1 package Moose::Manual::Delta;
3 # ABSTRACT: Important Changes in Moose
11 This documents any important or noteworthy changes in Moose, with a
12 focus on backwards. This does duplicate data from the F<Changes> file,
13 but aims to provide more details and when possible workarounds.
15 Besides helping keep up with changes, you can also use this document
16 for finding the lowest version of Moose that supported a given
17 feature. If you encounter a problem and have a solution but don't see
18 it documented here, or think we missed an important feature, please
25 =item Roles have their own default attribute metaclass
27 Previously, when a role was applied to a class, it would use the attribute
28 metaclass defined in the class when copying over the attributes in the role.
29 This was wrong, because for instance, using L<MooseX::FollowPBP> in the class
30 would end up renaming all of the accessors generated by the role, some of which
31 may be being called in the role, causing it to break. Roles now keep track of
32 their own attribute metaclass to use by default when being applied to a class
33 (defaulting to Moose::Meta::Attribute). This is modifiable using
34 L<Moose::Util::MetaRole> by passing the C<applied_attribute> key to the
35 C<role_metaroles> option, as in:
37 Moose::Util::MetaRole::apply_metaroles(
40 attribute => ['My::Meta::Role::Attribute'],
43 applied_attribute => ['My::Meta::Role::Attribute'],
47 =item Most deprecated APIs/features are slated for removal in Moose 2.0200
49 Most of the deprecated APIs and features in Moose will start throwing an error
50 in Moose 2.0200. Some of the features will go away entirely, and some will
51 simply throw an error.
53 The things on the chopping block are:
57 =item * Old public methods in Class::MOP and Moose
59 This includes things like C<< Class::MOP::Class->get_attribute_map >>, C<<
60 Class::MOP::Class->construct_instance >>, and many others. These were
61 deprecated in L<Class::MOP> 0.80_01, release on April 5, 2009.
63 These methods will be removed entirely in Moose 2.0200.
65 =item * Old public functions in Class::MOP
67 This include C<Class::MOP::subname>, C<Class::MOP::in_global_destruction>, and
68 the C<Class::MOP::HAS_ISAREV> constant. The first two were deprecated in 0.84,
69 and the last in 0.80. Class::MOP 0.84 was released on May 12, 2009.
71 These functions will be removed entirely in Moose 2.0200.
73 =item * The C<alias> and C<excludes> option for role composition
75 These were renamed to C<-alias> and C<-excludes> in Moose 0.89, released on
78 Passing these will throw an error in Moose 2.0200.
80 =item * The old L<Moose::Util::MetaRole> API
82 This include the C<apply_metaclass_roles()> function, as well as passing the
83 C<for_class> or any key ending in C<_roles> to C<apply_metaroles()>. This was
84 deprecated in Moose 0.93_01, released on January 4, 2010.
86 These will all throw an error in Moose 2.0200.
88 =item * Passing plain lists to C<type()> or C<subtype()>
90 The old API for these functions allowed you to pass a plain list of parameter,
91 rather than a list of hash references (which is what C<as()>, C<where>,
92 etc. return). This was deprecated in Moose 0.71_01, released on February 22,
95 This will throw an error in Moose 2.0200.
97 =item * The Role subtype
99 This subtype was deprecated in Moose 0.84, released on June 26, 2009.
101 This will be removed entirely in Moose 2.0200.
111 =item Configurable stacktraces
113 Classes which use the L<Moose::Error::Default> error class can now have
114 stacktraces disabled by setting the C<MOOSE_ERROR_STYLE> env var to C<croak>.
115 This is experimental, fairly incomplete, and won't work in all cases (because
116 Moose's error system in general is all of these things), but this should allow
117 for reducing at least some of the verbosity in most cases.
