Страницы справочника OS X

Эта страница руководства для  версии 10.9 Mac OS X

Читать страницы руководства

Moose::Manual::Delta(3)              User Contributed Perl Documentation             Moose::Manual::Delta(3)



NAME
       Moose::Manual::Delta - Important Changes in Moose

VERSION
       version 2.0205

DESCRIPTION
       This documents any important or noteworthy changes in Moose, with a focus on things that affect
       backwards compatibility. This does duplicate data from the Changes file, but aims to provide more
       details and when possible workarounds.

       Besides helping keep up with changes, you can also use this document for finding the lowest version
       of Moose that supported a given feature.  If you encounter a problem and have a solution but don't
       see it documented here, or think we missed an important feature, please send us a patch.

2.0205
       Array and Hash native traits provide a "shallow_clone" method
           The Array and Hash native traits now provide a "shallow_clone" method, which will return a
           reference to a new container with the same contents as the attribute's reference.

2.0100
       Hand-optimized type constraint code is deprecated in favor of inlining
           Moose allows you to provide a hand-optimized version of a type constraint's subroutine reference.
           This version allows type constraints to generate inline code, and you should use this inlining
           instead of providing a hand-optimized subroutine reference.

           This affects the "optimize_as" sub exported by Moose::Util::TypeConstraints. Use "inline_as"
           instead.

           This will start warning in the 2.0300 release.

2.0002
       More useful type constraint error messages
           If you have Devel::PartialDump version 0.14 or higher installed, Moose's type constraint error
           messages will use it to display the invalid value, rather than just displaying it directly. This
           will generally be much more useful. For instance, instead of this:

             Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value ARRAY(0x275eed8)

           the error message will instead look like

             Attribute (foo) does not pass the type constraint because: Validation failed for 'ArrayRef[Int]' with value [ "a" ]

           Note that Devel::PartialDump can't be made a direct dependency at the moment, because it uses
           Moose itself, but we're considering options to make this easier.

2.0000
       Roles have their own default attribute metaclass
           Previously, when a role was applied to a class, it would use the attribute metaclass defined in
           the class when copying over the attributes in the role.  This was wrong, because for instance,
           using MooseX::FollowPBP in the class would end up renaming all of the accessors generated by the
           role, some of which may be being called in the role, causing it to break. Roles now keep track of
           their own attribute metaclass to use by default when being applied to a class (defaulting to
           Moose::Meta::Attribute). This is modifiable using Moose::Util::MetaRole by passing the
           "applied_attribute" key to the "role_metaroles" option, as in:

               Moose::Util::MetaRole::apply_metaroles(
                   for => __PACKAGE__,
                   class_metaroles => {
                       attribute => ['My::Meta::Role::Attribute'],
                   },
                   role_metaroles => {
                       applied_attribute => ['My::Meta::Role::Attribute'],
                   },
               );

       Class::MOP has been folded into the Moose dist
           Moose and Class::MOP are tightly related enough that they have always had to be kept pretty
           closely in step in terms of versions. Making them into a single dist should simplify the upgrade
           process for users, as it should no longer be possible to upgrade one without the other and
           potentially cause issues. No functionality has changed, and this should be entirely transparent.

       Moose's conflict checking is more robust and useful
           There are two parts to this. The most useful one right now is that Moose will ship with a
           "moose-outdated" script, which can be run at any point to list the modules which are installed
           that conflict with the installed version of Moose.  After upgrading Moose, running
           "moose-outdated | cpanm" should be sufficient to ensure that all of the Moose extensions you use
           will continue to work.

           The other part is that Moose's "META.json" file will also specify the conflicts under the
           "x_conflicts" key. We are working with the Perl tool chain developers to try to get conflicts
           support added to CPAN clients, and if/when that happens, the metadata already exists, and so the
           conflict checking will become automatic.

       Most deprecated APIs/features are slated for removal in Moose 2.0200
           Most of the deprecated APIs and features in Moose will start throwing an error in Moose 2.0200.
           Some of the features will go away entirely, and some will simply throw an error.

