On Thu, Dec 4, 2008 at 12:53 AM, Stephen J. Butler <[EMAIL PROTECTED]> wrote: > On Thu, Dec 4, 2008 at 2:32 AM, EVS <[EMAIL PROTECTED]> wrote: >> Thank you, I suppose the reason I find it confusing is because self is a >> pointer to the current object. If self were to release self ( the current >> object ), while it is being used, I would have guessed that would cause >> problems. > > You can call [self release] as long as you don't access (directly or > indirectly) self for the rest of the method. So if you keep from > touching instance variables or calling methods off self then things > will be fine. And if your caller knows somehow (like checking return > values, in the case of init) to not reference the released self then > everything is kosher. > > In fact, the same is true in C++ with "this", only a little more > pathologically so. You're allowed to call non-virtual member functions > off a bad "this" pointer because
No, you're not. It is possible that many compilers will let you get away with it, but it doesn't mean that you're "allowed" to do it. > those functions are statically bound. > Causes confusion in every intro C++ course because students can't > figure out why their program is crashing in the middle of a method > call (when they finally access an instance variable off the bad "this" > pointer). > > I even saw a horrible design pattern, probably on The Daily WTF, where > the programmer was doing singletons via something like: > > ((MyClass*)NULL)->getInstance(); > > Totally pathological, but nothing technically wrong with it as long as > you're careful. No, according to the standard, that is undefined behavior. So not only pathological, it is also technically wrong :). -- Clark S. Cox III [EMAIL PROTECTED] _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
