# The Perl 6 Type System

    my Int  $int    = 1;
    my Bool $truth  = True;
    my Str  $string = "Gabriel Munoz";

    say $int.^mro;   # (Int) (Cool) (Any) (Mu)

    $int = $string;  # (runtime) Type check failed... expected 'Int'

See for a comprehensive list: http://doc.perl6.org/#Types