From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 10 Mar 2020 18:19:33 GMT
Subject: Re: [PATCH] commit-slab: clarify slabname##_peek()'s return value
Message-ID: <xmqqftegjcne.fsf@gitster.c.googlers.com>
In-Reply-To: <20200310175446.GB549010@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

> But that would get a bit awkward, because peek() returns a pointer, not
> a value (as it should, because the type we're storing may be a compound
> type, which we generally avoid passing or returning by value).  So we'd
> actually need to return a pointer to a zero-initialized dummy value. Not
> impossible, but getting a bit odd.

Do we have a guarantee that callers of the peek only look at, never
touch, the location?  As long as we make it return a "const *", it
might be OK, but a quick look at commit-slab.h tells me that we do
not say "const".