125 =item Native Delegations
127 In previous versions of Moose, the Native delegations were created as
128 closures. The generated code was often quite slow compared to doing the same
129 thing by hand. For example, the Array's push delegation ended up doing
132 push @{ $self->$reader() }, @_;
134 If the attribute was created without a reader, the C<$reader> sub reference
135 followed a very slow code path. Even with a reader, this is still slower than
138 Native delegations are now generated as inline code, just like other
139 accessors, so we can access the slot directly.
141 In addition, native traits now do proper constraint checking in all cases. In
142 particular, constraint checking has been improved for array and hash
143 references. Previously, only the I<contained> type (the C<Str> in
144 C<HashRef[Str]>) would be checked when a new value was added to the
145 collection. However, if there was a constraint that applied to the whole
146 value, this was never checked.
148 In addition, coercions are now called on the whole value.
150 The delegation methods now do more argument checking. All of the methods check
151 that a valid number of arguments were passed to the method. In addition, the
152 delegation methods check that the arguments are sane (array indexes, hash
153 keys, numbers, etc.) when applicable. We have tried to emulate the behavior of
154 Perl builtins as much as possible.
156 Finally, triggers are called whenever the value of the attribute is changed by
159 These changes are only likely to break code in a few cases.
161 The inlining code may or may not preserve the original reference when changes
162 are made. In some cases, methods which change the value may replace it
163 entirely. This will break tied values.
165 If you have a typed arrayref or hashref attribute where the type enforces a
166 constraint on the whole collection, this constraint will now be checked. It's
167 possible that code which previously ran without errors will now cause the
168 constraint to fail. However, presumably this is a good thing ;)
170 If you are passing invalid arguments to a delegation which were previously
171 being ignored, these calls will now fail.
173 If your code relied on the trigger only being called for a regular writer,
174 that may cause problems.
176 As always, you are encouraged to test before deploying the latest version of
179 =item Defaults is and default for String, Counter, and Bool
181 A few native traits (String, Counter, Bool) provide default values of "is" and
182 "default" when you created an attribute. Allowing them to provide these values
183 is now deprecated. Supply the value yourself when creating the attribute.
185 =item The C<meta> method
187 Moose and Class::MOP have been cleaned up internally enough to make the
188 C<meta> method that you get by default optional. C<use Moose> and
189 C<use Moose::Role> now can take an additional C<-meta_name> option, which
190 tells Moose what name to use when installing the C<meta> method. Passing
191 C<undef> to this option suppresses generation of the C<meta> method
192 entirely. This should be useful for users of modules which also use a C<meta>
193 method or function, such as L<Curses> or L<Rose::DB::Object>.
201 =item All deprecated features now warn
203 Previously, deprecation mostly consisted of simply saying "X is deprecated" in
204 the Changes file. We were not very consistent about actually warning. Now, all
205 deprecated features still present in Moose actually give a warning. The
206 warning is issued once per calling package. See L<Moose::Deprecated> for more
209 =item You cannot pass C<< coerce => 1 >> unless the attribute's type constraint has a coercion
211 Previously, this was accepted, and it sort of worked, except that if you
212 attempted to set the attribute after the object was created, you would get a
215 Now you will get a warning when you attempt to define the attribute.
217 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> no longer unimport strict and warnings
219 This change was made in 1.05, and has now been reverted. We don't know if the
220 user has explicitly loaded strict or warnings on their own, and unimporting
221 them is just broken in that case.
223 =item Reversed logic when defining which options can be changed
225 L<Moose::Meta::Attribute> now allows all options to be changed in an
226 overridden attribute. The previous behaviour required each option to be
227 whitelisted using the C<legal_options_for_inheritance> method. This method has
228 been removed, and there is a new method, C<illegal_options_for_inheritance>,
229 which can now be used to prevent certain options from being changeable.
231 In addition, we only throw an error if the illegal option is actually
232 changed. If the superclass didn't specify this option at all when defining the
233 attribute, the subclass version can still add it as an option.