           The things on the chopping block are:

           •       Old public methods in Class::MOP and Moose

                   This includes things like "Class::MOP::Class->get_attribute_map",
                   "Class::MOP::Class->construct_instance", and many others. These were deprecated in
                   Class::MOP 0.80_01, released on April 5, 2009.

                   These methods will be removed entirely in Moose 2.0200.

           •       Old public functions in Class::MOP

                   This include "Class::MOP::subname", "Class::MOP::in_global_destruction", and the
                   "Class::MOP::HAS_ISAREV" constant. The first two were deprecated in 0.84, and the last in
                   0.80. Class::MOP 0.84 was released on May 12, 2009.

                   These functions will be removed entirely in Moose 2.0200.

           •       The "alias" and "excludes" option for role composition

                   These were renamed to "-alias" and "-excludes" in Moose 0.89, released on August 13,
                   2009.

                   Passing these will throw an error in Moose 2.0200.

           •       The old Moose::Util::MetaRole API

                   This include the "apply_metaclass_roles()" function, as well as passing the "for_class"
                   or any key ending in "_roles" to "apply_metaroles()". This was deprecated in Moose
                   0.93_01, released on January 4, 2010.

                   These will all throw an error in Moose 2.0200.

           •       Passing plain lists to "type()" or "subtype()"

                   The old API for these functions allowed you to pass a plain list of parameter, rather
                   than a list of hash references (which is what "as()", "where", etc. return). This was
                   deprecated in Moose 0.71_01, released on February 22, 2009.

                   This will throw an error in Moose 2.0200.

           •       The Role subtype

                   This subtype was deprecated in Moose 0.84, released on June 26, 2009.

                   This will be removed entirely in Moose 2.0200.

1.21
       •   New release policy

           As of the 2.0 release, Moose now has an official release and support policy, documented in
           Moose::Manual::Support. All API changes will now go through a deprecation cycle of at least one
           year, after which the deprecated API can be removed. Deprecations and removals will only happen
           in major releases.

           In between major releases, we will still make minor releases to add new features, fix bugs,
           update documentation, etc.

1.16
       Configurable stacktraces
           Classes which use the Moose::Error::Default error class can now have stacktraces disabled by
           setting the "MOOSE_ERROR_STYLE" env var to "croak".  This is experimental, fairly incomplete, and
           won't work in all cases (because Moose's error system in general is all of these things), but
           this should allow for reducing at least some of the verbosity in most cases.

1.15
       Native Delegations
           In previous versions of Moose, the Native delegations were created as closures. The generated
           code was often quite slow compared to doing the same thing by hand. For example, the Array's push
           delegation ended up doing something like this:

             push @{ $self->$reader() }, @_;

           If the attribute was created without a reader, the $reader sub reference followed a very slow
           code path. Even with a reader, this is still slower than it needs to be.

           Native delegations are now generated as inline code, just like other accessors, so we can access
           the slot directly.

           In addition, native traits now do proper constraint checking in all cases. In particular,
           constraint checking has been improved for array and hash references. Previously, only the
           contained type (the "Str" in "HashRef[Str]") would be checked when a new value was added to the
           collection. However, if there was a constraint that applied to the whole value, this was never
           checked.

           In addition, coercions are now called on the whole value.

           The delegation methods now do more argument checking. All of the methods check that a valid
           number of arguments were passed to the method. In addition, the delegation methods check that the
           arguments are sane (array indexes, hash keys, numbers, etc.) when applicable. We have tried to
           emulate the behavior of Perl builtins as much as possible.

           Finally, triggers are called whenever the value of the attribute is changed by a Native
           delegation.

           These changes are only likely to break code in a few cases.

           The inlining code may or may not preserve the original reference when changes are made. In some
           cases, methods which change the value may replace it entirely. This will break tied values.

           If you have a typed arrayref or hashref attribute where the type enforces a constraint on the
           whole collection, this constraint will now be checked. It's possible that code which previously
           ran without errors will now cause the constraint to fail. However, presumably this is a good
           thing ;)

           If you are passing invalid arguments to a delegation which were previously being ignored, these
           calls will now fail.

           If your code relied on the trigger only being called for a regular writer, that may cause
           problems.

           As always, you are encouraged to test before deploying the latest version of Moose to production.

