DIP 57: static foreach

[Timon Gehr]

On 03/10/2014 07:40 AM, Kenji Hara wrote:
> 2014-03-10 6:31 GMT+09:00 Timon Gehr <timon.gehr at gmx.ch
> <mailto:timon.gehr at gmx.ch>>:
>
>     http://wiki.dlang.org/DIP57 <http://wiki.dlang.org/DIP57/>
>
>     Thoughts?
>
>
>  From the "Semantics" section:
>
>  > For static foreach statements, break and continue are supported and
> treated like for foreach statements over tuples.
>
> This is questionable sentence. On the foreach with tuple iteration,
> break and continue have no effect for the unrolling.
> ...

That's what is meant, and indeed this is visible in the examples section.

> void main()
> {
>      import std.typetuple, std.stdio;
>
>      foreach (i; TypeTuple!(1, 2, 3))
>      {
>          static if (i == 2) continue;
>          else static if (i == 3) break;
>
>          pragma(msg, "CT: i = ", i); // prints 1, 2, and 3 in CT
>          writeln("RT: i = ", i);     // prints only 1 in RT
>      }
> }
>
> So, I think that static foreach *cannot* support break and continue as
> same as foreach with tuples.
>
> Kenji Hara
>

Yes it can. What is your suggestion? Influencing the unrolling?