235 Example of overriding this in an attribute trait:
237 package Bar::Meta::Attribute;
240 has 'my_illegal_option' => (
245 around illegal_options_for_inheritance => sub {
246 return ( shift->(@_), qw/my_illegal_option/ );
255 =item L<Moose::Object/BUILD> methods are now called when calling C<new_object>
257 Previously, C<BUILD> methods would only be called from C<Moose::Object::new>,
258 but now they are also called when constructing an object via
259 C<Moose::Meta::Class::new_object>. C<BUILD> methods are an inherent part of the
260 object construction process, and this should make C<< $meta->new_object >>
261 actually usable without forcing people to use C<< $meta->name->new >>.
263 =item C<no Moose>, C<no Moose::Role>, and C<no Moose::Exporter> now unimport strict and warnings
265 In the interest of having C<no Moose> clean up everything that C<use Moose>
266 does in the calling scope, C<no Moose> (as well as all other
267 L<Moose::Exporter>-using modules) now unimports strict and warnings.
269 =item Metaclass compatibility checking and fixing should be much more robust
271 The L<metaclass compatibility|Moose/METACLASS COMPATIBILITY AND MOOSE> checking
272 and fixing algorithms have been completely rewritten, in both Class::MOP and
273 Moose. This should resolve many confusing errors when dealing with non-Moose
274 inheritance and with custom metaclasses for things like attributes,
275 constructors, etc. For correct code, the only thing that should require a
276 change is that custom error metaclasses must now inherit from
277 L<Moose::Error::Default>.
285 =item Moose::Meta::TypeConstraint::Class is_subtype_of behavior
287 Earlier versions of L<is_subtype_of|Moose::Meta::TypeConstraint::Class/is_subtype_of>
288 would incorrectly return true when called with itself, its own TC name or
289 its class name as an argument. (i.e. $foo_tc->is_subtype_of('Foo') == 1) This
290 behavior was a caused by C<isa> being checked before the class name. The old
291 behavior can be accessed with L<is_type_of|Moose::Meta::TypeConstraint::Class/is_type_of>
299 =item Moose::Meta::Attribute::Native::Trait::Code no longer creates reader methods by default
301 Earlier versions of L<Moose::Meta::Attribute::Native::Trait::Code> created
302 read-only accessors for the attributes it's been applied to, even if you didn't
303 ask for it with C<< is => 'ro' >>. This incorrect behaviour has now been fixed.
311 =item Moose::Util add_method_modifier behavior
313 add_method_modifier (and subsequently the sugar functions Moose::before,
314 Moose::after, and Moose::around) can now accept arrayrefs, with the same
315 behavior as lists. Types other than arrayref and regexp result in an error.
319 =head1 0.93_01 and 0.94
323 =item Moose::Util::MetaRole API has changed
325 The C<apply_metaclass_roles> function is now called C<apply_metaroles>. The
326 way arguments are supplied has been changed to force you to distinguish
327 between metaroles applied to L<Moose::Meta::Class> (and helpers) versus
328 L<Moose::Meta::Role>.
330 The old API still works, but will warn in a future release, and eventually be
333 =item Moose::Meta::Role has real attributes
335 The attributes returned by L<Moose::Meta::Role> are now instances of the
336 L<Moose::Meta::Role::Attribute> class, instead of bare hash references.
338 =item "no Moose" now removes C<blessed> and C<confess>
340 Moose is now smart enough to know exactly what it exported, even when it
341 re-exports functions from other packages. When you unimport Moose, it will
342 remove these functions from your namespace unless you I<also> imported them
343 directly from their respective packages.
345 If you have a C<no Moose> in your code I<before> you call C<blessed> or
346 C<confess>, your code will break. You can either move the C<no Moose> call
347 later in your code, or explicitly import the relevant functions from the
348 packages that provide them.
350 =item L<Moose::Exporter> is smarter about unimporting re-exports
352 The change above comes from a general improvement to L<Moose::Exporter>. It
353 will now unimport any function it exports, even if that function is a
354 re-export from another package.