       Defaults is and default for String, Counter, and Bool
           A few native traits (String, Counter, Bool) provide default values of "is" and "default" when you
           created an attribute. Allowing them to provide these values is now deprecated. Supply the value
           yourself when creating the attribute.

       The "meta" method
           Moose and Class::MOP have been cleaned up internally enough to make the "meta" method that you
           get by default optional. "use Moose" and "use Moose::Role" now can take an additional
           "-meta_name" option, which tells Moose what name to use when installing the "meta" method.
           Passing "undef" to this option suppresses generation of the "meta" method entirely. This should
           be useful for users of modules which also use a "meta" method or function, such as Curses or
           Rose::DB::Object.

1.09
       All deprecated features now warn
           Previously, deprecation mostly consisted of simply saying "X is deprecated" in the Changes file.
           We were not very consistent about actually warning. Now, all deprecated features still present in
           Moose actually give a warning. The warning is issued once per calling package. See
           Moose::Deprecated for more details.

       You cannot pass "coerce => 1" unless the attribute's type constraint has a coercion
           Previously, this was accepted, and it sort of worked, except that if you attempted to set the
           attribute after the object was created, you would get a runtime error.

           Now you will get a warning when you attempt to define the attribute.

       "no Moose", "no Moose::Role", and "no Moose::Exporter" no longer unimport strict and warnings
           This change was made in 1.05, and has now been reverted. We don't know if the user has explicitly
           loaded strict or warnings on their own, and unimporting them is just broken in that case.

       Reversed logic when defining which options can be changed
           Moose::Meta::Attribute now allows all options to be changed in an overridden attribute. The
           previous behaviour required each option to be whitelisted using the
           "legal_options_for_inheritance" method. This method has been removed, and there is a new method,
           "illegal_options_for_inheritance", which can now be used to prevent certain options from being
           changeable.

           In addition, we only throw an error if the illegal option is actually changed. If the superclass
           didn't specify this option at all when defining the attribute, the subclass version can still add
           it as an option.

           Example of overriding this in an attribute trait:

             package Bar::Meta::Attribute;
             use Moose::Role;

             has 'my_illegal_option' => (
                 isa => 'CodeRef',
                 is  => 'rw',
             );

             around illegal_options_for_inheritance => sub {
                 return ( shift->(@_), qw/my_illegal_option/ );
             };

1.05
       "BUILD" in Moose::Object methods are now called when calling "new_object"
           Previously, "BUILD" methods would only be called from "Moose::Object::new", but now they are also
           called when constructing an object via "Moose::Meta::Class::new_object". "BUILD" methods are an
           inherent part of the object construction process, and this should make "$meta->new_object"
           actually usable without forcing people to use "$meta->name->new".

       "no Moose", "no Moose::Role", and "no Moose::Exporter" now unimport strict and warnings
           In the interest of having "no Moose" clean up everything that "use Moose" does in the calling
           scope, "no Moose" (as well as all other Moose::Exporter-using modules) now unimports strict and
           warnings.

       Metaclass compatibility checking and fixing should be much more robust
           The metaclass compatibility checking and fixing algorithms have been completely rewritten, in
           both Class::MOP and Moose. This should resolve many confusing errors when dealing with non-Moose
           inheritance and with custom metaclasses for things like attributes, constructors, etc. For
           correct code, the only thing that should require a change is that custom error metaclasses must
           now inherit from Moose::Error::Default.

1.02
       Moose::Meta::TypeConstraint::Class is_subtype_of behavior
           Earlier versions of is_subtype_of would incorrectly return true when called with itself, its own
           TC name or its class name as an argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This behavior
           was a caused by "isa" being checked before the class name. The old behavior can be accessed with
           is_type_of

1.00
       Moose::Meta::Attribute::Native::Trait::Code no longer creates reader methods by default
           Earlier versions of Moose::Meta::Attribute::Native::Trait::Code created read-only accessors for
           the attributes it's been applied to, even if you didn't ask for it with "is => 'ro'". This
           incorrect behaviour has now been fixed.

0.95
       Moose::Util add_method_modifier behavior
           add_method_modifier (and subsequently the sugar functions Moose::before, Moose::after, and
           Moose::around) can now accept arrayrefs, with the same behavior as lists. Types other than
           arrayref and regexp result in an error.

