property functions

[Nick]

On Sunday, 16 May 2021 at 15:47:55 UTC, Adam D. Ruppe wrote:
> On Sunday, 16 May 2021 at 15:12:25 UTC, Nick wrote:
>> Is this warning still valid?
>
> The @property thing doesn't do much. All it does is change 
> typeof(a.prop) from function over to the return value of the 
> function. (Which actually makes it required for the range empty 
> and front things!)
>
> But since it doesn't do much it makes it very easy to misuse it 
> too - putting it somewhere where it doesn't belong will NOT 
> cause the compiler to issue an error.
>
> So that's why it is warned: the current behavior is extremely 
> minimal and if that expands and you misused it, you'll see 
> broken code down the line.
>
> But on the other hand, @property has been a do-nothing for a 
> decade now, so I wouldn't expect that to change any time soon.
>
> My general rule is to put it on something that should be 
> replaceable with a public data member. If you can't do that, 
> don't make it @property. In particular, do NOT put it on 
> something for the sole reason of not using () on the call. 
> @property is not really related to parenthesis syntax. Only use 
> it when it is specifically meant to be replaceable with a 
> public member.

Thanks for the detailed explanation. I guess the wording of the 
warning seems strange to me, in that it recommends not to use 
property functions; but, in actuality (and regardless?), these 
functions are used a lot (even in the standard library; at least 
from what I've seen). Also, although this warning is delivered, 
there is nothing in the documentation that explicitly addresses a 
concrete downside (or recommended limitation) to using them. 
However, your explanation does provide some context to this 
warning.