Re: Derived private interface

[Stephen Leake <stephen_leake@stephe-leake.org>]

AdaMagica <christ-usch.grein@t-online.de> writes:

> On 6 Jul., 09:55, Georg Bauhaus <rm.dash-bauh...@futureapps.de> wrote:
>> On 7/6/11 6:34 AM, AdaMagica wrote:
>>
>> > I should have written
>>
>> >    overriding procedure Doit (X: access Derived_Class);
>>
>> Instead of sprinkling the program with overriding indicators,
>> shouldn't it be normal for a compiler to detect the status of
>> a subprogram WRT overriding? (It is, I think, and not just in
>> Ada.) Consequently, programmers would mark the opposite case.
>> They'd write "not overriding" only if a subprogram is really
>> intended to not be overriding.
>
> OK, the compiler knows what it is - but the programmer perhaps
> doesn't. It is a hint for the compiler to check the programmer's
> intention.
>
> overriding: the compiler complains - oops, did I misspell the name?
> non overriding: the compiler complains - oops, I thought there was an
> inherited version.

More importantly; oops, I changed the parent, and forgot to change the
child; now the compiler warns me.

If you don't put 'overriding' on all child operations, they silently
become non-overriding when the parent changes. Very Bad Things Happen.

-- 
-- Stephe