0.93_01 and 0.94
       Moose::Util::MetaRole API has changed
           The "apply_metaclass_roles" function is now called "apply_metaroles". The way arguments are
           supplied has been changed to force you to distinguish between metaroles applied to
           Moose::Meta::Class (and helpers) versus Moose::Meta::Role.

           The old API still works, but will warn in a future release, and eventually be removed.

       Moose::Meta::Role has real attributes
           The attributes returned by Moose::Meta::Role are now instances of the
           Moose::Meta::Role::Attribute class, instead of bare hash references.

       "no Moose" now removes "blessed" and "confess"
           Moose is now smart enough to know exactly what it exported, even when it re-exports functions
           from other packages. When you unimport Moose, it will remove these functions from your namespace
           unless you also imported them directly from their respective packages.

           If you have a "no Moose" in your code before you call "blessed" or "confess", your code will
           break. You can either move the "no Moose" call later in your code, or explicitly import the
           relevant functions from the packages that provide them.

       Moose::Exporter is smarter about unimporting re-exports
           The change above comes from a general improvement to Moose::Exporter. It will now unimport any
           function it exports, even if that function is a re-export from another package.

       Attributes in roles can no longer override class attributes with "+foo"
           Previously, this worked more or less accidentally, because role attributes weren't objects. This
           was never documented, but a few MooseX modules took advantage of this.

       The composition_class_roles attribute in Moose::Meta::Role is now a method
           This was done to make it possible for roles to alter the the list of composition class roles by
           applying a method modifiers. Previously, this was an attribute and MooseX modules override it.
           Since that no longer works, this was made a method.

           This should be an attribute, so this may switch back to being an attribute in the future if we
           can figure out how to make this work.

0.93
       Calling $object->new() is no longer deprecated
           We decided to undeprecate this. Now it just works.

       Both "get_method_map" and "get_attribute_map" is deprecated
           These metaclass methods were never meant to be public, and they are both now deprecated. The work
           around if you still need the functionality they provided is to iterate over the list of names
           manually.

               my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;

           This was actually a change in Class::MOP, but this version of Moose requires a version of
           Class::MOP that includes said change.

0.90
       Added Native delegation for Code refs
           See Moose::Meta::Attribute::Native::Trait::Code for details.

       Calling $object->new() is deprecated
           Moose has long supported this, but it's never really been documented, and we don't think this is
           a good practice. If you want to construct an object from an existing object, you should provide
           some sort of alternate constructor like "$object->clone".

           Calling "$object->new" now issues a warning, and will be an error in a future release.

       Moose no longer warns if you call "make_immutable" for a class with mutable ancestors
           While in theory this is a good thing to warn about, we found so many exceptions to this that
           doing this properly became quite problematic.

0.89_02
       New Native delegation methods from List::Util and List::MoreUtils
           In particular, we now have "reduce", "shuffle", "uniq", and "natatime".

       The Moose::Exporter with_caller feature is now deprecated
           Use "with_meta" instead. The "with_caller" option will start warning in a future release.

       Moose now warns if you call "make_immutable" for a class with mutable ancestors
           This is dangerous because modifying a class after a subclass has been immutabilized will lead to
           incorrect results in the subclass, due to inlining, caching, etc. This occasionally happens
           accidentally, when a class loads one of its subclasses in the middle of its class definition, so
           pointing out that this may cause issues should be helpful. Metaclasses (classes that inherit from
           Class::MOP::Object) are currently exempt from this check, since at the moment we aren't very
           consistent about which metaclasses we immutabilize.

       "enum" and "duck_type" now take arrayrefs for all forms
           Previously, calling these functions with a list would take the first element of the list as the
           type constraint name, and use the remainder as the enum values or method names. This makes the
           interface inconsistent with the anon-type forms of these functions (which must take an arrayref),
           and a free-form list where the first value is sometimes special is hard to validate (and harder
           to give reasonable error messages for). These functions have been changed to take arrayrefs in
           all their forms - so, "enum 'My::Type' => [qw(foo bar)]" is now the preferred way to create an
           enum type constraint. The old syntax still works for now, but it will hopefully be deprecated and
           removed in a future release.

