Re: Quick syntax/compatibility question with libobjc2 and clang 3.4+

[David Chisnall]

Just incase anyone reads this in the mailing list archives:

On 29 Apr 2014, at 06:37, Kevin Ingwersen <ingwie2000@googlemail.com> wrote:

> The class isa is not defined, that I am pretty sure. But did you define 
> retainCount in your @interface too? I am reading this on a phone, by the way.

In modern dialects of Objective-C, you are permitted to declare private ivars 
within an @implementation context.  These are visible only via introspection or 
within the compilation unit where they are declared.  The runtime is 
responsible for laying out the object structures and defining the offsets.

> But from what I know in general is, that OS X uses a more modern version of 
> libobjc2 than the one gnustep ships. Not a big surprise, Apple hasn’t put 
> many open source updates so far, and if I am not mistaken, the version that 
> gnustep relies on is even older than 10.7 Lion.

This is 100% wrong.  The GNUstep runtime is a completely independent 
implementation.  It shares no code and very few design features with the Apple 
one.  It implements a superset of the features present in the latest Apple 
runtime (and implements several of the fast-path features measurably faster).

> Then again, I purely work on OS X…so i could be all wrong too.

Correct.

David

-- Sent from my brain