2 package Class::MOP::Class;
7 use Class::MOP::Instance;
8 use Class::MOP::Method::Wrapped;
9 use Class::MOP::Method::Accessor;
10 use Class::MOP::Method::Constructor;
11 use Class::MOP::Class::Immutable::Class::MOP::Class;
14 use Scalar::Util 'blessed', 'weaken';
15 use Sub::Name 'subname';
16 use Devel::GlobalDestruction 'in_global_destruction';
18 our $VERSION = '0.88';
19 $VERSION = eval $VERSION;
20 our $AUTHORITY = 'cpan:STEVAN';
22 use base 'Class::MOP::Module';
32 $package_name = shift;
35 $package_name = $options{package};
38 (defined $package_name && $package_name && !ref($package_name))
39 || confess "You must pass a package name and it cannot be blessed";
41 return Class::MOP::get_metaclass_by_name($package_name)
42 || $class->_construct_class_instance(package => $package_name, @_);
45 sub construct_class_instance {
46 Carp::cluck('The construct_class_instance method has been made private.'
47 . " The public version is deprecated and will be removed in a future release.\n");
48 shift->_construct_class_instance(@_);
51 # NOTE: (meta-circularity)
52 # this is a special form of _construct_instance
53 # (see below), which is used to construct class
54 # meta-object instances for any Class::MOP::*
55 # class. All other classes will use the more
56 # normal &construct_instance.
57 sub _construct_class_instance {
59 my $options = @_ == 1 ? $_[0] : {@_};
60 my $package_name = $options->{package};
61 (defined $package_name && $package_name)
62 || confess "You must pass a package name";
64 # return the metaclass if we have it cached,
65 # and it is still defined (it has not been
66 # reaped by DESTROY yet, which can happen
67 # annoyingly enough during global destruction)
69 if (defined(my $meta = Class::MOP::get_metaclass_by_name($package_name))) {
74 # we need to deal with the possibility
75 # of class immutability here, and then
76 # get the name of the class appropriately
78 ? ($class->is_immutable
79 ? $class->get_mutable_metaclass_name()
83 # now create the metaclass
85 if ($class eq 'Class::MOP::Class') {
86 $meta = $class->_new($options);
90 # it is safe to use meta here because
91 # class will always be a subclass of
92 # Class::MOP::Class, which defines meta
93 $meta = $class->meta->_construct_instance($options)
96 # and check the metaclass compatibility
97 $meta->_check_metaclass_compatibility();
99 Class::MOP::store_metaclass_by_name($package_name, $meta);
102 # we need to weaken any anon classes
103 # so that they can call DESTROY properly
104 Class::MOP::weaken_metaclass($package_name) if $meta->is_anon_class;
111 my $options = @_ == 1 ? $_[0] : {@_};
114 # inherited from Class::MOP::Package
115 'package' => $options->{package},
118 # since the following attributes will
119 # actually be loaded from the symbol
120 # table, and actually bypass the instance
121 # entirely, we can just leave these things
122 # listed here for reference, because they
123 # should not actually have a value associated
125 'namespace' => \undef,
127 # inherited from Class::MOP::Module
129 'authority' => \undef,
131 # defined in Class::MOP::Class
132 'superclasses' => \undef,
136 'attribute_metaclass' =>
137 ( $options->{'attribute_metaclass'} || 'Class::MOP::Attribute' ),
138 'method_metaclass' =>
139 ( $options->{'method_metaclass'} || 'Class::MOP::Method' ),
140 'wrapped_method_metaclass' => (
141 $options->{'wrapped_method_metaclass'}
142 || 'Class::MOP::Method::Wrapped'
144 'instance_metaclass' =>
145 ( $options->{'instance_metaclass'} || 'Class::MOP::Instance' ),
146 'immutable_trait' => (
147 $options->{'immutable_trait'}
148 || 'Class::MOP::Class::Immutable::Trait'
150 'constructor_name' => ( $options->{constructor_name} || 'new' ),
151 'constructor_class' => (
152 $options->{constructor_class} || 'Class::MOP::Method::Constructor'
154 'destructor_class' => $options->{destructor_class},
158 sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
159 sub update_package_cache_flag {
162 # we can manually update the cache number
163 # since we are actually adding the method
164 # to our cache as well. This avoids us
165 # having to regenerate the method_map.
167 $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
171 sub check_metaclass_compatibility {
172 Carp::cluck('The check_metaclass_compatibility method has been made private.'
173 . " The public version is deprecated and will be removed in a future release.\n");
174 shift->_check_metaclass_compatibility(@_);
177 sub _check_metaclass_compatibility {
180 # this is always okay ...
181 return if ref($self) eq 'Class::MOP::Class' &&
182 $self->instance_metaclass eq 'Class::MOP::Instance';
184 my @class_list = $self->linearized_isa;
185 shift @class_list; # shift off $self->name
187 foreach my $superclass_name (@class_list) {
188 my $super_meta = Class::MOP::get_metaclass_by_name($superclass_name) || next;
191 # we need to deal with the possibility
192 # of class immutability here, and then
193 # get the name of the class appropriately
195 = $super_meta->is_immutable
196 ? $super_meta->get_mutable_metaclass_name()
199 ($self->isa($super_meta_type))
200 || confess "The metaclass of " . $self->name . " ("
201 . (ref($self)) . ")" . " is not compatible with the " .
202 "metaclass of its superclass, ".$superclass_name . " ("
203 . ($super_meta_type) . ")";
205 # we also need to check that instance metaclasses
206 # are compatibile in the same the class.
207 ($self->instance_metaclass->isa($super_meta->instance_metaclass))
208 || confess "The instance metaclass for " . $self->name . " (" . ($self->instance_metaclass) . ")" .
209 " is not compatible with the " .
210 "instance metaclass of its superclass, " . $superclass_name . " (" . ($super_meta->instance_metaclass) . ")";
218 # this should be sufficient, if you have a
219 # use case where it is not, write a test and
221 my $ANON_CLASS_SERIAL = 0;
224 # we need a sufficiently annoying prefix
225 # this should suffice for now, this is
226 # used in a couple of places below, so
227 # need to put it up here for now.
