Re: [Outreachy] [PATCH] blame: Convert pickaxe_blame defined constants to enums

From: Jonathan Tan <jonathantanmy@google.com>
Date: Oct 14, 2019, 18:27 UTC
Message-ID: <20191014182754.82302-1-jonathantanmy@google.com>
In-Reply-To: <xmqqk19ag60g.fsf@gitster-ct.c.googlers.com>

Show 14 quoted lines

> Jonathan Tan <jonathantanmy@google.com> writes:
> 
> >> > Also, I have a slight preference for putting "= 02" on the BLAME_COPY
> >> > line but that is not necessary.
> >> 
> >> That is absolutely necessary; it is not like "we do not care what
> >> exact value _COPY gets; it can be any value as long as it is _MOVE
> >> plus 1", as these are used in set of bits (and again, I do not think
> >> it is such a brilliant idea to use enum for such a purpose).
> >
> > Good point.
> 
> Doesn't that also show that enums are not quite a good fit for set
> of bits (i.e. 1<<n)?

Well, I agree that it could be better, but with the C language as we have it now, I still slightly prefer an enum to a list of #define. Both ways, we still have to manually enter values for each flag, but with enum, we get better debugger display (at least in gdb) and in the function declaration and definition, we can put a specific type (instead of "unsigned" or "int"). gdb supports the notion that a few people use enums this way too, but if we decide as a project to not use enums in this way, that's fine too. For what it's worth, I tried doing a search online, but most of the results I got was for C# (where it is recommended - they have a "[Flags]" attribute for enums), so maybe I am indeed in the minority.