# phpman > perldoc > Moose::Meta::TypeConstraint::DuckType

## NAME
    [Moose::Meta::TypeConstraint::DuckType](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AMeta%3A%3ATypeConstraint%3A%3ADuckType/markdown) - Type constraint for duck typing

## VERSION
    version 2.2200

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

## INHERITANCE
    "[Moose::Meta::TypeConstraint::DuckType](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AMeta%3A%3ATypeConstraint%3A%3ADuckType/markdown)" is a subclass of [Moose::Meta::TypeConstraint](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AMeta%3A%3ATypeConstraint/markdown).

## METHODS
  [Moose::Meta::TypeConstraint::DuckType](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AMeta%3A%3ATypeConstraint%3A%3ADuckType/markdown)->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](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AMeta%3A%3ATypeConstraint/markdown) object with the type as its parent.

    Note that it does *not* return a "[Moose::Meta::TypeConstraint::DuckType](https://www.chedong.com/phpMan.php/perldoc/Moose%3A%3AMeta%3A%3ATypeConstraint%3A%3ADuckType/markdown)" 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.