DIP26: properties defined

[Marco Leise]

Am Fri, 8 Feb 2013 22:13:45 -0500
schrieb Michel Fortin <michel.fortin at michelf.ca>:

> On 2013-02-08 23:53:30 +0000, Robert <jfanatiker at gmx.at> said:
> 
> > Ok. Here finally it is:
> > 
> > http://wiki.dlang.org/DIP26
> 
> This is pretty much exactly how I think properties should work. There's 
> two possible benefits you may to have overlooked…
> 
> One benefit of the "@property T foo;" syntax that does the boilerplate 
> code for you over using a plain variable: the getter and setter 
> generated are virtual in a class, so a derived class can override them. 
> Doesn't work with a plain variable.
> 
> Another possible benefit that we could have is the ability to use the 
> default getter but to provide your own setter implementation by just 
> declaring it:
> 
> 	@property int a;
> 	@property void a(int value) { __a = value; refresh(); }
> 
> Much cleaner than this:
> 
> 	private int _a;
> 	@property int a() { return _a; }
> 	@property void a(int value) { _a = value; refresh(); }
> 
> It's really great to not have to write boilerplate functions when 
> default behaviour is perfectly fine. I've been using Objective-C for a 
> while now and the recent changes where it automatically synthesize a 
> variable, a getter, and a setter when declaring a property (unless you 
> provide your own) are truly delightful.

There is only little think that itches me. In this example a
is an int. Would the setter always take a copy of a large
struct? I see no way to make it 'auto ref'!

-- 
Marco