From: Jeff King <peff@peff.net>
Date: Fri, 23 Jun 2017 19:12:24 GMT
Subject: Re: [PATCH v2 17/29] packed_ref_store: support iteration
Message-ID: <20170623191224.s5rkaruv6npbds7q@sigill.intra.peff.net>
In-Reply-To: <4171c4ea8b0280fa2c8cee9f1799933f66894f74.1498200513.git.mhagger@alum.mit.edu>

On Fri, Jun 23, 2017 at 09:01:35AM +0200, Michael Haggerty wrote:

> +static int packed_ref_iterator_advance(struct ref_iterator *ref_iterator)
> +{
> +	struct packed_ref_iterator *iter =
> +		(struct packed_ref_iterator *)ref_iterator;

I thought had some kind of safe downcasting mechanism for iterators, but
I think I was just thinking of files_downcast() for the ref-store.

I don't mind not having that kind of safety. It seems like an uncommon
error to call the packed-ref iterator function on the wrong type,
especially as it's static here and only accessible as a virtual function
for a packed_ref_iterator.

But something to think about, I guess, as we add more polymorphism.

-Peff