The worst Phobos template (in binderoo)

[Stefan Koch via Digitalmars-d]

On Thursday, 15 September 2016 at 22:58:12 UTC, Stefan Koch wrote:
> The Performance-Penalty will be less then on templates.
Let me add a disclaimer, I _think_ the performance penalty _can_ 
be less then the penalty on templates.

Also static if can sometimes lead to counter-intuitive situations,
static foreach will likely be worse in that regard.

Implementation issues aside, and the DIP aside.
What would be the semantics you would want for this ?