228 my $ANON_CLASS_PREFIX = 'Class::MOP::Class::__ANON__::SERIAL::';
232 no warnings 'uninitialized';
233 $self->name =~ /^$ANON_CLASS_PREFIX/;
236 sub create_anon_class {
237 my ($class, %options) = @_;
238 my $package_name = $ANON_CLASS_PREFIX . ++$ANON_CLASS_SERIAL;
239 return $class->create($package_name, %options);
243 # this will only get called for
244 # anon-classes, all other calls
245 # are assumed to occur during
246 # global destruction and so don't
247 # really need to be handled explicitly
251 return if in_global_destruction(); # it'll happen soon anyway and this just makes things more complicated
253 no warnings 'uninitialized';
254 return unless $self->name =~ /^$ANON_CLASS_PREFIX/;
255 # Moose does a weird thing where it replaces the metaclass for
256 # class when fixing metaclass incompatibility. In that case,
257 # we don't want to clean out the namespace now. We can detect
258 # that because Moose will explicitly update the singleton
259 # cache in Class::MOP.
260 my $current_meta = Class::MOP::get_metaclass_by_name($self->name);
261 return if $current_meta ne $self;
263 my ($serial_id) = ($self->name =~ /^$ANON_CLASS_PREFIX(\d+)/);
265 foreach my $key (keys %{$ANON_CLASS_PREFIX . $serial_id}) {
266 delete ${$ANON_CLASS_PREFIX . $serial_id}{$key};
268 delete ${'main::' . $ANON_CLASS_PREFIX}{$serial_id . '::'};
273 # creating classes with MOP ...
276 my ( $class, @args ) = @_;
278 unshift @args, 'package' if @args % 2 == 1;
280 my (%options) = @args;
281 my $package_name = $options{package};
283 (ref $options{superclasses} eq 'ARRAY')
284 || confess "You must pass an ARRAY ref of superclasses"
285 if exists $options{superclasses};
287 (ref $options{attributes} eq 'ARRAY')
288 || confess "You must pass an ARRAY ref of attributes"
289 if exists $options{attributes};
291 (ref $options{methods} eq 'HASH')
292 || confess "You must pass a HASH ref of methods"
293 if exists $options{methods};
295 my (%initialize_options) = @args;
296 delete @initialize_options{qw(
304 my $meta = $class->initialize( $package_name => %initialize_options );
306 $meta->_instantiate_module( $options{version}, $options{authority} );
309 $meta->add_method('meta' => sub {
310 $class->initialize(ref($_[0]) || $_[0]);
313 $meta->superclasses(@{$options{superclasses}})
314 if exists $options{superclasses};
316 # process attributes first, so that they can
317 # install accessors, but locally defined methods
318 # can then overwrite them. It is maybe a little odd, but
319 # I think this should be the order of things.
320 if (exists $options{attributes}) {
321 foreach my $attr (@{$options{attributes}}) {
322 $meta->add_attribute($attr);
325 if (exists $options{methods}) {
326 foreach my $method_name (keys %{$options{methods}}) {
327 $meta->add_method($method_name, $options{methods}->{$method_name});
336 # all these attribute readers will be bootstrapped
337 # away in the Class::MOP bootstrap section
339 sub get_attribute_map { $_[0]->{'attributes'} }
340 sub attribute_metaclass { $_[0]->{'attribute_metaclass'} }
341 sub method_metaclass { $_[0]->{'method_metaclass'} }
342 sub wrapped_method_metaclass { $_[0]->{'wrapped_method_metaclass'} }
343 sub instance_metaclass { $_[0]->{'instance_metaclass'} }
344 sub immutable_trait { $_[0]->{'immutable_trait'} }
345 sub constructor_class { $_[0]->{'constructor_class'} }
346 sub constructor_name { $_[0]->{'constructor_name'} }
347 sub destructor_class { $_[0]->{'destructor_class'} }
349 # Instance Construction & Cloning
355 # we need to protect the integrity of the
356 # Class::MOP::Class singletons here, so we
357 # delegate this to &construct_class_instance
358 # which will deal with the singletons
359 return $class->_construct_class_instance(@_)
360 if $class->name->isa('Class::MOP::Class');
361 return $class->_construct_instance(@_);
364 sub construct_instance {
365 Carp::cluck('The construct_instance method has been made private.'
366 . " The public version is deprecated and will be removed in a future release.\n");
367 shift->_construct_instance(@_);
370 sub _construct_instance {
372 my $params = @_ == 1 ? $_[0] : {@_};
373 my $meta_instance = $class->get_meta_instance();
375 # the code below is almost certainly incorrect
376 # but this is foreign inheritance, so we might
377 # have to kludge it in the end.
378 my $instance = $params->{__INSTANCE__} || $meta_instance->create_instance();
379 foreach my $attr ($class->get_all_attributes()) {
380 $attr->initialize_instance_slot($meta_instance, $instance, $params);
383 # this will only work for a HASH instance type
384 if ($class->is_anon_class) {
385 (Scalar::Util::reftype($instance) eq 'HASH')
386 || confess "Currently only HASH based instances are supported with instance of anon-classes";
388 # At some point we should make this official
389 # as a reserved slot name, but right now I am
390 # going to keep it here.
391 # my $RESERVED_MOP_SLOT = '__MOP__';
392 $instance->{'__MOP__'} = $class;
398 sub get_meta_instance {
400 $self->{'_meta_instance'} ||= $self->_create_meta_instance();
403 sub create_meta_instance {
404 Carp::cluck('The create_meta_instance method has been made private.'
405 . " The public version is deprecated and will be removed in a future release.\n");
406 shift->_create_meta_instance(@_);
409 sub _create_meta_instance {
412 my $instance = $self->instance_metaclass->new(
413 associated_metaclass => $self,
414 attributes => [ $self->get_all_attributes() ],
417 $self->add_meta_instance_dependencies()
418 if $instance->is_dependent_on_superclasses();
425 my $instance = shift;
426 (blessed($instance) && $instance->isa($class->name))
427 || confess "You must pass an instance of the metaclass (" . (ref $class ? $class->name : $class) . "), not ($instance)";
430 # we need to protect the integrity of the
431 # Class::MOP::Class singletons here, they
432 # should not be cloned.