356 =item Attributes in roles can no longer override class attributes with "+foo"
358 Previously, this worked more or less accidentally, because role attributes
359 weren't objects. This was never documented, but a few MooseX modules took
362 =item The composition_class_roles attribute in L<Moose::Meta::Role> is now a method
364 This was done to make it possible for roles to alter the the list of
365 composition class roles by applying a method modifiers. Previously, this was
366 an attribute and MooseX modules override it. Since that no longer works, this
369 This I<should> be an attribute, so this may switch back to being an attribute
370 in the future if we can figure out how to make this work.
378 =item Calling $object->new() is no longer deprecated
380 We decided to undeprecate this. Now it just works.
382 =item Both C<get_method_map> and C<get_attribute_map> is deprecated
384 These metaclass methods were never meant to be public, and they are both now
385 deprecated. The work around if you still need the functionality they provided
386 is to iterate over the list of names manually.
388 my %fields = map { $_ => $meta->get_attribute($_) } $meta->get_attribute_list;
390 This was actually a change in L<Class::MOP>, but this version of Moose
391 requires a version of L<Class::MOP> that includes said change.
399 =item Added Native delegation for Code refs
401 See L<Moose::Meta::Attribute::Native::Trait::Code> for details.
403 =item Calling $object->new() is deprecated
405 Moose has long supported this, but it's never really been documented, and we
406 don't think this is a good practice. If you want to construct an object from
407 an existing object, you should provide some sort of alternate constructor like
408 C<< $object->clone >>.
410 Calling C<< $object->new >> now issues a warning, and will be an error in a
413 =item Moose no longer warns if you call C<make_immutable> for a class with mutable ancestors
415 While in theory this is a good thing to warn about, we found so many
416 exceptions to this that doing this properly became quite problematic.
424 =item New Native delegation methods from L<List::Util> and L<List::MoreUtils>
426 In particular, we now have C<reduce>, C<shuffle>, C<uniq>, and C<natatime>.
428 =item The Moose::Exporter with_caller feature is now deprecated
430 Use C<with_meta> instead. The C<with_caller> option will start warning in a
433 =item Moose now warns if you call C<make_immutable> for a class with mutable ancestors
435 This is dangerous because modifying a class after a subclass has been
436 immutabilized will lead to incorrect results in the subclass, due to inlining,
437 caching, etc. This occasionally happens accidentally, when a class loads one
438 of its subclasses in the middle of its class definition, so pointing out that
439 this may cause issues should be helpful. Metaclasses (classes that inherit
440 from L<Class::MOP::Object>) are currently exempt from this check, since at the
441 moment we aren't very consistent about which metaclasses we immutabilize.
443 =item C<enum> and C<duck_type> now take arrayrefs for all forms
445 Previously, calling these functions with a list would take the first element of
446 the list as the type constraint name, and use the remainder as the enum values
447 or method names. This makes the interface inconsistent with the anon-type forms
448 of these functions (which must take an arrayref), and a free-form list where
449 the first value is sometimes special is hard to validate (and harder to give
450 reasonable error messages for). These functions have been changed to take
451 arrayrefs in all their forms - so, C<< enum 'My::Type' => [qw(foo bar)] >> is
452 now the preferred way to create an enum type constraint. The old syntax still
