Implications of using an ampersand before a function name in C++?

Question

Given the example:

inline string &GetLabel( ) {
        return m_Label;
};

Where m_Label is a private class member variable.

Answer 1

The ampersand isn't before the function name so much as it's after the return type. it returns a reference to a string.

The implication of this is that a caller of this function could modify the value of m_label through the reference. On the other hand, it avoids copying the string. You might want the reference and the function to be const, like so:

inline const string& GetLabel() const
{
    return m_Label;
}

Best of both worlds. You avoid the copy, but callers can't change your object.