Is this the correct way to overload the left-stream operator? (C++)

Question

This function declaration gives me errors:

ostream& operator<<(ostream& os, hand& obj);

The errors are:

error C2143: syntax error : missing ';' before '&'
error C4430: missing type specifier
error C2065: 'os' : undeclared identifier
error C2065: 'obj' : undeclared identifier
error C2275: 'hand' : illegal use of this type as an expression
    see declaration of 'hand'
error C4430: missing type specifier

hand is a class I made, display is a public data member of type char*.

Can anybody tell me what I'm doing wrong?

Answer 1

The declaration looks right. But the error message suggests that ostream is not known as a type. Try including the iostream header and say std::ostream instead.

Another thing you should consider is making the parameter 'hand' a const reference. So you could also accept temporaries and print them out.

Answer 2

is this inside a header? then you probably need to say std::ostream. Make sure you #include<iosfwd>.

Also, you can probably say const hand&.