Stack
Perl 6 still has the stack functions from Perl 5, but now they also can be accessed by object notation:
my @stack; # just a array
@stack.push($elem); # add $elem to the end of @stack
$elem = @stack.pop; # get the last element back
@stack.elems == 0 # true, because the stack is empty
not @stack # also true because @stack is false