use 5.10.0;
use strict;
use warnings (FATAL => 'all');

my $a = "hello";
my $b = "hello";

print "a matches b\n" if($a ~~ $b);
print "a not matches b\n" if($a !~~ $b);
print "a matches not b\n" if($a ~~! $b);
print "a matches and a half b\n" if($a ~~~ $b);
print "a not matches and a half b\n" if($a !~~~ $b);
print "a double matches b\n" if($a ~~~~ $b);
print "a not double matches b\n" if($a !~~~~ $b);