Return: Quiz IV in C++

Quiz: What would this code produce if we were to copy-paste it in a code editor and run it?

string greetAndReturn() {
    return "How are you doing?";
    cout << "Hey bro!" << endl;
}

void mainFunction() {
    string question = greetAndReturn();
    cout << question << endl;
}

Important Note:

Do not use an actual code editor to get the answer! It would defy the whole purpose of the quiz!