`X::X(const X&&)` Const Move Constructor? [duplicate]

Question

Possible Duplicate:
Move constructor signature

struct X
{
    X(X&);         // (1)
    X(X&&);        // (2)
    X(const X&);   // (3)
    X(const X&&);  // (4)
};

Are there any situations where (4) will be picked in overload resolution?

Answer 1

Yes. One situation is when you have a function with a const return value:

const X f();

X x(f());