Re: Dispatching in Ada95

[jsa@organon.com (Jon S Anthony)]

In article <317BCF1F.6542@csehp3.mdc.com> "James A. Squire" <m193884@CSEHP3.MDC.COM> writes:

> > You're right in saying that it will check a subprogram which is
> > directly visible (if you don't give a prefix). But if your parameter
> > is of a class-wide type, only a subprogram with the base type of this
> > class-wide type needs to be visible.
> 
> Correction:  Directly visible.

Correction, not directly visible.  And dispatching has nothing to do
with visibility anyway.  Why do you think so??????


> > Now, our main procedure T. T withes AAA, BBB and Text_IO, and uses all
> > of them except BBB.
> 
> So, you do compromise and use the use clause, then.  That was my whole
> question.  The use clause *is* essential to dispatching.

No.  Not only is the use clause _NOT_ essential, it has nothing to do
with it.  Dispatching is a runtime thing based on the dynamic type
(tag) of the operands of the particular invocation.  You're just plain
confused (for some reason...)


> Thank you for answering my question.  Just another "gotcha" of Ada95 to
> note for future reference.

Unfortunately, you still don't get it.  There is no "gotcha" here.

/Jon
-- 
Jon Anthony
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