Re: [Vala] out, ref and GError parameters.

[Jürg Billeter <j bitron ch>]

On Don, 2007-03-15 at 22:02 -0300, Alexandre Moreira wrote:
> On 3/15/07, Jürg Billeter <j bitron ch> wrote:
> > It should work as follows:
> >
> > Method definition
> >         public void test (out Error error) {...}
> >
> > Checking for null
> >         if (out error != null) {...}
>
> The problem with that is that it generates the following code:
>
> if (&(*error) != NULL) { ... }
>
> and this means that error will be dereferenced and then turned back
> into an address... Oh well, wait. I just decided to take a look at a
> debugger before hitting send.
>
> The thing is, I read the generated code but never actually ran it. It
> looks like by some kind of black magic (either that or I really don't
> get the meaning of that statement) error never gets dereferenced, even
> with the dereference operator acting right in front of it.
>
> I don't know if this is compiler dependent though. Perhaps it is
> simply a matter of gcc being smart enough to identify the pointless
> mix of operations and ignoring both.

It's obviously not nice code but it's only temporary and I assume it
works with any compiler as dereferencing error in &(*error) wouldn't
make sense.

> Just to be sure, though: Is the pointer support anywhere in the "map
> of plans" ? If so, is it near or far from being implemented (based on
> your list of priorities).

Yes, we'll add pointer support. I'll try to add it in the next couple of
weeks if it won't require large changes.

Jürg