Re: Inherited Methods and such

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Maciej Sobczak <see.my.homepage@gmail.com> writes:

> The above program prints 0 as the value of an object which type is
> range 10 .. 20.

Well, it happens to print 0 in one implementation.
According to the RM, this is a bounded error, and
it could just as well raise an exception (or print
some other bogus value).

Is this something fundamentally broken about constructors,
or is just another case of uninitialized variables?
I mean, there are lots of other ways to create uninit vars
in Ada...

> What's even more funny, I can add the following inside Some_Operation
> for S:
>
> declare
>    J : R := X.I;  -- at this point X.I = 0
> begin
>    Put (R'Image (J));
> end;
> 
> Guess what will happen. No constraint_error and 0 is assigned to J.
             ^^^^ might

> Why? Because the poor compiler assumed that if X.I is of type R, then
> no checks are necessary.

Right.  Or it might raise an exception.  I don't find this "more funny"
-- it's equally funny as the previous case of printing 0.

- Bob