Re: [Vala] Using 'as' for casting?

[Jiří Zárevúcky <zarevucky jiri gmail com>]

On 08/07/2009 05:19 PM, Daniel Svensson wrote:
> When converting my application to use Gtk.Builder I ended up with a
> lot of code like this:
>
> var lbl = builder.get_object("foo") as Gtk.Label;
>
> And this caused me to try the following:
>
> var time = Time.gm (unxtime as time_t);
>
> as it was more readable than:
>
> var time = Time.gm ((time_t) unxtime);
>
> This however is not valid syntax, but maybe it should be? On IRC I got
> the answer that if an 'as' would fail it would return null, and that's
> why it shouldn't work.
>
> I thought it was best to drop a mail to the list and see what people think.
>
>    

That's right, but it's not just the fact it can return null. You can't 
use 'as' for simple types because there is no way to do run-time type 
check for them, so no way to find out whether cast is valid (until the 
segfault, of course). So there is no way 'as' could work for them.