Filip, at that point we should step away from the mutable/const sort
of manual management style. Perhaps something like:

> mutable (const int x = 0) {
> // x is a non-const lvalue within this block for the purpose of initialization
> }
> // x is an lvalue of type const int, but it is not a const object
>
> // if x was a class type, the move constructor would be called here because we lift constness
> // for the purpose of return or throw
> return x;

I much prefer this "RAII const management" over the "manual const management".

However, even then, you can achieve a very similar (scoped) effect by
using a do expression as the initializer of x.