What does func!thing mean?

[Jesse Phillips]

On Friday, 8 November 2013 at 20:15:14 UTC, ProgrammingGhost
wrote:
> Oh I see. Yes I understand C++ templates which is how I guessed 
> that. This FEELS UNUSUAL. Because it seems like it is 
> .map(!split.map(!(...))).reduce...

Simply put, anything more complex than a single name requires !()

      to!char[]("fish");

"test.d(5): Error: cannot resolve type for to!char"