C++ Format for cout << Automatically

Question

If I had a simple class with two variables, x and y, and a function ToString() that returns a formatted string with the data. When I call

cout << simpleClass << "\n";

anyone know a way I could have simpleClass.ToString automatically called to return the correctly formatted string? I'm guessing there's a way to do this with operator functions, but I don't know how I would do this.

Answer 1

If you're asking how to define such an operator,

template<class CharT, class TraitsT>
std::basic_ostream<CharT, TraitsT>&
operator <<(std::basic_ostream<CharT, TraitsT>& os, SimpleClass const& sc)
{
    return os << sc.ToString();
}

Answer 2

You define

std::ostream& operator <<(std::ostream&, const SimpleClass&)

to call ToString(), passing the ostream&, and return the ostream&.