> On Aug 8, 2017, at 12:35 PM, Quincey Morris > <quinceymor...@rivergatesoftware.com> wrote: > > I don’t have a problem with using “new” vs. alloc/init, but there are a > couple of technical issues hiding behind this, though in current practice > they make little difference. > > 1. NSObject has “new” with a standard meaning. That means you can use “new” > on any subclass where it’s OK to use the simple “init” without parameters. > However, for classes that need parameters, or have multiple inits, there’s no > standard “newWithX:…” class method unless you provide it yourself. > > You can’t really provide this for Cocoa classes (you could try adding it via > a category, but this seems like a bad idea), which means your code uses a > mixture of strategies to create instances, even of the same class, depending > on the parameters needed. If that doesn’t bother you, fine. This is purely a > matter of preference. > > 2. In modern Obj-C, a class method beginning with “new…” is specially > meaningful to the compiler under ARC. By default, it has +1 ownership > semantics for the returned reference. Using Jens’ earlier example, that means > that the following are subtly different: > >> [NSArray array] // +0 semantics >> [NSArray new] // +1 semantics > > For custom “new…” methods, the declaration can override the default semantics > with a compile-time attribute, which means you cannot in general be certain > of the semantics without looking at the declaration. > > Of course, if the *calling* code is also ARC, then it doesn’t matter, because > ARC keeps track of the semantics for you.
Thank you. These concerns are exactly what I was looking for. Thanks for expressing them much better than I could. _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