453 works for now, but it will hopefully be deprecated and removed in a future
460 L<Moose::Meta::Attribute::Native> has been moved into the Moose core from
461 L<MooseX::AttributeHelpers>. Major changes include:
465 =item C<traits>, not C<metaclass>
467 Method providers are only available via traits.
469 =item C<handles>, not C<provides> or C<curries>
471 The C<provides> syntax was like core Moose C<< handles => HASHREF >>
472 syntax, but with the keys and values reversed. This was confusing,
473 and AttributeHelpers now uses C<< handles => HASHREF >> in a way that
474 should be intuitive to anyone already familiar with how it is used for
477 The C<curries> functionality provided by AttributeHelpers has been
478 generalized to apply to all cases of C<< handles => HASHREF >>, though
479 not every piece of functionality has been ported (currying with a
480 CODEREF is not supported).
482 =item C<empty> is now C<is_empty>, and means empty, not non-empty
484 Previously, the C<empty> method provided by Arrays and Hashes returned true if
485 the attribute was B<not> empty (no elements). Now it returns true if the
486 attribute B<is> empty. It was also renamed to C<is_empty>, to reflect this.
488 =item C<find> was renamed to C<first>, and C<first> and C<last> were removed
490 L<List::Util> refers to the functionality that we used to provide under C<find>
491 as L<first|List::Util/first>, so that will likely be more familiar (and will
492 fit in better if we decide to add more List::Util functions). C<first> and
493 C<last> were removed, since their functionality is easily duplicated with
496 =item Helpers that take a coderef of one argument now use C<$_>
498 Subroutines passed as the first argument to C<first>, C<map>, and C<grep> now
499 receive their argument in C<$_> rather than as a parameter to the subroutine.
500 Helpers that take a coderef of two or more arguments remain using the argument
501 list (there are technical limitations to using C<$a> and C<$b> like C<sort>
504 See L<Moose::Meta::Attribute::Native> for the new documentation.
508 The C<alias> and C<excludes> role parameters have been renamed to C<-alias>
509 and C<-excludes>. The old names still work, but new code should use the new
510 names, and eventually the old ones will be deprecated and removed.
514 C<< use Moose -metaclass => 'Foo' >> now does alias resolution, just like
515 C<-traits> (and the C<metaclass> and C<traits> options to C<has>).
517 Added two functions C<meta_class_alias> and C<meta_attribute_alias> to
518 L<Moose::Util>, to simplify aliasing metaclasses and metatraits. This is
519 a wrapper around the old
521 package Moose::Meta::Class::Custom::Trait::FooTrait;
522 sub register_implementation { 'My::Meta::Trait' }
528 When an attribute generates I<no> accessors, we now warn. This is to help
529 users who forget the C<is> option. If you really do not want any accessors,
530 you can use C<< is => 'bare' >>. You can maintain back compat with older
531 versions of Moose by using something like:
533 ($Moose::VERSION >= 0.84 ? is => 'bare' : ())
535 When an accessor overwrites an existing method, we now warn. To work around
536 this warning (if you really must have this behavior), you can explicitly
537 remove the method before creating it as an accessor:
541 __PACKAGE__->meta->remove_method('foo');
547 When an unknown option is passed to C<has>, we now warn. You can silence
548 the warning by fixing your code. :)
550 The C<Role> type has been deprecated. On its own, it was useless,
551 since it just checked C<< $object->can('does') >>. If you were using
552 it as a parent type, just call C<role_type('Role::Name')> to create an
553 appropriate type instead.
557 C<use Moose::Exporter;> now imports C<strict> and C<warnings> into packages
562 C<DEMOLISHALL> and C<DEMOLISH> now receive an argument indicating whether or
563 not we are in global destruction.
567 Type constraints no longer run coercions for a value that already matches the
568 constraint. This may affect some (arguably buggy) edge case coercions that
569 rely on side effects in the C<via> clause.