433 return $instance if $instance->isa('Class::MOP::Class');
434 $class->_clone_instance($instance, @_);
438 Carp::cluck('The clone_instance method has been made private.'
439 . " The public version is deprecated and will be removed in a future release.\n");
440 shift->_clone_instance(@_);
443 sub _clone_instance {
444 my ($class, $instance, %params) = @_;
446 || confess "You can only clone instances, ($instance) is not a blessed instance";
447 my $meta_instance = $class->get_meta_instance();
448 my $clone = $meta_instance->clone_instance($instance);
449 foreach my $attr ($class->get_all_attributes()) {
450 if ( defined( my $init_arg = $attr->init_arg ) ) {
451 if (exists $params{$init_arg}) {
452 $attr->set_value($clone, $params{$init_arg});
459 sub rebless_instance {
460 my ($self, $instance, %params) = @_;
462 my $old_metaclass = Class::MOP::class_of($instance);
464 my $old_class = $old_metaclass ? $old_metaclass->name : blessed($instance);
465 $self->name->isa($old_class)
466 || confess "You may rebless only into a subclass of ($old_class), of which (". $self->name .") isn't.";
468 $old_metaclass->rebless_instance_away($instance, $self, %params)
471 my $meta_instance = $self->get_meta_instance();
474 # we use $_[1] here because of t/306_rebless_overload.t regressions on 5.8.8
475 $meta_instance->rebless_instance_structure($_[1], $self);
477 foreach my $attr ( $self->get_all_attributes ) {
478 if ( $attr->has_value($instance) ) {
479 if ( defined( my $init_arg = $attr->init_arg ) ) {
480 $params{$init_arg} = $attr->get_value($instance)
481 unless exists $params{$init_arg};
484 $attr->set_value($instance, $attr->get_value($instance));
489 foreach my $attr ($self->get_all_attributes) {
490 $attr->initialize_instance_slot($meta_instance, $instance, \%params);
496 sub rebless_instance_away {
497 # this intentionally does nothing, it is just a hook
504 my $var_spec = { sigil => '@', type => 'ARRAY', name => 'ISA' };
507 @{$self->get_package_symbol($var_spec)} = @supers;
510 # on 5.8 and below, we need to call
511 # a method to get Perl to detect
512 # a cycle in the class hierarchy
513 my $class = $self->name;
517 # we need to check the metaclass
518 # compatibility here so that we can
519 # be sure that the superclass is
520 # not potentially creating an issues
521 # we don't know about
523 $self->_check_metaclass_compatibility();
524 $self->_superclasses_updated();
526 @{$self->get_package_symbol($var_spec)};
529 sub _superclasses_updated {
531 $self->update_meta_instance_dependencies();
536 my $super_class = $self->name;
538 return @{ $super_class->mro::get_isarev() };
541 sub direct_subclasses {
543 my $super_class = $self->name;
548 } Class::MOP::Class->initialize($_)->superclasses
553 return @{ mro::get_linear_isa( (shift)->name ) };
556 sub class_precedence_list {
558 my $name = $self->name;
560 unless (Class::MOP::IS_RUNNING_ON_5_10()) {
562 # We need to check for circular inheritance here
563 # if we are are not on 5.10, cause 5.8 detects it
564 # late. This will do nothing if all is well, and
565 # blow up otherwise. Yes, it's an ugly hack, better
566 # suggestions are welcome.
568 ($name || return)->isa('This is a test for circular inheritance')
571 # if our mro is c3, we can
572 # just grab the linear_isa
573 if (mro::get_mro($name) eq 'c3') {
574 return @{ mro::get_linear_isa($name) }
578 # we can't grab the linear_isa for dfs
579 # since it has all the duplicates
584 $self->initialize($_)->class_precedence_list()
585 } $self->superclasses()
592 sub wrap_method_body {
593 my ( $self, %args ) = @_;
595 ('CODE' eq ref $args{body})
596 || confess "Your code block must be a CODE reference";
598 $self->method_metaclass->wrap(
599 package_name => $self->name,
605 my ($self, $method_name, $method) = @_;
606 (defined $method_name && $method_name)
607 || confess "You must define a method name";
610 if (blessed($method)) {
611 $body = $method->body;
612 if ($method->package_name ne $self->name) {
613 $method = $method->clone(
614 package_name => $self->name,
616 ) if $method->can('clone');
621 $method = $self->wrap_method_body( body => $body, name => $method_name );
624 $method->attach_to_class($self);
626 $self->get_method_map->{$method_name} = $method;
628 my ( $current_package, $current_name ) = Class::MOP::get_code_info($body);
630 if ( !defined $current_name || $current_name eq '__ANON__' ) {
631 my $full_method_name = ($self->name . '::' . $method_name);
632 subname($full_method_name => $body);
635 $self->add_package_symbol(
636 { sigil => '&', type => 'CODE', name => $method_name },
642 my $fetch_and_prepare_method = sub {
643 my ($self, $method_name) = @_;
644 my $wrapped_metaclass = $self->wrapped_method_metaclass;
646 my $method = $self->get_method($method_name);
647 # if we dont have local ...
649 # try to find the next method
650 $method = $self->find_next_method_by_name($method_name);
651 # die if it does not exist
653 || confess "The method '$method_name' was not found in the inheritance hierarchy for " . $self->name;
654 # and now make sure to wrap it
655 # even if it is already wrapped
656 # because we need a new sub ref
657 $method = $wrapped_metaclass->wrap($method);
660 # now make sure we wrap it properly
661 $method = $wrapped_metaclass->wrap($method)
662 unless $method->isa($wrapped_metaclass);
664 $self->add_method($method_name => $method);
668 sub add_before_method_modifier {
669 my ($self, $method_name, $method_modifier) = @_;
670 (defined $method_name && $method_name)
671 || confess "You must pass in a method name";
672 my $method = $fetch_and_prepare_method->($self, $method_name);
673 $method->add_before_modifier(
674 subname(':before' => $method_modifier)
678 sub add_after_method_modifier {
679 my ($self, $method_name, $method_modifier) = @_;
680 (defined $method_name && $method_name)
681 || confess "You must pass in a method name";
682 my $method = $fetch_and_prepare_method->($self, $method_name);
683 $method->add_after_modifier(
684 subname(':after' => $method_modifier)
688 sub add_around_method_modifier {
689 my ($self, $method_name, $method_modifier) = @_;
690 (defined $method_name && $method_name)
691 || confess "You must pass in a method name";
692 my $method = $fetch_and_prepare_method->($self, $method_name);
693 $method->add_around_modifier(
694 subname(':around' => $method_modifier)
699 # the methods above used to be named like this:
700 # ${pkg}::${method}:(before|after|around)
701 # but this proved problematic when using one modifier
702 # to wrap multiple methods (something which is likely
703 # to happen pretty regularly IMO). So instead of naming
704 # it like this, I have chosen to just name them purely
705 # with their modifier names, like so:
706 # :(before|after|around)
707 # The fact is that in a stack trace, it will be fairly
708 # evident from the context what method they are attached
709 # to, and so don't need the fully qualified name.
