Re: Problem with protected type

["Ekkehard Morgenstern" <ekkehard.morgenstern@onlinehome.de>]

"Jeffrey Carter" <spam@spam.com> schrieb im Newsbeitrag
news:uPMwb.14566$n56.8738@newsread1.news.pas.earthlink.net...
> > The compiler reports "premature usage of incomplete type derived from
> > "BaseEvent"".
>
> That's not a great error message.

That's true, because CoreEvent is not derived from BaseEvent. I already
figured it had to do with the CoreEvent component instantiation, but the
message is strange indeed.

> I suspect that your real problem is that you omitted the word "type"
> between "protected" and "Baseevent". "protected Baseevent" declares a
> single protected object; "protected type Baseevent" declares a type
> which may then be used to declare many objects of the type.

Thank you! I completely overlooked that! ;-)

> A type declaration may include a reference to an incomplete type, such
> as Coreevent. An object declaration may not, since it has to allocate
> space for the components, and the compiler does not yet know how much
> space needs to be allocated for Coreevent.

Ok. It's clear to me now! :-)

I thought I was creating a type, not a object. But of course it seems
logical that "type" would be required to designate a type. ;-)

> > Can I use a barrier expression that is doing a function call?
>
> Yes, a barrier can be any boolean expression. If you limit yourself to
> the Ravenscar profile, however, a barrier must be a Boolean component of
> the object.

What is the Ravenscar profile?  And why would a barrier be limited to a
Boolean component then?

> BTW, I find the Ada way, Base_Event, much easier to read than Baseevent,
> which is what my reformatter does with your kind of identifiers.

Ok. I can change it, I always fear I clash with predefined names, and
thought the contracted version would be less a candidate for that.

But as far as I understand, the default namespace includes only the Standard
package, right?

BTW, are there any predefined Lists, Queues, Events, Message Queues, and
Containers I could use? I didn't find anything in the Ada 95 reference.