573 L<Moose::Exporter> now accepts the C<-metaclass> option for easily
574 overriding the metaclass (without L<metaclass>). This works for classes
579 Added a C<duck_type> sugar function to L<Moose::Util::TypeConstraints>
580 to make integration with non-Moose classes easier. It simply checks if
581 C<< $obj->can() >> a list of methods.
583 A number of methods (mostly inherited from L<Class::MOP>) have been
584 renamed with a leading underscore to indicate their internal-ness. The
585 old method names will still work for a while, but will warn that the
586 method has been renamed. In a few cases, the method will be removed
587 entirely in the future. This may affect MooseX authors who were using
592 Calling C<subtype> with a name as the only argument now throws an
593 exception. If you want an anonymous subtype do:
595 my $subtype = subtype as 'Foo';
597 This is related to the changes in version 0.71_01.
599 The C<is_needed> method in L<Moose::Meta::Method::Destructor> is now
600 only usable as a class method. Previously, it worked as a class or
601 object method, with a different internal implementation for each
604 The internals of making a class immutable changed a lot in Class::MOP
605 0.78_02, and Moose's internals have changed along with it. The
606 external C<< $metaclass->make_immutable >> method still works the same
611 A mutable class accepted C<< Foo->new(undef) >> without complaint,
612 while an immutable class would blow up with an unhelpful error. Now,
613 in both cases we throw a helpful error instead.
615 This "feature" was originally added to allow for cases such as this:
623 return My::Class->new($args);
625 But we decided this is a bad idea and a little too magical, because it
626 can easily mask real errors.
630 Calling C<type> or C<subtype> without the sugar helpers (C<as>,
631 C<where>, C<message>) is now deprecated.
633 As a side effect, this meant we ended up using Perl prototypes on
634 C<as>, and code like this will no longer work:
636 use Moose::Util::TypeConstraints;
637 use Declare::Constraints::Simple -All;
639 subtype 'ArrayOfInts'
641 => IsArrayRef(IsInt);
643 Instead it must be changed to this:
648 where => IsArrayRef(IsInt)
652 If you want to maintain backwards compat with older versions of Moose,
653 you must explicitly test Moose's C<VERSION>:
655 if ( Moose->VERSION < 0.71_01 ) {
656 subtype 'ArrayOfInts'
658 => IsArrayRef(IsInt);
664 where => IsArrayRef(IsInt)
671 We no longer pass the meta-attribute object as a final argument to
672 triggers. This actually changed for inlined code a while back, but the
673 non-inlined version and the docs were still out of date.
675 If by some chance you actually used this feature, the workaround is
676 simple. You fetch the attribute object from out of the C<$self>
677 that is passed as the first argument to trigger, like so:
683 my ( $self, $value ) = @_;
684 my $attr = $self->meta->find_attribute_by_name('foo');
692 If you created a subtype and passed a parent that Moose didn't know
693 about, it simply ignored the parent. Now it automatically creates the
694 parent as a class type. This may not be what you want, but is less
697 You could declare a name with subtype such as "Foo!Bar". Moose would
698 accept this allowed, but if you used it in a parameterized type such
699 as "ArrayRef[Foo!Bar]" it wouldn't work. We now do some vetting on
700 names created via the sugar functions, so that they can only contain
701 alphanumerics, ":", and ".".
705 Methods created via an attribute can now fulfill a C<requires>
706 declaration for a role. Honestly we don't know why Stevan didn't make
707 this work originally, he was just insane or something.
709 Stack traces from inlined code will now report the line and file as
710 being in your class, as opposed to in Moose guts.
714 When a class does not provide all of a role's required methods, the
715 error thrown now mentions all of the missing methods, as opposed to
716 just the first missing method.
718 Moose will no longer inline a constructor for your class unless it
719 inherits its constructor from Moose::Object, and will warn when it
720 doesn't inline. If you want to force inlining anyway, pass
721 C<< replace_constructor => 1 >> to C<make_immutable>.
723 If you want to get rid of the warning, pass C<< inline_constructor =>
728 Removed the (deprecated) C<make_immutable> keyword.
730 Removing an attribute from a class now also removes delegation
731 (C<handles>) methods installed for that attribute. This is correct
732 behavior, but if you were wrongly relying on it you might get bit.
736 Roles now add methods by calling C<add_method>, not
737 C<alias_method>. They make sure to always provide a method object,
738 which will be cloned internally. This means that it is now possible to
739 track the source of a method provided by a role, and even follow its
740 history through intermediate roles. This means that methods added by
741 a role now show up when looking at a class's method list/map.
