Re: Issue with GNAT GPL 2009 and GtkAda

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

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
news:1hi0km5xe1802.17l3qjn1g9525$.dlg@40tude.net...
...
> I would remove anonymous access types altogether, fixing the real language
> problems, which led to introducing them in first place.

I don't think that there were any *real* language reasons for introducing 
them; the reasons came from wanting to make Ada more appealing to C and Java 
programmers. (A horrible reason for language design, IMHO.) They can be used 
to work around some of Ada's other limitations.

In any case, it appears likely that Amendment 2 will repeal the prohibition 
on "in out" parameters on functions (adding a conservative call check to 
prevent obvious ordering dependencies).

We're also planning on adding a way to force by-reference parameter passing. 
The motivating use is for the containers, but I'm sure it will find other 
uses as well.

As far as the use of class-wide components, I think that would be easily 
fixed by just allowing them. They would be fairly easy to implement in 
Janus/Ada. (I'd also make it required to support any size of discriminant, 
banning max-size only implementations). But I realize that that would be a 
problem for safety-critical uses (there would be implicit allocation on some 
assignments), so we'd also need a fairly strong set of restrictions for such 
users.

That would reduce the need to use access types some more. (But it can never 
be completely eliminated; sometimes you really do need reference semantics, 
especially for returns.)

                                              Randy.