CPP13 — C++ ValueBox & Fixed question

Section 1.17.7.5 states: "Value boxes for these types [including Fixed]
map to classes that have exactly the same public interfaces as the
underlying boxed types...".

Does this also include overloaded operators that are defined in the
Fixed class?

It sure seems weird to allow some operators to work but not others:

// IDL
valuetype FixedVal fixed<5,2>;

// C++
FixedVal *fv = ...;

++fv; // legal?

CORBA::Fixed f = fv * 2; // illegal?