gistfile1.txt

#!perl6

role EnterValidator {}

role Blobject { }

class ObjectOne does Blobject {
}

class ObjectTwo does Blobject {
}

multi sub trait_mod:<is> ( Method $m, :$enter-validator! ) { 
    $m does EnterValidator;
} 

class Foo { 
    method any(Blobject $blob) returns Bool is enter-validator { say "any";} 
    method one(ObjectOne $blob) returns Bool is enter-validator { say "one"; }
    method two(ObjectTwo $blob) returns Bool is enter-validator { say "two"; }

    method run-em(Blobject $object) {
        for self.^methods.grep(EnterValidator) -> $meth {
            if $object.WHAT ~~ $meth.signature.params[1].type  {
                self.$meth($object);
            }
        }
    }
}

my $foo = Foo.new;

say "running one";

$foo.run-em(ObjectOne.new);

say "running two";

$foo.run-em(ObjectTwo.new);