or download this
eval{ $sv->FLAGS & SVf_POK && exists &{$curstash.'::'.$sv->PV} ;
warning "Bare sub name '" . $sv->PV . "' interpreted as string
+";
...
if( $sv->FLAGS & SVf_POK && exists &{$curstash.'::'.$sv->PV} ) {
warning "Bare sub name '" . $sv->PV . "' interpreted as string
+";
}