0.89_01
       Moose::Meta::Attribute::Native has been moved into the Moose core from MooseX::AttributeHelpers.
       Major changes include:

       "traits", not "metaclass"
           Method providers are only available via traits.

       "handles", not "provides" or "curries"
           The "provides" syntax was like core Moose "handles => HASHREF" syntax, but with the keys and
           values reversed.  This was confusing, and AttributeHelpers now uses "handles => HASHREF" in a way
           that should be intuitive to anyone already familiar with how it is used for other attributes.

           The "curries" functionality provided by AttributeHelpers has been generalized to apply to all
           cases of "handles => HASHREF", though not every piece of functionality has been ported (currying
           with a CODEREF is not supported).

       "empty" is now "is_empty", and means empty, not non-empty
           Previously, the "empty" method provided by Arrays and Hashes returned true if the attribute was
           not empty (no elements).  Now it returns true if the attribute is empty. It was also renamed to
           "is_empty", to reflect this.

       "find" was renamed to "first", and "first" and "last" were removed
           List::Util refers to the functionality that we used to provide under "find" as first, so that
           will likely be more familiar (and will fit in better if we decide to add more List::Util
           functions). "first" and "last" were removed, since their functionality is easily duplicated with
           curries of "get".

       Helpers that take a coderef of one argument now use $_
           Subroutines passed as the first argument to "first", "map", and "grep" now receive their argument
           in $_ rather than as a parameter to the subroutine.  Helpers that take a coderef of two or more
           arguments remain using the argument list (there are technical limitations to using $a and $b like
           "sort" does).

           See Moose::Meta::Attribute::Native for the new documentation.

       The "alias" and "excludes" role parameters have been renamed to "-alias" and "-excludes". The old
       names still work, but new code should use the new names, and eventually the old ones will be
       deprecated and removed.

0.89
       "use Moose -metaclass => 'Foo'" now does alias resolution, just like "-traits" (and the "metaclass"
       and "traits" options to "has").

       Added two functions "meta_class_alias" and "meta_attribute_alias" to Moose::Util, to simplify
       aliasing metaclasses and metatraits. This is a wrapper around the old

         package Moose::Meta::Class::Custom::Trait::FooTrait;
         sub register_implementation { 'My::Meta::Trait' }

       way of doing this.

0.84
       When an attribute generates no accessors, we now warn. This is to help users who forget the "is"
       option. If you really do not want any accessors, you can use "is => 'bare'". You can maintain back
       compat with older versions of Moose by using something like:

           ($Moose::VERSION >= 0.84 ? is => 'bare' : ())

       When an accessor overwrites an existing method, we now warn. To work around this warning (if you
       really must have this behavior), you can explicitly remove the method before creating it as an
       accessor:

           sub foo {}

           __PACKAGE__->meta->remove_method('foo');

           has foo => (
               is => 'ro',
           );

       When an unknown option is passed to "has", we now warn. You can silence the warning by fixing your
       code. :)

       The "Role" type has been deprecated. On its own, it was useless, since it just checked
       "$object->can('does')". If you were using it as a parent type, just call "role_type('Role::Name')" to
       create an appropriate type instead.

0.78
       "use Moose::Exporter;" now imports "strict" and "warnings" into packages that use it.

0.77
       "DEMOLISHALL" and "DEMOLISH" now receive an argument indicating whether or not we are in global
       destruction.

0.76
       Type constraints no longer run coercions for a value that already matches the constraint.  This may
       affect some (arguably buggy) edge case coercions that rely on side effects in the "via" clause.

0.75
       Moose::Exporter now accepts the "-metaclass" option for easily overriding the metaclass (without
       metaclass). This works for classes and roles.

0.74
       Added a "duck_type" sugar function to Moose::Util::TypeConstraints to make integration with non-Moose
       classes easier. It simply checks if "$obj->can()" a list of methods.

       A number of methods (mostly inherited from Class::MOP) have been renamed with a leading underscore to
       indicate their internal-ness. The old method names will still work for a while, but will warn that
       the method has been renamed. In a few cases, the method will be removed entirely in the future. This
       may affect MooseX authors who were using these methods.

