Return a const reference or a copy in a getter function?

Question

What\'s better as default, to return a copy (1) or a reference (2) from a getter function?

class foo {
public:
    std::string str () { // (1)
              


        

Answer 1

1. if its a small basic type - primatives like int and long and their wrappers and other basic things like 'Point' - return a copy

2. if its a string, or any other complex type - return a reference.