In Perl 6 you can do that with the $object.?method syntax, and that works in Rakudo today:

$ cat test.t
class A {
    method some-method {
        say "called some-method";
    }
}
my $a = undef;
my $b = A.new;
for $a, $b -> $obj {
    $obj.?some-method
}

$ ./perl6 test.t
called some-method
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You can also use it to call a method on $_ like this:

for $a, $b {
    .?some-method
}
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