Re: [libvirt] [PATCH] util: Make virStringArrayHasString() const-correct
On Tue, 2016-08-16 at 18:49 +0200, Michal Privoznik wrote:
On 16.08.2016 13:40, Andrea Bolognani wrote:
>
> The first argument should be const char ** instead of
> char **, because this is a search function and as such it
> doesn't, and shouldn't, alter the haystack in any way.
>
> This change means we no longer have to cast arrays of
> immutable strings to arrays of mutable strings; we still
> have to do the opposite, though, but that's reasonable.
Is it? I mean, we are restricting ourselves and compiler fails to see
that. To me 'const char **' is more restrictive than 'char **' therefore
there should be no typecast required. But this is the discussion I
should have with gcc devels. For some reason, gcc does automatic
typecasting to const just for the fist level pointers and not the second
one. That's why compilers errors out.
The reason for this behavior is explained in the C FAQ:
http://c-faq.com/ansi/constmismatch.html
It's unfortunate, and very annoying. But I'd rather have
to perform arguably redundant casts than being bitten by
that kind of bug down the line :)
ACK
Pushed, thanks!
--
Andrea Bolognani / Red Hat / Virtualization