From: Jacek Caban <jacek@codeweavers.com>
Subject: Re: [1/2] jscript: Support PROPERTYGET in Date Value
Message-Id: <548DC089.7080306@codeweavers.com>
Date: Sun, 14 Dec 2014 17:53:29 +0100

On 12/14/14 00:18, Alistair Leslie-Hughes wrote:
>     case INVOKE_PROPERTYGET:
> +    {
> +        DateInstance *date;
> +
> +        if(!(date = date_this(jsthis)))
> +            return throw_type_error(ctx, JS_E_DATE_EXPECTED, NULL);

It's guaranteed that jsthis is of DataInstance type in case of *_value
functions, so there is no need to check that in runtime. You may simply
cast it here.

Jacek