0.73
       Calling "subtype" with a name as the only argument now throws an exception. If you want an anonymous
       subtype do:

           my $subtype = subtype as 'Foo';

       This is related to the changes in version 0.71_01.

       The "is_needed" method in Moose::Meta::Method::Destructor is now only usable as a class method.
       Previously, it worked as a class or object method, with a different internal implementation for each
       version.

       The internals of making a class immutable changed a lot in Class::MOP 0.78_02, and Moose's internals
       have changed along with it. The external "$metaclass->make_immutable" method still works the same
       way.

0.72
       A mutable class accepted "Foo->new(undef)" without complaint, while an immutable class would blow up
       with an unhelpful error. Now, in both cases we throw a helpful error instead.

       This "feature" was originally added to allow for cases such as this:

         my $args;

         if ( something() ) {
             $args = {...};
         }

         return My::Class->new($args);

       But we decided this is a bad idea and a little too magical, because it can easily mask real errors.

0.71_01
       Calling "type" or "subtype" without the sugar helpers ("as", "where", "message") is now deprecated.

       As a side effect, this meant we ended up using Perl prototypes on "as", and code like this will no
       longer work:

         use Moose::Util::TypeConstraints;
         use Declare::Constraints::Simple -All;

         subtype 'ArrayOfInts'
             => as 'ArrayRef'
             => IsArrayRef(IsInt);

       Instead it must be changed to this:

         subtype(
             'ArrayOfInts' => {
                 as    => 'ArrayRef',
                 where => IsArrayRef(IsInt)
             }
         );

       If you want to maintain backwards compat with older versions of Moose, you must explicitly test
       Moose's "VERSION":

         if ( Moose->VERSION < 0.71_01 ) {
             subtype 'ArrayOfInts'
                 => as 'ArrayRef'
                 => IsArrayRef(IsInt);
         }
         else {
             subtype(
                 'ArrayOfInts' => {
                     as    => 'ArrayRef',
                     where => IsArrayRef(IsInt)
                 }
             );
         }

0.70
       We no longer pass the meta-attribute object as a final argument to triggers. This actually changed
       for inlined code a while back, but the non-inlined version and the docs were still out of date.

       If by some chance you actually used this feature, the workaround is simple. You fetch the attribute
       object from out of the $self that is passed as the first argument to trigger, like so:

         has 'foo' => (
             is      => 'ro',
             isa     => 'Any',
             trigger => sub {
                 my ( $self, $value ) = @_;
                 my $attr = $self->meta->find_attribute_by_name('foo');

                 # ...
             }
         );

0.66
       If you created a subtype and passed a parent that Moose didn't know about, it simply ignored the
       parent. Now it automatically creates the parent as a class type. This may not be what you want, but
       is less broken than before.

       You could declare a name with subtype such as "Foo!Bar". Moose would accept this allowed, but if you
       used it in a parameterized type such as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting
       on names created via the sugar functions, so that they can only contain alphanumerics, ":", and ".".

0.65
       Methods created via an attribute can now fulfill a "requires" declaration for a role. Honestly we
       don't know why Stevan didn't make this work originally, he was just insane or something.

       Stack traces from inlined code will now report the line and file as being in your class, as opposed
       to in Moose guts.

0.62_02
       When a class does not provide all of a role's required methods, the error thrown now mentions all of
       the missing methods, as opposed to just the first missing method.

       Moose will no longer inline a constructor for your class unless it inherits its constructor from
       Moose::Object, and will warn when it doesn't inline. If you want to force inlining anyway, pass
       "replace_constructor => 1" to "make_immutable".

       If you want to get rid of the warning, pass "inline_constructor => 0".

0.62
       Removed the (deprecated) "make_immutable" keyword.

       Removing an attribute from a class now also removes delegation ("handles") methods installed for that
       attribute. This is correct behavior, but if you were wrongly relying on it you might get bit.

0.58
       Roles now add methods by calling "add_method", not "alias_method". They make sure to always provide a
       method object, which will be cloned internally. This means that it is now possible to track the
       source of a method provided by a role, and even follow its history through intermediate roles.  This
       means that methods added by a role now show up when looking at a class's method list/map.

