Re: Pb with use of redefined "=" operator

[Robert A Duff <bobduff@world.std.com>]

dewarr@my-dejanews.com writes:

> There is of course the currently fashionable code-bloat style of programming
> where no one cares if their programs run slowly and take up too much memory,
> but the trouble is that if you write standard packages in this style, it very
> much restricts the uses they can be put to...

I very much agree with the above (I hate buying new hardware that's 2
times faster, and then finding that it's only 1.1 times faster in
practise because the new software that goes with it makes up for the
speed gains), but:

>...(in many embedded and safety
> critical applications, tagged types are eliminated for good reasons!)

I disagree with that part.  Making a type tagged adds one word of
storage to each object of the type, in typical implementations of Ada.
It's quite easy to decide on a case-by-case basis whether that's "too
much".

There might be reasons to forbid the 'Class attribute in certain
safety-critical applications, but I see no reason to forbid "tagged".
Tagged types (without 'Class) don't introduce any dynamic dispatching or
anything else that might be of concern.

I've heard some safety-critical folks talking about not using "tagged"
because it introduces dynamic dispatching.  But that's a
misunderstanding of the language -- if you want to prevent dynamic
dispatching, then forbid 'Class.

- Bob
-- 
Change robert to bob to get my real email address.  Sorry.