Operator overload << error

Question

Im trying to overload the operator <<

const ostream & operator<<(const ostream& out, const animal& rhs){
    out << rhs.a;
    return out;
}

it seems im getting an error because im returns a constant, and also because the first argument is const refrence for the ostream object.

cout << objectOfAnimal1 << objectOfAnimal2 ;

It works fine if I change the return type and the operator signature to this:

ostream & operator<<(ostream& out, const animal& rhs)

+3

Alexdan May 03 '12 at 15:43

2 answers

ostream & operator<<(ostream& out, const animal& rhs){
out << rhs.a;
return out;
}

You have already explained what is the probable cause of the problem, and you really have not tried it?

+1

Griwes May 03 '12 at 15:45

Alok save · Accepted Answer · 2012-05-03T15:45:59+0000

You need:

ostream & operator<<(ostream& out, const animal& rhs)

In the code, you are trying to modify the object const ostreamand you will get errors.
It should not be const.