Tristate - wanna?

[Nordlöw via Digitalmars-d]

On Saturday, 26 October 2013 at 15:41:32 UTC, Andrei Alexandrescu 
wrote:
> While messing with std.allocator I explored the type below. I 
> ended up not using it, but was surprised that implementing it 
> was quite nontrivial. Should we add it to stdlib?

I can think of many variants of for this. What about

     { yes, // 1 chance
       no, // 0 chance
       likely, // > 1/2 chance
       unlikely, // < 1/2 chance
       unknown // any chance
     }

?

Partial implementation at

https://github.com/nordlow/justd/blob/master/fuzzy.d#L15

:)