713 Carp::cluck("The alias_method method is deprecated. Use add_method instead.\n");
715 shift->add_method(@_);
719 my ($self, $method_name) = @_;
720 (defined $method_name && $method_name)
721 || confess "You must define a method name";
723 exists $self->get_method_map->{$method_name};
727 my ($self, $method_name) = @_;
728 (defined $method_name && $method_name)
729 || confess "You must define a method name";
731 return $self->get_method_map->{$method_name};
735 my ($self, $method_name) = @_;
736 (defined $method_name && $method_name)
737 || confess "You must define a method name";
739 my $removed_method = delete $self->get_method_map->{$method_name};
741 $self->remove_package_symbol(
742 { sigil => '&', type => 'CODE', name => $method_name }
745 $removed_method->detach_from_class if $removed_method;
747 $self->update_package_cache_flag; # still valid, since we just removed the method from the map
749 return $removed_method;
752 sub get_method_list {
754 keys %{$self->get_method_map};
757 sub find_method_by_name {
758 my ($self, $method_name) = @_;
759 (defined $method_name && $method_name)
760 || confess "You must define a method name to find";
761 foreach my $class ($self->linearized_isa) {
762 # fetch the meta-class ...
763 my $meta = $self->initialize($class);
764 return $meta->get_method($method_name)
765 if $meta->has_method($method_name);
770 sub get_all_methods {
772 my %methods = map { %{ $self->initialize($_)->get_method_map } } reverse $self->linearized_isa;
773 return values %methods;
776 sub compute_all_applicable_methods {
777 Carp::cluck('The compute_all_applicable_methods method is deprecated.'
778 . " Use get_all_methods instead.\n");
783 class => $_->package_name,
784 code => $_, # sigh, overloading
786 } shift->get_all_methods(@_);
789 sub get_all_method_names {
792 grep { $uniq{$_}++ == 0 } map { $_->name } $self->get_all_methods;
795 sub find_all_methods_by_name {
796 my ($self, $method_name) = @_;
797 (defined $method_name && $method_name)
798 || confess "You must define a method name to find";
800 foreach my $class ($self->linearized_isa) {
801 # fetch the meta-class ...
802 my $meta = $self->initialize($class);
804 name => $method_name,
806 code => $meta->get_method($method_name)
807 } if $meta->has_method($method_name);
812 sub find_next_method_by_name {
813 my ($self, $method_name) = @_;
814 (defined $method_name && $method_name)
815 || confess "You must define a method name to find";
816 my @cpl = $self->linearized_isa;
817 shift @cpl; # discard ourselves
818 foreach my $class (@cpl) {
819 # fetch the meta-class ...
820 my $meta = $self->initialize($class);
821 return $meta->get_method($method_name)
822 if $meta->has_method($method_name);
831 # either we have an attribute object already
832 # or we need to create one from the args provided
833 my $attribute = blessed($_[0]) ? $_[0] : $self->attribute_metaclass->new(@_);
834 # make sure it is derived from the correct type though
835 ($attribute->isa('Class::MOP::Attribute'))
836 || confess "Your attribute must be an instance of Class::MOP::Attribute (or a subclass)";
838 # first we attach our new attribute
839 # because it might need certain information
840 # about the class which it is attached to
841 $attribute->attach_to_class($self);
843 # then we remove attributes of a conflicting
844 # name here so that we can properly detach
845 # the old attr object, and remove any
846 # accessors it would have generated
847 if ( $self->has_attribute($attribute->name) ) {
848 $self->remove_attribute($attribute->name);
850 $self->invalidate_meta_instances();
853 # get our count of previously inserted attributes and
854 # increment by one so this attribute knows its order
855 my $order = (scalar keys %{$self->get_attribute_map}) - 1;
856 $attribute->_set_insertion_order($order + 1);
858 # then onto installing the new accessors
859 $self->get_attribute_map->{$attribute->name} = $attribute;
861 # invalidate package flag here
865 eval { $attribute->install_accessors() };
869 $self->remove_attribute($attribute->name);
876 sub update_meta_instance_dependencies {
879 if ( $self->{meta_instance_dependencies} ) {
880 return $self->add_meta_instance_dependencies;
884 sub add_meta_instance_dependencies {
887 $self->remove_meta_instance_dependencies;
889 my @attrs = $self->get_all_attributes();
892 my @classes = grep { not $seen{$_->name}++ } map { $_->associated_class } @attrs;
894 foreach my $class ( @classes ) {
895 $class->add_dependent_meta_instance($self);
898 $self->{meta_instance_dependencies} = \@classes;
901 sub remove_meta_instance_dependencies {
904 if ( my $classes = delete $self->{meta_instance_dependencies} ) {
905 foreach my $class ( @$classes ) {
906 $class->remove_dependent_meta_instance($self);
916 sub add_dependent_meta_instance {
917 my ( $self, $metaclass ) = @_;
918 push @{ $self->{dependent_meta_instances} }, $metaclass;
921 sub remove_dependent_meta_instance {
922 my ( $self, $metaclass ) = @_;
923 my $name = $metaclass->name;
924 @$_ = grep { $_->name ne $name } @$_ for $self->{dependent_meta_instances};
927 sub invalidate_meta_instances {
929 $_->invalidate_meta_instance() for $self, @{ $self->{dependent_meta_instances} };
932 sub invalidate_meta_instance {
934 undef $self->{_meta_instance};
938 my ($self, $attribute_name) = @_;
939 (defined $attribute_name && $attribute_name)
940 || confess "You must define an attribute name";
941 exists $self->get_attribute_map->{$attribute_name};
945 my ($self, $attribute_name) = @_;
946 (defined $attribute_name && $attribute_name)
947 || confess "You must define an attribute name";
948 return $self->get_attribute_map->{$attribute_name}
950 # this will return undef anyway, so no need ...
