Re: Reprise: 'in out' parameters for functions

["Randy Brukardt" <randy@rrsoftware.com>]

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message
news:c5b6pt$2pcs4d$2@ID-77047.news.uni-berlin.de...
...
> Provided that:
>
> 1) protected object and tasks would be tagged (inheritable from);
> 2) multiple inheritance would be supported;
> 3) entries, procedures and functions would be primitive operations;
> 4) functional notation would be permitted (instead of prefix notation)

See AI-345, which extends the interface mechanism (itself a Ada 200y
proposal) to cover task and protected types. (1) is true if the PT or TT
inherits from one or more interfaces; (2) follows from the definition of
interfaces; (3) is true for calls through interfaces (as opposed to directly
to the PO or TOs); (4) is true for calls through interfaces.

> one could have entries of multiple protected objects and tasks.

I don't see how this follows from (1) to (4), though. Each call is just a
dispatching call to a single operation; there is no implementation
inheritance.

> A call to such entry would start multiple protected actions (one per each
protected
> object parameter) and multiple rendezvous (one per each task object
> parameter). Could we agree that 1-4 is a damn *lot* of work?

Not really. *Interfaces* is a lot of work, but presuming that we're going to
have those anyway, adding protected and task support to them is not a
significant increment.

                 Randy.