Option!T

[Jesse Phillips]

On Tuesday, 10 December 2013 at 17:28:26 UTC, Andrei Alexandrescu 
wrote:
> I talked to a programmer who knows Scala (among others) and he 
> mentioned the usefulness of the Option type - a zero or one 
> element collection (range in D terminology). Here's an article 
> discussing it: 
> http://danielwestheide.com/blog/2012/12/19/the-neophytes-guide-to-scala-part-5-the-option-type.html
>
> 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". Should we follow Scala's 
> example and add it?
>
>
> Andrei

Having a easy way to return a single element range which may be 
empty is probably a good idea. It could make a good change to 
style, but I don't use Option in other languages. For that reason 
I'm not sure Option range probably doesn't have the same 
semantics as expected by users of other languages.