951 # if $self->has_attribute($attribute_name);
955 sub remove_attribute {
956 my ($self, $attribute_name) = @_;
957 (defined $attribute_name && $attribute_name)
958 || confess "You must define an attribute name";
959 my $removed_attribute = $self->get_attribute_map->{$attribute_name};
960 return unless defined $removed_attribute;
961 delete $self->get_attribute_map->{$attribute_name};
962 $self->invalidate_meta_instances();
963 $removed_attribute->remove_accessors();
964 $removed_attribute->detach_from_class();
965 return $removed_attribute;
968 sub get_attribute_list {
970 keys %{$self->get_attribute_map};
973 sub get_all_attributes {
975 my %attrs = map { %{ $self->initialize($_)->get_attribute_map } } reverse $self->linearized_isa;
976 return values %attrs;
979 sub compute_all_applicable_attributes {
980 Carp::cluck('The compute_all_applicable_attributes method has been deprecated.'
981 . " Use get_all_attributes instead.\n");
983 shift->get_all_attributes(@_);
986 sub find_attribute_by_name {
987 my ($self, $attr_name) = @_;
988 foreach my $class ($self->linearized_isa) {
989 # fetch the meta-class ...
990 my $meta = $self->initialize($class);
991 return $meta->get_attribute($attr_name)
992 if $meta->has_attribute($attr_name);
997 # check if we can reinitialize
1001 # if any local attr is defined
1002 return if $self->get_attribute_list;
1004 # or any non-declared methods
1005 if ( my @methods = values %{ $self->get_method_map } ) {
1006 my $metaclass = $self->method_metaclass;
1007 foreach my $method ( @methods ) {
1008 return if $method->isa("Class::MOP::Method::Generated");
1009 # FIXME do we need to enforce this too? return unless $method->isa($metaclass);
1018 sub is_mutable { 1 }
1019 sub is_immutable { 0 }
1021 sub _immutable_options {
1022 my ( $self, @args ) = @_;
1025 inline_accessors => 1,
1026 inline_constructor => 1,
1027 inline_destructor => 0,
1029 immutable_trait => $self->immutable_trait,
1030 constructor_name => $self->constructor_name,
1031 constructor_class => $self->constructor_class,
1032 destructor_class => $self->destructor_class,
1037 sub make_immutable {
1038 my ( $self, @args ) = @_;
1040 if ( $self->is_mutable ) {
1041 $self->_initialize_immutable( $self->_immutable_options(@args) );
1042 $self->_rebless_as_immutable(@args);
1053 if ( $self->is_immutable ) {
1054 my @args = $self->immutable_options;
1055 $self->_rebless_as_mutable();
1056 $self->_remove_inlined_code(@args);
1057 delete $self->{__immutable};
1065 sub _rebless_as_immutable {
1066 my ( $self, @args ) = @_;
1068 $self->{__immutable}{original_class} = ref $self;
1070 bless $self => $self->_immutable_metaclass(@args);
1073 sub _immutable_metaclass {
1074 my ( $self, %args ) = @_;
1076 if ( my $class = $args{immutable_metaclass} ) {
1080 my $trait = $args{immutable_trait} = $self->immutable_trait
1081 || confess "no immutable trait specified for $self";
1083 my $meta_attr = $self->meta->find_attribute_by_name("immutable_trait");
1087 if ( $meta_attr and $trait eq $meta_attr->default ) {
1088 # if the trait is the same as the default we try and pick a
1089 # predictable name for the immutable metaclass
1090 $class_name = 'Class::MOP::Class::Immutable::' . ref($self);
1093 $class_name = join '::', 'Class::MOP::Class::Immutable::CustomTrait',
1094 $trait, 'ForMetaClass', ref($self);
1097 if ( Class::MOP::is_class_loaded($class_name) ) {
1098 if ( $class_name->isa($trait) ) {
1103 "$class_name is already defined but does not inherit $trait";
1107 my @super = ( $trait, ref($self) );
1109 my $meta = $self->initialize($class_name);
1110 $meta->superclasses(@super);
1116 sub _remove_inlined_code {
1119 $self->remove_method( $_->name ) for $self->_inlined_methods;
1121 delete $self->{__immutable}{inlined_methods};
1124 sub _inlined_methods { @{ $_[0]{__immutable}{inlined_methods} || [] } }
1126 sub _add_inlined_method {
1127 my ( $self, $method ) = @_;
1129 push @{ $self->{__immutable}{inlined_methods} ||= [] }, $method;
1132 sub _initialize_immutable {
1133 my ( $self, %args ) = @_;
1135 $self->{__immutable}{options} = \%args;
1136 $self->_install_inlined_code(%args);
1139 sub _install_inlined_code {
1140 my ( $self, %args ) = @_;
1143 $self->_inline_accessors(%args) if $args{inline_accessors};
1144 $self->_inline_constructor(%args) if $args{inline_constructor};
1145 $self->_inline_destructor(%args) if $args{inline_destructor};
1148 sub _rebless_as_mutable {
1151 bless $self, $self->get_mutable_metaclass_name;
1156 sub _inline_accessors {
1159 foreach my $attr_name ( $self->get_attribute_list ) {
1160 $self->get_attribute($attr_name)->install_accessors(1);
1164 sub _inline_constructor {
1165 my ( $self, %args ) = @_;
1167 my $name = $args{constructor_name};
1169 if ( $self->has_method($name) && !$args{replace_constructor} ) {
1170 my $class = $self->name;
1171 warn "Not inlining a constructor for $class since it defines"
1172 . " its own constructor.\n"
1173 . "If you are certain you don't need to inline your"
1174 . " constructor, specify inline_constructor => 0 in your"
1175 . " call to $class->meta->make_immutable\n";
1179 my $constructor_class = $args{constructor_class};
1181 Class::MOP::load_class($constructor_class);
1183 my $constructor = $constructor_class->new(
1187 package_name => $self->name,
1191 if ( $args{replace_constructor} or $constructor->can_be_inlined ) {
1192 $self->add_method( $name => $constructor );
1193 $self->_add_inlined_method($constructor);
1197 sub _inline_destructor {
1198 my ( $self, %args ) = @_;
1200 ( exists $args{destructor_class} && defined $args{destructor_class} )
1201 || confess "The 'inline_destructor' option is present, but "
1202 . "no destructor class was specified";
1204 if ( $self->has_method('DESTROY') && ! $args{replace_destructor} ) {
1205 my $class = $self->name;
1206 warn "Not inlining a destructor for $class since it defines"
1207 . " its own destructor.\n";
1211 my $destructor_class = $args{destructor_class};
1213 Class::MOP::load_class($destructor_class);
1215 return unless $destructor_class->is_needed($self);
1217 my $destructor = $destructor_class->new(
1220 package_name => $self->name,
1224 if ( $args{replace_destructor} or $destructor->can_be_inlined ) {
1225 $self->add_method( 'DESTROY' => $destructor );
1226 $self->_add_inlined_method($destructor);
1238 Class::MOP::Class - Class Meta Object
1242 # assuming that class Foo
1243 # has been defined, you can
1245 # use this for introspection ...
