On Tue, Nov 29, 2011 at 6:19 PM, Darin Adler <da...@apple.com> wrote:
> On Nov 28, 2011, at 1:38 PM, David Kilzer wrote: > > In a discussion on Bug 71921<https://bugs.webkit.org/show_bug.cgi?id=71921>, > Antti, Darin Adler and I started a discussion about using C++ constant > pointers in WebKit. Does the WebKit community have a consensus opinion on > the matter? > > > I thought we were discussing local variables in general, not pointer-typed > ones specifically. > > * Pros > - Documents use of variable. > > > I would say “documents the fact that the variable’s value is not changed”. > I think it’s overstating things to say it “documents use”. > > - Prevents misuse of variable in a later patch (by a different author) > through enforcement of const-ness. > > > Prevents one specific type of misuse: Setting the variable to another > value. And that may not be misuse despite the fact that the original author > didn’t plan on changing it. > > - May help compiler optimize code. (We weren't sure whether modern > compilers do this on their own or not.) > > > Doesn’t. > > * Cons > - Darin Adler doesn't ever recall fixing a bug in WebKit where a > constant pointer would have helped. > > > While true, not really a “con”; just weakens the “pro” argument above that > this prevents misuse. > > - Slightly more verbose syntax for constant pointers to a constant > string (const char * const pointer;) or even a constant pointer to a > mutable string (char * const pointer;). > > > Not sure this is a con. Just stating what the C++ syntax. > > This is the con I am aware of: > > - Less brief than omitting const. > > I’m not strongly opposed to using const more, but I am mildly opposed to > it. > I can see your point of view. All of this seems to apply equally to const_iterator as well. Are you mildly opposed to it as well? Or is something different about it? Minor plug (which is why I happened this think about this): An additional current downside for const_iterator is that hashtable const_iterator has an unfortunate issue where it can't be compared ==, != to an iterator which isn't nice. https://bugs.webkit.org/show_bug.cgi?id=73370 dave
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