interesting semantic possible?

[JS]

BTW, I'm not saying D can't do anything like this

enum Dir { Left, Right, Both }

string strip(Dir dir = Dir.Both)(string s)

but one has to call it like

strip!(Dir.Left)(s); (or if using strings, strip!"Left"(s))

Possibly, to make it easier the compiler and localize the enum if 
one is used:

strip!Left(s); // compiler changes to strip!(Dir.Left)(s)