The code above contains a bug - it returns an empty list when no arguments are given, but it should return a reference to an empty list. Fixing the bug also means the code can be shortened:

say"@$_"for(*_=sub{@_?map{my$x=$_;map{[$x,@$_]}_(@_[1..$#_])}@{$_[0]}:
+[]})->([1,2],["a","b"],["#","*","&"]);
[download]