Return Value Optimization and functions that build structures

I have a function that "builds" a structure to return:

struct stuff {
    int a;
    double b;
    Foo c;
};
stuff generate_stuff() {
    Foo c = generate_foo();
    //do stuff to Foo, that changes Foo:
    //...
    return {1, 2.0, c};  //should this be return {1, 2.0, move(c)};?
}

Should I be moving c out of the function? I realize that frequently, RVO can build the object in place, however there might be times when this ISN'T the case. When can't RVO be done, and thus, when should I move an object of a function?