1247 # add a method to Foo ...
1248 Foo->meta->add_method( 'bar' => sub {...} )
1250 # get a list of all the classes searched
1251 # the method dispatcher in the correct order
1252 Foo->meta->class_precedence_list()
1254 # remove a method from Foo
1255 Foo->meta->remove_method('bar');
1257 # or use this to actually create classes ...
1259 Class::MOP::Class->create(
1262 superclasses => ['Foo'],
1264 Class::MOP::Attribute->new('$bar'),
1265 Class::MOP::Attribute->new('$baz'),
1268 calculate_bar => sub {...},
1269 construct_baz => sub {...}
1276 The Class Protocol is the largest and most complex part of the
1277 Class::MOP meta-object protocol. It controls the introspection and
1278 manipulation of Perl 5 classes, and it can create them as well. The
1279 best way to understand what this module can do, is to read the
1280 documentation for each of its methods.
1284 C<Class::MOP::Class> is a subclass of L<Class::MOP::Module>.
1288 =head2 Class construction
1290 These methods all create new C<Class::MOP::Class> objects. These
1291 objects can represent existing classes, or they can be used to create
1292 new classes from scratch.
1294 The metaclass object for a given class is a singleton. If you attempt
1295 to create a metaclass for the same class twice, you will just get the
1300 =item B<< Class::MOP::Class->create($package_name, %options) >>
1302 This method creates a new C<Class::MOP::Class> object with the given
1303 package name. It accepts a number of options.
1309 An optional version number for the newly created package.
1313 An optional authority for the newly created package.
1315 =item * superclasses
1317 An optional array reference of superclass names.
1321 An optional hash reference of methods for the class. The keys of the
1322 hash reference are method names, and values are subroutine references.
1326 An optional array reference of attributes.
1328 An attribute can be passed as an existing L<Class::MOP::Attribute>
1329 object, I<or> or as a hash reference of options which will be passed
1330 to the attribute metaclass's constructor.
1334 =item B<< Class::MOP::Class->create_anon_class(%options) >>
1336 This method works just like C<< Class::MOP::Class->create >> but it
1337 creates an "anonymous" class. In fact, the class does have a name, but
1338 that name is a unique name generated internally by this module.
1340 It accepts the same C<superclasses>, C<methods>, and C<attributes>
1341 parameters that C<create> accepts.
1343 Anonymous classes are destroyed once the metaclass they are attached
1344 to goes out of scope, and will be removed from Perl's internal symbol
1347 All instances of an anonymous class keep a special reference to the
1348 metaclass object, which prevents the metaclass from going out of scope
1349 while any instances exist.
1351 This only works if the instance if based on a hash reference, however.
1353 =item B<< Class::MOP::Class->initialize($package_name, %options) >>
1355 This method will initialize a C<Class::MOP::Class> object for the
1356 named package. Unlike C<create>, this method I<will not> create a new
1359 The purpose of this method is to retrieve a C<Class::MOP::Class>
1360 object for introspecting an existing class.
1362 If an existing C<Class::MOP::Class> object exists for the named
1363 package, it will be returned, and any options provided will be
1366 If the object does not yet exist, it will be created.
1368 The valid options that can be passed to this method are
1369 C<attribute_metaclass>, C<method_metaclass>,
1370 C<wrapped_method_metaclass>, and C<instance_metaclass>. These are all
1371 optional, and default to the appropriate class in the C<Class::MOP>
1376 =head2 Object instance construction and cloning
1378 These methods are all related to creating and/or cloning object
1383 =item B<< $metaclass->clone_object($instance, %params) >>
1385 This method clones an existing object instance. Any parameters you
1386 provide are will override existing attribute values in the object.
1388 This is a convenience method for cloning an object instance, then
1389 blessing it into the appropriate package.
1391 You could implement a clone method in your class, using this method:
1394 my ($self, %params) = @_;
1395 $self->meta->clone_object($self, %params);
1398 =item B<< $metaclass->rebless_instance($instance, %params) >>
1400 This method changes the class of C<$instance> to the metaclass's class.
1402 You can only rebless an instance into a subclass of its current
1403 class. If you pass any additional parameters, these will be treated
1404 like constructor parameters and used to initialize the object's
1405 attributes. Any existing attributes that are already set will be
1408 Before reblessing the instance, this method will call
1409 C<rebless_instance_away> on the instance's current metaclass. This method
1410 will be passed the instance, the new metaclass, and any parameters
1411 specified to C<rebless_instance>. By default, C<rebless_instance_away>
1412 does nothing; it is merely a hook.
1414 =item B<< $metaclass->new_object(%params) >>
1416 This method is used to create a new object of the metaclass's
1417 class. Any parameters you provide are used to initialize the
1418 instance's attributes. A special C<__INSTANCE__> key can be passed to
1419 provide an already generated instance, rather than having Class::MOP
1420 generate it for you. This is mostly useful for using Class::MOP with
1421 foreign classes, which generally generate instances using their own
1424 =item B<< $metaclass->instance_metaclass >>
1426 Returns the class name of the instance metaclass, see
1427 L<Class::MOP::Instance> for more information on the instance
1430 =item B<< $metaclass->get_meta_instance >>
1432 Returns an instance of the C<instance_metaclass> to be used in the
1433 construction of a new instance of the class.
1437 =head2 Informational predicates
1439 These are a few predicate methods for asking information about the
1444 =item B<< $metaclass->is_anon_class >>
1446 This returns true if the class was created by calling C<<
1447 Class::MOP::Class->create_anon_class >>.
1449 =item B<< $metaclass->is_mutable >>
1451 This returns true if the class is still mutable.
1453 =item B<< $metaclass->is_immutable >>
1455 This returns true if the class has been made immutable.
1457 =item B<< $metaclass->is_pristine >>
1459 A class is I<not> pristine if it has non-inherited attributes or if it
1460 has any generated methods.
1464 =head2 Inheritance Relationships
1468 =item B<< $metaclass->superclasses(@superclasses) >>
1470 This is a read-write accessor which represents the superclass
1471 relationships of the metaclass's class.
1473 This is basically sugar around getting and setting C<@ISA>.
1475 =item B<< $metaclass->class_precedence_list >>
1477 This returns a list of all of the class's ancestor classes. The
1478 classes are returned in method dispatch order.
