@property needed or not needed?

[Maxim Fomin]

On Monday, 28 January 2013 at 12:31:35 UTC, Jacob Carlborg wrote:
> On 2013-01-28 12:44, Robert wrote:
>> @property use:
>>
>> I'd like to point out, that regardless of the "with 
>> parens/without
>> parens" stuff, marking properties with @property makes sense. 
>> So that
>> tools and frameworks can recognize them as such.
>
> I completely agree. I have created a struct called "attribute" 
> only to be used as an attribute for other types that should 
> only be attributes:
>
> struct attribute {}
>
> @attribute struct foo {}
>
> Even though @attribute in this case doesn't to anything it 
> shows the intent clearly. Same thing why I like explicit 
> interfaces and abstract classes compared with C++.
>
>> This also implies that
>> fields that are meant as properties should be declared 
>> @property and the
>> compiler should generate getter/setter so it behaves exactly 
>> like a
>> manually created property. May I add this to DIP21?
>>
>> Having the compiler lower the following:
>>
>> @property int a;
>>
>> to
>>
>> private int __a;
>>
>> @property int a() {
>> return __a;
>> }
>> @property int a(int new_a) {
>>   __a=new_a;
>>   return __a;
>> }
>
> I would love that. But the setter should return void and the 
> compiler should to property rewrites.

Returning void instead of int in the example break assignment 
chaining a = b = c. Besides, how such implicitly defined 
functions may call user defined code (check input validity, call 
events, etc.)?