Re: [Vala] Converting nullable to non-nullable types

[Jiří Zárevúcky <zarevucky jiri gmail com>]

Sam Wilson píše v Čt 25. 02. 2010 v 18:07 -0500:
> Hey!
>
> I am just wondering if there is any syntactic sugar for shortening the
> following code segment
>
> [code]
> Element? nsource = ElementFactory.make("filesrc", "file-source");
> if (nsource == null) { printError(); return; }
> Element source = (Element)nsource;
> [/code]
>
>
> To me, it seems like a common pattern to convert a nullable type to a
> non-nullable type.  If such a shortcut does not exist, perhaps it would
> be a good idea to add a "conditional cast" operator

Here's a little trick you might like:

[code]

errordomain MyError {
        FAILED;
}

T throwerror<T> (string str) throws Error {
        throw new MyError.FAILED (str);
}

int func ()
{
        int? i = null;
        int j = i ?? throwerror<int> ("hello");
        return j;
}

[/code]

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