Does NSFileHandle -readDataOfLength: return autoreleased NSData?

Question

When I call readDataOfLength: on an NSFileHandle instance, do I need to release the returned NSData? Currently I'm not, but I would like to get rid of this nagging doubt.

Answer 1

Nope. Cocoa's memory management rules say that you only own (and thus need to release) objects returned from a method whose name contains one of "new", "alloc", "retain", or "copy" (NARC). Since that method contains none of those, you know you don't need to release it.

Answer 2

The standard that is observed very consistently within Objective C libraries is that a method beginning with "alloc" or "copy" (and, I'm thinking, some other obscure verb) returns a retained object, while everything else returns an autoreleased object.

Any exceptions should be well-documented in the specs.