743 Parameter and Union args are now sorted, this makes Int|Str the same
744 constraint as Str|Int. Also, incoming type constraint strings are
745 normalized to remove all whitespace differences. This is mostly for
746 internals and should not affect outside code.
748 L<Moose::Exporter> will no longer remove a subroutine that the
749 exporting package re-exports. Moose re-exports the Carp::confess
750 function, among others. The reasoning is that we cannot know whether
751 you have also explicitly imported those functions for your own use, so
752 we err on the safe side and always keep them.
756 C<Moose::init_meta> should now be called as a method.
758 New modules for extension writers, L<Moose::Exporter> and
759 L<Moose::Util::MetaRole>.
763 Implemented metaclass traits (and wrote a recipe for it):
765 use Moose -traits => 'Foo'
767 This should make writing small Moose extensions a little
772 Fixed C<coerce> to accept anon types just like C<subtype> can.
775 coerce $some_anon_type => from 'Str' => via { ... };
779 Added C<BUILDARGS>, a new step in C<< Moose::Object->new() >>.
783 Fixed how the C<< is => (ro|rw) >> works with custom defined
784 C<reader>, C<writer> and C<accessor> options. See the below table for
787 is => ro, writer => _foo # turns into (reader => foo, writer => _foo)
788 is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
789 is => rw, accessor => _foo # turns into (accessor => _foo)
790 is => ro, accessor => _foo # error, accesor is rw
794 The C<before/around/after> method modifiers now support regexp
795 matching of method names. NOTE: this only works for classes, it is
796 currently not supported in roles, but, ... patches welcome.
798 The C<has> keyword for roles now accepts the same array ref form that
799 L<Moose>.pm does for classes.
801 A trigger on a read-only attribute is no longer an error, as it's
802 useful to trigger off of the constructor.
804 Subtypes of parameterizable types now are parameterizable types
809 Fixed issue where C<DEMOLISHALL> was eating the value in C<$@>, and so
810 not working correctly. It still kind of eats them, but so does vanilla
815 Inherited attributes may now be extended without restriction on the
816 type ('isa', 'does').
818 The entire set of Moose::Meta::TypeConstraint::* classes were
819 refactored in this release. If you were relying on their internals you
820 should test your code carefully.
824 Documenting the use of '+name' with attributes that come from recently
825 composed roles. It makes sense, people are using it, and so why not
826 just officially support it.
828 The C<< Moose::Meta::Class->create >> method now supports roles.
830 It is now possible to make anonymous enum types by passing C<enum> an
831 array reference instead of the C<< enum $name => @values >>.
835 Added the C<make_immutable> keyword as a shortcut to calling
836 C<make_immutable> on the meta object. This eventually got removed!
838 Made C<< init_arg => undef >> work in Moose. This means "do not accept
839 a constructor parameter for this attribute".
841 Type errors now use the provided message. Prior to this release they
846 Moose is now a postmodern object system :)
848 The Role system was completely refactored. It is 100% backwards
849 compat, but the internals were totally changed. If you relied on the
850 internals then you are advised to test carefully.
852 Added method exclusion and aliasing for Roles in this release.
854 Added the L<Moose::Util::TypeConstraints::OptimizedConstraints>
857 Passing a list of values to an accessor (which is only expecting one
858 value) used to be silently ignored, now it throws an error.
862 Added parameterized types and did a pretty heavy refactoring of the
863 type constraint system.
865 Better framework extensibility and better support for "making your own
868 =head1 0.25 or before
870 Honestly, you shouldn't be using versions of Moose that are this old,
871 so many bug fixes and speed improvements have been made you would be
872 crazy to not upgrade.
874 Also, I am tired of going through the Changelog so I am stopping here,
875 if anyone would like to continue this please feel free.