Overloading cout and cin for class objects?

[Search_not]

How do I overload the cout and cin operators so as to get input and show output using an object?

Heres a simple example of what I'm trying to do:

class Temp{
    double fTemp;

    public:
        double FahrToCelsius(double fTemp){
            return (fTemp - 32.0) / 1.8;
        }

        friend std::ostream operator<<(std::ostream Out, const Temp& tempVar);  //overloading of the ostream "cout"

        friend std::istream& operator>>(std::istream& In, Temp& tempVar);   //overloading of the istream "cin"   
}

//using namespace std
int main(void){
    Temp tempVar;   //create object

    cout << "Enter fahrenheit temp: " << endl;
    cin >> tempVar;

    cout << "Fahrenheit Temp: " << tempVar.FahrToCelsius(tempVar);

  return 0;
}

Am I doing it wrong or is there a way to overload the operators?

[Moschops]

I think this might be what you're trying to do. Note that in your code, you wrote declarations for the overloaded operators, but you didn't actually write any code for them.

#include <iostream>

using namespace std;

class Temp{
  double fTemp;
    public:

        double FahrToCelsius(){
            return (fTemp - 32.0) / 1.8;
        }
        friend std::ostream operator<<(std::ostream Out, const Temp& tempVar);  //overloading of the ostream "cout"
        friend std::istream& operator>>(std::istream& In, Temp& tempVar);   //overloading of the istream "cin"   
};


istream& operator>> ( istream& is, Temp& obj )
{
   is >> obj.fTemp;
   return is;
}

ostream& operator<< ( ostream& os, Temp& obj )
{
   os << obj.FahrToCelsius();
   return os;
}


int main(){
    Temp tempVar;   //create object
    cout << "Enter fahrenheit temp: " << endl;
    cin >> tempVar;
    cout << "Fahrenheit Temp: " << tempVar;
  return 0;
}

Note that when this code applies an object of type Temp to the overloaded << operator, what's actually happening is a call to the object's FahrToCelsius function. If this is what you wanted, that's great; it's a bit overkill for this actual case, and also counter-intuitive. If you really wanted to do this, I wouldn't bother with the overloading of the << operator and I wuold simply call the object's function myself:

cout << obj.FahrToCelsius();

[Search_not]

Thanks a lot! Would it be possible to do the same thing with enum types as well? excluding the object of course

[Moschops]

It's possible to do it with anything you like. If you did it with an enum type, you'd presumably be taking in a string or an int, and you'd need to write the code to interpret that string or int and set the appropriate enum value in your class (or just plain enum).

[Search_not]

Okay, thanks again for the help!