Re: [Vala] A struct in a vapi file with undefined contents?

[Tal Hadad <tal_hd hotmail com>]

It's sounds like what you want is a compact class:
[CCode (cname = "FIT_CONVERT_STATE")]
[Compact]
public class a {
}

Compact class is better, since it's always treated like pointer.
In struct you may accidentally copy memory(zero in your case) if you do
a value assignment.

Tal

> From: dylanmccall gmail com
> Date: Mon, 29 Jul 2013 23:37:03 -0700
> To: vala-list gnome org
> Subject: Re: [Vala] A struct in a vapi file with undefined contents?
>
> And, naturally, if I'd just not made a silly typo when I had tried
> this, I would have seen valac doesn't complain at all and it works the
> way I want, allocating the correct space in memory. Hooray!
>
> So, I have the following in my vapi file now…
>
> [CCode (cname = "FIT_CONVERT_STATE")]
> public struct State {
> // Private
> }
>
> Sorry about the noise. Of course, please do point out if this is going
> to end poorly :)
>
> --
> Dylan
>
> On 28 July 2013 22:28, Dylan McCall <dylanmccall gmail com> wrote:
> > Sometimes, when I find myself working with a (plain) C library through
> > Vala, I end up using a pattern like this. I really don't like it:
> >
> > void * convert_state = Fit.create_convert_state();
> > Fit.Convert.init(convert_state, true);
> >
> > In this case, Fit.Convert.init is part of the original library, which
> > I made a vapi file for. It takes a reference to convert_state, which
> > it writes to. Fit.create_convert_state() is a function I created in a
> > small C wrapper library. The entire point of it is to allocate space
> > for a struct on the heap (for Fit.Convert.init), and then return a
> > pointer to that struct. The struct isn't in the vapi file because it's
> > huge and complicated and it's really internal to that library. Its
> > contents aren't _interesting_ to the Vala program - just that it's of
> > a particular size.
> >
> > Is there a way to add a struct with undefined contents in a vapi file?
> > That way I can maybe do something like this with the example?
> >
> > ConvertState convert_state = ConvertState();
> > Fit.Convert.init(convert_state, true);
> >
> > We wouldn't be able to access any members in convert_state, but we'd
> > be spared ugly void pointers.
> >
> > …or am I looking at this the wrong way? I probably am. Any help is
> > appreciated :)
> >
> > --
> > Dylan
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