Nullable or Optional? Or something else?

[Andrei Alexandrescu]

grauzone wrote:
> Andrei Alexandrescu wrote:
>> I plan to add a Nullable struct to Phobos (akin to C#'s Nullable, 
>> Boost's Optional).
>>
>> Apparently a good design is to define Optional!T with a minimum of 
>> member functions (ideally none) and have it use the "alias this" 
>> feature to masquerade as a T. That way Optional!T looks and feels much 
>> like a T, except that it supports a function
> 
> I still don't understand how one can feel comfortable with the fact, 
> that "alias this" can overshadow arbitrary members of the alias'ed type.

That's why I want to add no member functions to Optional. The test for 
null will be a free function.

Andrei