What does shift->{o} = $o; do in Perl? -

what line in subroutine mean?

shift->{o} = $o; 

i know shift usualy do, don't understand in context, dash , arrow.

inside sub/method,

shift 

is short for

shift(@_) 

a sub call places arguments in @_. method call same, precedes arguments invocant.

if in sub called sub, assigns $o element o of hash referenced first argument.

if in sub called method, assigns $o element o of hash referenced invocant. effectively, sets attribute o of object on method called.

in process, shift removes reference @_, though suspect might of no consequence.