Project Elvis

[Andrei Alexandrescu]

On 11/05/2017 07:20 PM, Neia Neutuladh wrote:
> 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.

If a DIP emerges, it would need to present such alternatives and argue 
how it adds value over them. -- Andrei