---
name: "Mouse::Role"
section: "3pm"
platform: "linux"
package: "perl-mouse"
version: "2.6.2-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Mouse::Role"
---

# Mouse::Role(3pm)

The Mouse Role

## NAME

Mouse::Role - The Mouse Role

## VERSION

This document describes Mouse version v2.6.2

## SYNOPSIS

```
    package Comparable;
    use Mouse::Role; # the package is now a Mouse role
    # Declare methods that are required by this role
    requires qw(compare);
    # Define methods this role provides
    sub equals {
        my($self, $other) = @_;
        return $self->compare($other) == 0;
    }
    # and later
    package MyObject;
    use Mouse;
    with qw(Comparable); # Now MyObject can equals()
    sub compare {
        # ...
    }
    my $foo = MyObject->new();
    my $bar = MyObject->new();
    $obj->equals($bar); # yes, it is comparable
```

## DESCRIPTION

This module declares the caller class to be a Mouse role.

The concept of roles is documented in Moose::Manual::Roles. This document serves as API documentation.

## EXPORTED FUNCTIONS

Mouse::Role supports all of the functions that Mouse exports, but differs slightly in how some items are handled (see "CAVEATS" below for details).

Mouse::Role also offers two role-specific keywords:

### requires(@method\_names)

Roles can require that certain methods are implemented by any class which `"does"` the role.

Note that attribute accessors also count as methods for the purposes of satisfying the requirements of a role.

### excludes(@role\_names)

This is exported but not implemented in Mouse.

## IMPORT AND UNIMPORT

### import

Importing Mouse::Role will give you sugar. `"-traits"` are also supported.

### unimport

Please unimport (`"no Mouse::Role"`) so that if someone calls one of the keywords (such as "has") it will break loudly instead breaking subtly.

## CAVEATS

Role support has only a few caveats:

- •

  Roles cannot use the `"extends"` keyword; it will throw an exception for now. The same is true of the `"augment"` and `"inner"` keywords (not sure those really make sense for roles). All other Mouse keywords will be *deferred* so that they can be applied to the consuming class.

- •

  Role composition does its best to **not** be order-sensitive when it comes to conflict resolution and requirements detection. However, it is order-sensitive when it comes to method modifiers. All before/around/after modifiers are included whenever a role is composed into a class, and then applied in the order in which the roles are used. This also means that there is no conflict for before/around/after modifiers.

  In most cases, this will be a non-issue; however, it is something to keep in mind when using method modifiers in a role. You should never assume any ordering.

## SEE ALSO

Mouse

Moose::Role

Moose::Manual::Roles

Moose::Spec::Role