Scalar::List::Utils − A distribution of general−utility subroutines
use Scalar::Util
qw(blessed);
use List::Util qw(any);
"Scalar::List::Utils" does nothing on its own. It is packaged with several useful modules.
List::Util contains a selection of useful subroutines for operating on lists of values.
Scalar::Util contains a selection of useful subroutines for interrogating or manipulating scalar values.
Sub::Util contains a selection of useful subroutines for interrogating or manipulating subroutine references.