       Parameter and Union args are now sorted, this makes Int|Str the same constraint as Str|Int. Also,
       incoming type constraint strings are normalized to remove all whitespace differences. This is mostly
       for internals and should not affect outside code.

       Moose::Exporter will no longer remove a subroutine that the exporting package re-exports. Moose re-exports reexports
       exports the Carp::confess function, among others. The reasoning is that we cannot know whether you
       have also explicitly imported those functions for your own use, so we err on the safe side and always
       keep them.

0.56
       "Moose::init_meta" should now be called as a method.

       New modules for extension writers, Moose::Exporter and Moose::Util::MetaRole.

0.55_01
       Implemented metaclass traits (and wrote a recipe for it):

         use Moose -traits => 'Foo'

       This should make writing small Moose extensions a little easier.

0.55
       Fixed "coerce" to accept anon types just like "subtype" can.  So that you can do:

         coerce $some_anon_type => from 'Str' => via { ... };

0.51
       Added "BUILDARGS", a new step in "Moose::Object->new()".

0.49
       Fixed how the "is => (ro|rw)" works with custom defined "reader", "writer" and "accessor" options.
       See the below table for details:

         is => ro, writer => _foo    # turns into (reader => foo, writer => _foo)
         is => rw, writer => _foo    # turns into (reader => foo, writer => _foo)
         is => rw, accessor => _foo  # turns into (accessor => _foo)
         is => ro, accessor => _foo  # error, accesor is rw

0.45
       The "before/around/after" method modifiers now support regexp matching of method names. NOTE: this
       only works for classes, it is currently not supported in roles, but, ... patches welcome.

       The "has" keyword for roles now accepts the same array ref form that Moose.pm does for classes.

       A trigger on a read-only attribute is no longer an error, as it's useful to trigger off of the
       constructor.

       Subtypes of parameterizable types now are parameterizable types themselves.

0.44
       Fixed issue where "DEMOLISHALL" was eating the value in $@, and so not working correctly. It still
       kind of eats them, but so does vanilla perl.

0.41
       Inherited attributes may now be extended without restriction on the type ('isa', 'does').

       The entire set of Moose::Meta::TypeConstraint::* classes were refactored in this release. If you were
       relying on their internals you should test your code carefully.

0.40
       Documenting the use of '+name' with attributes that come from recently composed roles. It makes
       sense, people are using it, and so why not just officially support it.

       The "Moose::Meta::Class->create" method now supports roles.

       It is now possible to make anonymous enum types by passing "enum" an array reference instead of the
       "enum $name => @values".

0.37
       Added the "make_immutable" keyword as a shortcut to calling "make_immutable" on the meta object. This
       eventually got removed!

       Made "init_arg => undef" work in Moose. This means "do not accept a constructor parameter for this
       attribute".

       Type errors now use the provided message. Prior to this release they didn't.

0.34
       Moose is now a postmodern object system :)

       The Role system was completely refactored. It is 100% backwards compat, but the internals were
       totally changed. If you relied on the internals then you are advised to test carefully.

       Added method exclusion and aliasing for Roles in this release.

       Added the Moose::Util::TypeConstraints::OptimizedConstraints module.

       Passing a list of values to an accessor (which is only expecting one value) used to be silently
       ignored, now it throws an error.

0.26
       Added parameterized types and did a pretty heavy refactoring of the type constraint system.

       Better framework extensibility and better support for "making your own Moose".

0.25 or before
       Honestly, you shouldn't be using versions of Moose that are this old, so many bug fixes and speed
       improvements have been made you would be crazy to not upgrade.

       Also, I am tired of going through the Changelog so I am stopping here, if anyone would like to
       continue this please feel free.

AUTHOR
       Stevan Little <stevan@iinteractive.com>

COPYRIGHT AND LICENSE
       This software is copyright (c) 2011 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.

POD ERRORS
       Hey! The above document had some coding errors, which are explained below:

       Around line 58:
           You forgot a '=back' before '=head1'



perl v5.12.5                                     2011-09-06                          Moose::Manual::Delta(3)