?^ is a logical negation operator. Please note that this is not a bitwise negation. First, the argument is converted to a Boolean value, and then the result is negated.
my $x = 10; my $y = ?^$x; say $y; # False say $y.WHAT; # (Bool)
📘 Prefix operator ?^ in Raku
N. B. Perl 6 has been renamed to Raku. Click to read more.