From type/Any

See Original text in context

multi method are(Any:D:)

Returns the strictest type (or role) to which all elements of the list will smartmatch. Returns Nil on an empty list.

say (1,2,3).are;        # OUTPUT: «(Int)␤» 
say <a b c>.are;        # OUTPUT: «(Str)␤» 
say <42 666>.are;       # OUTPUT: «(IntStr)␤» 
say (42,666e0).are;     # OUTPUT: «(Real)␤» 
say (42,i).are;         # OUTPUT: «(Numeric)␤» 
say ("a",42,3.14).are;  # OUTPUT: «(Cool)␤»

Available as of release 2022.02 of the Rakudo compiler.