Objective-C 2.0 notes Edit

Created 11/3/2006, updated 3/12/2020

These notes are made on the basis of publicly available information:

Points for converting code to Objective-C 2.0 (with Garbage Collection):

self.var translates to [self var]
the synthezied instance variable generated based on the var property will be _var
if you want to access the instance variable directly you must therefore use self->_var or _var
var on its own will be a undeclared symbol error
you should avoid using accessors before an object is fully initialized (ie. in an init or copyWithZone: method)
in such cases use direct access (eg. self->_var)
with GC, retain/release et al are ignored
so your init methods should look like this:

- (id)init
{
    if ((self = [super init]))
        self->_var = [NSColor textColor];
    return self;
}

Note that there is no need to send a retain to the returned color
Also note that when properties are used there is no need to declare instance variables, accessor methods, or write accessor methods
A suitable property declaration in the header would be:

@property (ivar) NSColor *fooColor;

The ivar attribute tells the compiler to add an instance variable (in this case, _fooColor) and accessor methods (fooColor and setFooColor:)
There is no need for a dealloc method; the color will be deallocated when all references to the object go away
Implicit accessor methods are presumably sensitive to whether they are used as a left-hand or a right-hand value in an assignment:

// presumably equivalent to: [object setName:@"foo"]
object.name = @"foo";

// presumably equivalent to: var = [object name]
var = object.name;

Is Objective-C 2.0 available?

Check for built-in macro, __OBJC2__?