What does this code do?

[DarknessCalling]

I've got a teacher who... well.. He's a fun guy, but he isn't the greatest teacher in the world. He gives us homework assignments designed so that we will all come up with basically the same code so his auto-grader can grade it. The assignments are generally half done already by him, and often use code that we students have no idea what it means. I can give more context for this code, but I doubt it'd help. This is from a class designed to handle complex number sets for a calculator that is supposed to work out simple math operations for complex number sets that include an imaginary part.

  istream& operator>>(istream &lhs,Complex& rhs) {
    rhs.real = 0;
    rhs.imagine = 0;
    return lhs;
}

[JLBorges]

See https://msdn.microsoft.com/en-us/library/x6aebccc.aspx