Documentation for postfix
.:<prefix> assembled from the following types:
An operator in prefix form can still be called like a method, that is, using the
. postfix notation, by preceding it by a colon. For example:
my = 1;say ++; # OUTPUT: «2␤»say .:<++>; # OUTPUT: «3␤»
Technically, not a real operator; it's syntax special-cased in the compiler.