Method definite_info

See comment in RustStruct::definite_info(), this is the same, returns a string expression which evaluates to the length. self_expr is an expression that evaluates to this RustType (e.g. member, etc) at the point where the return of this function will be used. self_is_ref whether the above expression is by-ref

(
        &self,
        self_expr: &str,
        self_is_ref: bool,
        types: &IntermediateTypes,
        cli: &Cli,
    )