Re: [Vala] GLib.List again

[Abderrahim KITOUNI <a kitouni gmail com>]

Hello,

2011/5/20, Jan Spurný <JSpurny seznam cz>:
> Hi,
>
> I have another question regarding manual writing VAPI files for existing
> C libraries using GLib.List. Now I have troubles with a method which acts
> similarly like many of the GList's methods - it takes "GList *" parameter
> and
> returns it's "new value" - which may or may not be the same as the given
> parameter, but it MUST be used.
>
> The only difference is that in my case the metod belongs to some
> other "Compact class" - so I can't use [ReturnsModifiedPointer] attribute
> and
> without it vala will think that return value is something new and at the end
> of the scope it will try to free them both. It looks like this:

I think this is something valac can't do for you, so you need to write
some ugly code: Using the same notation as your example, you'd need to
define your method as:

public GLib.List<X> run(owned GLib.List<X> list);

(owned tells valac that a value passed to this function doesn't need
to be freed) and then you call it as:

list = foo_bar.run ((owned) list);

(and if you forget the (owned) cast, you'll get an error telling you
to explicitly copy)

HTH,
Abderrahim