---
name: "Moose::Meta::TypeConstraint::DuckType"
section: "3pm"
platform: "linux"
package: "perl-moose"
version: "2.4001-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Moose::Meta::TypeConstraint::DuckType"
---

# Moose::Meta::TypeConstraint::DuckType(3pm)

Type constraint for duck typing

## NAME

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

## VERSION

version 2.4001

## DESCRIPTION

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

## INHERITANCE

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

## METHODS

### Moose::Meta::TypeConstraint::DuckType-\>new(%options)

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"`.

### $constraint-\>methods

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

### $constraint-\>create\_child\_type

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!

## BUGS

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

## AUTHORS

- •

  Stevan Little \<stevan@cpan.org\>

- •

  Dave Rolsky \<autarch@urth.org\>

- •

  Jesse Luehrs \<doy@cpan.org\>

- •

  Shawn M Moore \<sartak@cpan.org\>

- •

  יובל קוג'מן (Yuval Kogman) \<nothingmuch@woobling.org\>

- •

  Karen Etheridge \<ether@cpan.org\>

- •

  Florian Ragwitz \<rafl@debian.org\>

- •

  Hans Dieter Pearcey \<hdp@cpan.org\>

- •

  Chris Prather \<chris@prather.org\>

- •

  Matt S Trout \<mstrout@cpan.org\>

## COPYRIGHT AND LICENSE

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.