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Moose::Meta::TypeConstraint::DuckType - Type constraint for duck typing


version 2.2207


This class represents type constraints based on an enumerated list of required methods.


Moose::Meta::TypeConstraint::DuckType is a subclass of Moose::Meta::TypeConstraint.



This creates a new duck type constraint based on the given %options.

It takes the same options as its parent, with several exceptions. First, it requires an additional option, methods. This should be an array reference containing a list of required method names. Second, it automatically sets the parent to the Object type.

Finally, it ignores any provided constraint option. The constraint is generated automatically based on the provided methods.


Returns the array reference of required methods provided to the constructor.


This returns a new Moose::Meta::TypeConstraint object with the type as its parent.

Note that it does not return a Moose::Meta::TypeConstraint::DuckType object!


See "BUGS" in Moose for details on reporting bugs.


  • Stevan Little <>

  • Dave Rolsky <>

  • Jesse Luehrs <>

  • Shawn M Moore <>

  • יובל קוג'מן (Yuval Kogman) <>

  • Karen Etheridge <>

  • Florian Ragwitz <>

  • Hans Dieter Pearcey <>

  • Chris Prather <>

  • Matt S Trout <>


This software is copyright (c) 2006 by Infinity Interactive, Inc.

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