C++ function returning by value can return rvalue reference?

I was reading up on rvalues and ran into something while trying a code snippet on compiler explorer. Here's a contrived example:

class A{    public:    A&& func(A& rhs)    {        //return rhs;        return std::move(rhs); //returning A&&    }};

vs

class A{    public:    A func(A& rhs)    {        //return rhs;        return std::move(rhs); //returning A&&    }};

I was expecting this second snippet to fail to compile because of return type mismatch. Func's return type here is A whereas what it's actually returning is A&& courtesy of std::move(). I have tried latest versions of gcc, clang and msvc. All have this same behaviour. Can someone please explain what's going on here?