1480 =item B<< $metaclass->linearized_isa >>
1482 This returns a list based on C<class_precedence_list> but with all
1485 =item B<< $metaclass->subclasses >>
1487 This returns a list of all subclasses for this class, even indirect
1490 =item B<< $metaclass->direct_subclasses >>
1492 This returns a list of immediate subclasses for this class, which does not
1493 include indirect subclasses.
1497 =head2 Method introspection and creation
1499 These methods allow you to introspect a class's methods, as well as
1500 add, remove, or change methods.
1502 Determining what is truly a method in a Perl 5 class requires some
1503 heuristics (aka guessing).
1505 Methods defined outside the package with a fully qualified name (C<sub
1506 Package::name { ... }>) will be included. Similarly, methods named
1507 with a fully qualified name using L<Sub::Name> are also included.
1509 However, we attempt to ignore imported functions.
1511 Ultimately, we are using heuristics to determine what truly is a
1512 method in a class, and these heuristics may get the wrong answer in
1513 some edge cases. However, for most "normal" cases the heuristics work
1518 =item B<< $metaclass->get_method($method_name) >>
1520 This will return a L<Class::MOP::Method> for the specified
1521 C<$method_name>. If the class does not have the specified method, it
1524 =item B<< $metaclass->has_method($method_name) >>
1526 Returns a boolean indicating whether or not the class defines the
1527 named method. It does not include methods inherited from parent
1530 =item B<< $metaclass->get_method_map >>
1532 Returns a hash reference representing the methods defined in this
1533 class. The keys are method names and the values are
1534 L<Class::MOP::Method> objects.
1536 =item B<< $metaclass->get_method_list >>
1538 This will return a list of method I<names> for all methods defined in
1541 =item B<< $metaclass->get_all_methods >>
1543 This will traverse the inheritance hierarchy and return a list of all
1544 the L<Class::MOP::Method> objects for this class and its parents.
1546 =item B<< $metaclass->find_method_by_name($method_name) >>
1548 This will return a L<Class::MOP::Method> for the specified
1549 C<$method_name>. If the class does not have the specified method, it
1552 Unlike C<get_method>, this method I<will> look for the named method in
1555 =item B<< $metaclass->get_all_method_names >>
1557 This will return a list of method I<names> for all of this class's
1558 methods, including inherited methods.
1560 =item B<< $metaclass->find_all_methods_by_name($method_name) >>
1562 This method looks for the named method in the class and all of its
1563 parents. It returns every matching method it finds in the inheritance
1564 tree, so it returns a list of methods.
1566 Each method is returned as a hash reference with three keys. The keys
1567 are C<name>, C<class>, and C<code>. The C<code> key has a
1568 L<Class::MOP::Method> object as its value.
1570 The list of methods is distinct.
1572 =item B<< $metaclass->find_next_method_by_name($method_name) >>
1574 This method returns the first method in any superclass matching the
1575 given name. It is effectively the method that C<SUPER::$method_name>
1578 =item B<< $metaclass->add_method($method_name, $method) >>
1580 This method takes a method name and a subroutine reference, and adds
1581 the method to the class.
1583 The subroutine reference can be a L<Class::MOP::Method>, and you are
1584 strongly encouraged to pass a meta method object instead of a code
1585 reference. If you do so, that object gets stored as part of the
1586 class's method map directly. If not, the meta information will have to
1587 be recreated later, and may be incorrect.
1589 If you provide a method object, this method will clone that object if
1590 the object's package name does not match the class name. This lets us
1591 track the original source of any methods added from other classes
1592 (notably Moose roles).
1594 =item B<< $metaclass->remove_method($method_name) >>
1596 Remove the named method from the class. This method returns the
1597 L<Class::MOP::Method> object for the method.
1599 =item B<< $metaclass->method_metaclass >>
1601 Returns the class name of the method metaclass, see
1602 L<Class::MOP::Method> for more information on the method metaclass.
1604 =item B<< $metaclass->wrapped_method_metaclass >>
1606 Returns the class name of the wrapped method metaclass, see
1607 L<Class::MOP::Method::Wrapped> for more information on the wrapped
1612 =head2 Attribute introspection and creation
1614 Because Perl 5 does not have a core concept of attributes in classes,
1615 we can only return information about attributes which have been added
1616 via this class's methods. We cannot discover information about
1617 attributes which are defined in terms of "regular" Perl 5 methods.
1621 =item B<< $metaclass->get_attribute($attribute_name) >>
1623 This will return a L<Class::MOP::Attribute> for the specified
1624 C<$attribute_name>. If the class does not have the specified
1625 attribute, it returns C<undef>.
1627 NOTE that get_attribute does not search superclasses, for that you
1628 need to use C<find_attribute_by_name>.
1630 =item B<< $metaclass->has_attribute($attribute_name) >>
1632 Returns a boolean indicating whether or not the class defines the
1633 named attribute. It does not include attributes inherited from parent
1636 =item B<< $metaclass->get_attribute_map >>
1638 Returns a hash reference representing the attributes defined in this
1639 class. The keys are attribute names and the values are
1640 L<Class::MOP::Attribute> objects.
1642 =item B<< $metaclass->get_attribute_list >>
1644 This will return a list of attributes I<names> for all attributes
1645 defined in this class.
1647 =item B<< $metaclass->get_all_attributes >>
1649 This will traverse the inheritance hierarchy and return a list of all
1650 the L<Class::MOP::Attribute> objects for this class and its parents.
1652 =item B<< $metaclass->find_attribute_by_name($attribute_name) >>
1654 This will return a L<Class::MOP::Attribute> for the specified
1655 C<$attribute_name>. If the class does not have the specified
1656 attribute, it returns C<undef>
1658 Unlike C<get_attribute>, this attribute I<will> look for the named
1659 attribute in superclasses.
1661 =item B<< $metaclass->add_attribute(...) >>
1663 This method accepts either an existing L<Class::MOP::Attribute>
1664 object, or parameters suitable for passing to that class's C<new>
1667 The attribute provided will be added to the class.
1669 Any accessor methods defined by the attribute will be added to the
1670 class when the attribute is added.
1672 If an attribute of the same name already exists, the old attribute
1673 will be removed first.
1675 =item B<< $metaclass->remove_attribute($attribute_name) >>
1677 This will remove the named attribute from the class, and
1678 L<Class::MOP::Attribute> object.
1680 Removing an attribute also removes any accessor methods defined by the
1683 However, note that removing an attribute will only affect I<future>
1684 object instances created for this class, not existing instances.
