DIP23 draft: Fixing properties redux

[Timon Gehr]

On 02/04/2013 03:38 PM, kenji hara wrote:
> 2013/2/4 Andrei Alexandrescu <SeeWebsiteForEmail at erdani.org
> <mailto:SeeWebsiteForEmail at erdani.org>>
>
>
>     Couldn't AddressOf use "&(" + exp + ")"?
>
>
> Yes. It's enough. I wanted to explain that "we should treat
> address-expression carefully".
>
>     I thought more about this. The problem remains even without
>     @property, due to optional parens in function invocation. Consider:
>
>     ref int fun() { ... }
>     auto p1 = &fun;
>     auto p2 = &(fun);
>     auto p3 = &(fun());
>
>     What are the types of the three? The optional parens in invocation
>     require some disambiguation. I think the sensible disambiguation is
>     to have &fun take the address of fun and the other two take the
>     address of fun's result.
>
>
> Agreed.
>

Why?

>     I would agree restricting the properties, but requiring a __trait to
>     take the address of a regular function or method seems overkill.
>
>
> Fully agreed.
>

It is not an interesting point. It is not necessary anyway.

> Although it looks strange and unstable, adding new distinction of
> semantics between &foo and &(foo) has no ambiguity.
>

It _is_ strange.

> I think this is necessary feature for the D's function and property
> semantics.
>

Why?