On Tue, Aug 16, 2016 at 07:55:11PM +0200, Andrea Bolognani wrote:
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
Just FYI, so that you know why adding more consts (even to sensible places) doesn't help in C, I found the answer to my question on stack overflow [1] very satisfactory and explanatory. Martin [1] https://stackoverflow.com/questions/35319842/why-c-doesnt-allow-implicit-conversion-from-char-to-const-char-const-and
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 :)ACKPushed, thanks! -- Andrea Bolognani / Red Hat / Virtualization -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
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