Feedback Thread: DIP 1037--Add Unary Operator ...--Community Review Round 1

[Paul Backus]

On Tuesday, 27 October 2020 at 10:54:46 UTC, Mike Parker wrote:
> This is the feedback thread for the first round of Community 
> Review of DIP 1037, "Add Unary Operator ...".

Given the map form, `expr ...`, it seems like it would be quite 
easy to implement the fold form, `expr BinOp ...`, using only 
library code. For example, the example in the DIP:

     (Tup == 10) || ...

Could also be written as

     any(only(Tup == 10 ...))

Or without Phobos:

     bool any(bool args[]...)
     {
         bool result = false;
         foreach (arg; args)
             result ||= arg;
         return result;
     }

     any(Tup == 10 ...)

The library versions require at worst O(1) template 
instantiations, and have the advantage that they are not limited 
to built-in operators. What are the advantages of `expr BinOp 
...` compared to this approach?