Make foreach element optional

[Steven Schveighoffer]

On 3/16/21 8:49 AM, Per Nordlöw wrote:
> I find myself writing
> 
> foreach (_; 0 .. n)
>      doSomething(); // no using the variable `_`
> 
> .
> 
> What about relaxing the syntax to allow
> 
>      foreach (; 0 .. n)
> 
> and/or
> 
>      foreach (0 .. n)
> 
> ?
> 
> Thereby making the `ForeachTypeList` of `AggregateForeach` in the 
> grammar rule [1] optional.
> 
> [1] https://dlang.org/spec/statement.html#foreach-statement

Meh, is this a common need though? The first form isn't terrible.

In general, I'd say it would be nice to designate _ as an unused 
variable (i.e. not allowed to access it, and it doesn't trigger 
shadowing errors). It's like this in Swift for instance.

-Steve