TYPEMAP
pe_watcher * O_WATCHER
pe_event * O_EVENT
pe_genericsrc * O_GENERICSRC
INPUT
O_WATCHER
$var = ($type) sv_2watcher($arg)
O_EVENT
$var = ($type) sv_2event($arg)
O_GENERICSRC
$var = ($type) sv_2genericsrc($arg)
OUTPUT
O_WATCHER
croak("use watcher_2sv($var)")
O_EVENT
croak("use event_2sv($var)")
O_GENERICSRC
croak("use genericsrc_2sv($var)")