Re: Extension of non-limited type needs limited component

[michael.jackson5@virgin.net (Mike)]

I originally wrote:

> > How can assignment by upcasting the extended type possibly affect the
> > limited component?
> 

Bob replied:

> If you have "type T2 is new T1 with...", then it is important that if T2
> is limited, then T1'Class must also be limited, because ":=" on T1'Class
> objects will copy the T2 part, if the objects' tag happens to be T2'Tag.
> 
> In Ada, T1'Class is limited if and only if T1 is limited.
> So that means the whole hierarchy of tagged types has to be
> either limited or nonlimited.  I'm not sure if it would cause semantic
> troubles to allow a nonlimited T1 with a limited T1'Class (assuming one
> could invent some syntax for saying so).  Interesting question.

Aha. That is the reason!

Thanks Bob,

Mike