Binary package “libscalar-does-perl” in ubuntu eoan

like ref() but useful

 Scalar::Does provides a "does()" built-in.
 .
 A check that "ref($thing) eq 'ARRAY'" doesn't allow you to accept an
 object that uses overloading to provide an array-like interface.
 .
 This package also includes IO::Detect, for detecting if a scalar is a
 filehandle (or something filehandle-like).