Because SV's are C-structs consisting of 3 elements, first of which is a pointer to another struct ... see perlguts,Perl Guts Illustrated.

update: what jand said. variables in c are pass by value.

MJD says you can't just make shit up and expect the computer to know what you mean, retardo! I run a Win32 PPM repository for perl 5.6x+5.8x. I take requests. ** The Third rule of perl club is a statement of fact: pod is sexy.