the causes.

2. I managed to make it compile by blind trial and error, so I suspect the code might be broken to some extent. And I may not be aware of what’d be improved.

Answer 1

Your max(&d1,&d2) expression gives you the address, and that is printed out. Your operator overloading is fine.