Project Elvis

[Neia Neutuladh]

On Saturday, 28 October 2017 at 11:38:52 UTC, Andrei Alexandrescu 
wrote:
> Walter and I decided to kick-off project Elvis for adding the 
> homonym operator to D.

It's easy to write in function form:

   auto orElse(T)(T a, lazy T b)
   {
     return a ? a : b;
   }

   writeln(args[1].length.orElse(fibonacci(50)));

This version can also be specialized for things like Nullable, 
where you can't necessarily cast it safely to a boolean but have 
a check for validity.

Is it that valuable to have an operator for it instead?


As an aside, I believe feepingcreature had a custom infix 
operator for this sort of thing defined, so you could write:

   (a /or/ b /or/ c).doStuff();

The implementation (along with /and/) is left as an exercise to 
the reader.