1686 =item B<< $metaclass->attribute_metaclass >>
1688 Returns the class name of the attribute metaclass for this class. By
1689 default, this is L<Class::MOP::Attribute>. for more information on
1693 =head2 Class Immutability
1695 Making a class immutable "freezes" the class definition. You can no
1696 longer call methods which alter the class, such as adding or removing
1697 methods or attributes.
1699 Making a class immutable lets us optimize the class by inlining some
1700 methods, and also allows us to optimize some methods on the metaclass
1703 After immutabilization, the metaclass object will cache most
1704 informational methods such as C<get_method_map> and
1705 C<get_all_attributes>. Methods which would alter the class, such as
1706 C<add_attribute>, C<add_method>, and so on will throw an error on an
1707 immutable metaclass object.
1709 The immutabilization system in L<Moose> takes much greater advantage
1710 of the inlining features than Class::MOP itself does.
1714 =item B<< $metaclass->make_immutable(%options) >>
1716 This method will create an immutable transformer and uses it to make
1717 the class and its metaclass object immutable.
1719 This method accepts the following options:
1723 =item * inline_accessors
1725 =item * inline_constructor
1727 =item * inline_destructor
1729 These are all booleans indicating whether the specified method(s)
1732 By default, accessors and the constructor are inlined, but not the
1735 =item * immutable_trait
1737 The name of a class which will be used as a parent class for the
1738 metaclass object being made immutable. This "trait" implements the
1739 post-immutability functionality of the metaclass (but not the
1740 transformation itself).
1742 This defaults to L<Class::MOP::Class::Immutable::Trait>.
1744 =item * constructor_name
1746 This is the constructor method name. This defaults to "new".
1748 =item * constructor_class
1750 The name of the method metaclass for constructors. It will be used to
1751 generate the inlined constructor. This defaults to
1752 "Class::MOP::Method::Constructor".
1754 =item * replace_constructor
1756 This is a boolean indicating whether an existing constructor should be
1757 replaced when inlining a constructor. This defaults to false.
1759 =item * destructor_class
1761 The name of the method metaclass for destructors. It will be used to
1762 generate the inlined destructor. This defaults to
1763 "Class::MOP::Method::Denstructor".
1765 =item * replace_destructor
1767 This is a boolean indicating whether an existing destructor should be
1768 replaced when inlining a destructor. This defaults to false.
1772 =item B<< $metaclass->make_mutable >>
1774 Calling this method reverse the immutabilization transformation.
1778 =head2 Method Modifiers
1780 Method modifiers are hooks which allow a method to be wrapped with
1781 I<before>, I<after> and I<around> method modifiers. Every time a
1782 method is called, it's modifiers are also called.
1784 A class can modify its own methods, as well as methods defined in
1787 =head3 How method modifiers work?
1789 Method modifiers work by wrapping the original method and then
1790 replacing it in the class's symbol table. The wrappers will handle
1791 calling all the modifiers in the appropriate order and preserving the
1792 calling context for the original method.
1794 The return values of C<before> and C<after> modifiers are
1795 ignored. This is because their purpose is B<not> to filter the input
1796 and output of the primary method (this is done with an I<around>
1799 This may seem like an odd restriction to some, but doing this allows
1800 for simple code to be added at the beginning or end of a method call
1801 without altering the function of the wrapped method or placing any
1802 extra responsibility on the code of the modifier.
1804 Of course if you have more complex needs, you can use the C<around>
1805 modifier which allows you to change both the parameters passed to the
1806 wrapped method, as well as its return value.
1808 Before and around modifiers are called in last-defined-first-called
1809 order, while after modifiers are called in first-defined-first-called
1810 order. So the call tree might looks something like this:
1822 =head3 What is the performance impact?
1824 Of course there is a performance cost associated with method
1825 modifiers, but we have made every effort to make that cost directly
1826 proportional to the number of modifier features you utilize.
1828 The wrapping method does it's best to B<only> do as much work as it
1829 absolutely needs to. In order to do this we have moved some of the
1830 performance costs to set-up time, where they are easier to amortize.
1832 All this said, our benchmarks have indicated the following:
1834 simple wrapper with no modifiers 100% slower
1835 simple wrapper with simple before modifier 400% slower
1836 simple wrapper with simple after modifier 450% slower
1837 simple wrapper with simple around modifier 500-550% slower
1838 simple wrapper with all 3 modifiers 1100% slower
1840 These numbers may seem daunting, but you must remember, every feature
1841 comes with some cost. To put things in perspective, just doing a
1842 simple C<AUTOLOAD> which does nothing but extract the name of the
1843 method called and return it costs about 400% over a normal method
1848 =item B<< $metaclass->add_before_method_modifier($method_name, $code) >>
1850 This wraps the specified method with the supplied subroutine
1851 reference. The modifier will be called as a method itself, and will
1852 receive the same arguments as are passed to the method.
1854 When the modifier exits, the wrapped method will be called.
1856 The return value of the modifier will be ignored.
1858 =item B<< $metaclass->add_after_method_modifier($method_name, $code) >>
1860 This wraps the specified method with the supplied subroutine
1861 reference. The modifier will be called as a method itself, and will
1862 receive the same arguments as are passed to the method.
1864 When the wrapped methods exits, the modifier will be called.
1866 The return value of the modifier will be ignored.
1868 =item B<< $metaclass->add_around_method_modifier($method_name, $code) >>
1870 This wraps the specified method with the supplied subroutine
1873 The first argument passed to the modifier will be a subroutine
1874 reference to the wrapped method. The second argument is the object,
1875 and after that come any arguments passed when the method is called.
1877 The around modifier can choose to call the original method, as well as
1878 what arguments to pass if it does so.
1880 The return value of the modifier is what will be seen by the caller.
1884 =head2 Introspection
1888 =item B<< Class::MOP::Class->meta >>
1890 This will return a L<Class::MOP::Class> instance for this class.
1892 It should also be noted that L<Class::MOP> will actually bootstrap
1893 this module by installing a number of attribute meta-objects into its
1900 Stevan Little E<lt>stevan@iinteractive.comE<gt>
1902 =head1 COPYRIGHT AND LICENSE
1904 Copyright 2006-2009 by Infinity Interactive, Inc.
1906 L<http://www.iinteractive.com>
1908 This library is free software; you can redistribute it and/or modify
1909 it under the same terms as Perl itself.