Nullable or Optional? Or something else?

[Andrei Alexandrescu]

Jarrett Billingsley wrote:
> On Wed, Sep 2, 2009 at 4:13 PM, Simen Kjaeraas<simen.kjaras at gmail.com> wrote:
>> Danny Wilson <bluezenix at gmail.com> wrote:
>>
>>> Op Wed, 02 Sep 2009 21:39:28 +0200 schreef Andrei Alexandrescu
>>> <SeeWebsiteForEmail at erdani.org>:
>>>
>>>> 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
>>>>
>>>> bool isNull(T)(Optional!T value);
>>>>
>>>> Am I on the right track? If so, what is the name you'd prefer for this
>>>> artifact?
>>>>
>>>>
>>>> Andrei
>>>
>>> How about:  Maybe!T
>>>
>>>
>>> Got that from Haskell :-)
>> I also feel the bikeshed should be colored 'Maybe'.
> 
> Thirded!

Great. Now, before we get all jolly about Maybe, let me point out that 
we also need the "ref" corresponding type. And OptionalRef and 
NullableRef may sound better to some than MaybeRef.

Andrei