Copy On Write in perl 5.10

Copy On Write in perl 5.10

By Nicholas Clark from London.pm
Lightning talk
Language:

Currently in perl when you write $a = $b, the contents of $b are
immediately copied into $a. In theory perl could just pretend that it did
the copy, and only actually do it if one of $a or $b is modified. If $b
is a large string, and $a is never modified this could potentially be a big
efficiency gain. This talk consists of simple pictures - how I didn't do it,
and how I did.