Option!T

[deadalnix]

On Tuesday, 10 December 2013 at 19:26:27 UTC, Andrei Alexandrescu 
wrote:
> On 12/10/13 10:59 AM, monarch_dodra wrote:
>> On Tuesday, 10 December 2013 at 17:28:26 UTC, Andrei 
>> Alexandrescu
>> wrote:
>>> We have only(x) 
>>> (http://dlang.org/phobos/std_range.html#.only) to be a
>>> collection of exactly one value, but not a type for "a value 
>>> of type T
>>> or nothing at all"
>>
>> Option is being upgraded to handle an arbitrary (but compile 
>> time
>> known) amount of values:
>> https://github.com/D-Programming-Language/phobos/pull/1743
>
> Interesting! There is the problem one can't represent "no 
> element of type T" and "one element of type T" with the same 
> type.
>

Objects can do it pretty well. They even segfault to when you 
forgot about it. in D that feature is integrated !