In Moose, how can I tell whether one object's class is a subclass of another object's class?

Suppose I have two objects $obj1 and $obj2 that are both instances of Moose classes. I want to find out which of the following applies:

$obj1's class is the same as $obj2's;
$obj1's class is a subclass of $obj2's;
$obj1's class is a superclass of $obj2's;
Neither object's class is a subclass of the other's.

How can I do this?

Solution

Is $obj1's class the same as $obj2's?
```
ref $obj1 eq ref $obj2;
```
Is $obj1's class a subclass of $obj2's?
```
$obj1->isa(ref $obj2);
```
Is $obj1's class a superclass of $obj2's?
```
$obj2->isa(ref $obj1);
```
Neither object's class is a subclass of the other's.

See above.

Update:

In response to comments regarding roles applied at run time:

package My::X;

use Moose; use namespace::autoclean;

sub boo { }

__PACKAGE__->meta->make_immutable;

package My::Y;

use Moose; use namespace::autoclean;

extends 'My::X';

__PACKAGE__->meta->make_immutable;

package My::Z;

use Moose::Role; use namespace::autoclean;

requires 'boo';

package main;

use Test::More tests => 2;

use Moose::Util qw( apply_all_roles );

my $x = My::X->new;
my $y = My::Y->new;

ok($y->isa(ref $x), 'Before role was applied at runtime');

apply_all_roles($x, 'My::Z');

ok($y->isa(ref $x), 'After role was applied at runtime');

Output:

1..2
ok 1 - Before role was applied at runtime
not ok 2 - After role was applied at runtime
#   Failed test 'After role was applied at runtime' at C:\Temp\t.pl line 36.
# Looks like you failed 1 test of 2.