references(&int a, &int b, () r)
{
	/* don't have assignment and not quite sure if I want to have to
	 * dereference references so I guess we can't really do much here at the
	 * moment, heh */
	 r();
}

main()
{
	20 => int twenty;
	30 => int thirty;
	references(twenty&, thirty&) => {
		20 + 30 => int fifty; /* ok */
	};

	/* references are not active anymore so we can reference again */
	references(twenty&, thirty&) => {
		/* Try uncommenting!
		 * Not ok since twenty/thirty is actively borrowed
		 */
		// twenty + thirty => int fifty;
	};
}