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Perl::Critic::Policy::Moose::ProhibitMultipleWiths - Require role composition


version 1.05


Moose::Roles are, among other things, the answer to name conflicts plaguing multiple inheritance and mix-ins. However, to enjoy this protection, you must compose your roles together. Roles do not generate conflicts if they are consumed individually.

Pass all of your roles to a single with statement.

    # ok
    package Foo;

    use Moose::Role;

    with qw< Bar Baz >;

    # not ok
    package Foo;

    use Moose::Role;

    with 'Bar';
    with 'Baz';


This policy is part of Perl::Critic::Moose.


There is a single option, equivalent_modules. This allows you to specify modules that should be treated the same as Moose and Moose::Role, if, say, you were doing something with Moose::Exporter. For example, if you were to have this in your .perlcriticrc file:

    equivalent_modules = MyCompany::Moose MooseX::NewThing

then the following code would result in a violation:

    package Baz;

    use MyCompany::Moose;

    with 'Bing';
    with 'Bong';


Bugs may be submitted through the RT bug tracker (or

I am also usually active on IRC as 'drolsky' on irc://


  • Elliot Shank <>

  • Dave Rolsky <>


This software is copyright (c) 2008 - 2016 by Elliot Shank.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.