--- /dev/null
+##############################################################################
+# $URL: http://perlcritic.tigris.org/svn/perlcritic/trunk/Perl-Critic/lib/Perl/Critic/Policy/BuiltinFunctions/ProhibitUniversalIsa.pm $
+# $Date: 2008-07-03 10:19:10 -0500 (Thu, 03 Jul 2008) $
+# $Author: clonezone $
+# $Revision: 2489 $
+##############################################################################
+
+package Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa;
+
+use 5.006001;
+use strict;
+use warnings;
+use Readonly;
+
+use Perl::Critic::Utils qw{ :severities :classification };
+use base 'Perl::Critic::Policy';
+
+our $VERSION = '1.088';
+
+#-----------------------------------------------------------------------------
+
+Readonly::Scalar my $DESC => q{UNIVERSAL::isa should not be used as a function};
+Readonly::Scalar my $EXPL => q{Use eval{$obj->isa($pkg)} instead}; ##no critic 'RequireInterp';
+
+#-----------------------------------------------------------------------------
+
+sub supported_parameters { return () }
+sub default_severity { return $SEVERITY_MEDIUM }
+sub default_themes { return qw( core maintenance ) }
+sub applies_to { return 'PPI::Token::Word' }
+
+#-----------------------------------------------------------------------------
+
+sub violates {
+ my ( $self, $elem, undef ) = @_;
+ return if !($elem eq 'isa' || $elem eq 'UNIVERSAL::isa');
+ return if ! is_function_call($elem); # this also permits 'use UNIVERSAL::isa;'
+
+ return $self->violation( $DESC, $EXPL, $elem );
+}
+
+
+1;
+
+__END__
+
+#-----------------------------------------------------------------------------
+
+=pod
+
+=head1 NAME
+
+Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa - Write C<< eval { $foo->isa($pkg) } >> instead of C<UNIVERSAL::isa($foo, $pkg)>.
+
+=head1 AFFILIATION
+
+This Policy is part of the core L<Perl::Critic> distribution.
+
+
+=head1 DESCRIPTION
+
+ print UNIVERSAL::isa($obj, 'Foo::Bar') ? 'yes' : 'no'; #not ok
+ print eval { $obj->isa('Foo::Bar') } ? 'yes' : 'no'; #ok
+
+As of Perl 5.9.3, the use of C<UNIVERSAL::isa> as a function has been
+deprecated and the method form is preferred instead. Formerly, the
+functional form was recommended because it gave valid results even
+when the object was C<undef> or an unblessed scalar. However, the
+functional form makes it impossible for packages to override C<isa()>,
+a technique which is crucial for implementing mock objects and some
+facades.
+
+Another alternative to UNIVERSAL::isa is the C<_INSTANCE> method of
+Param::Util, which is faster.
+
+See the CPAN module L<UNIVERSAL::isa> for an incendiary discussion of
+this topic.
+
+
+=head1 CONFIGURATION
+
+This Policy is not configurable except for the standard options.
+
+
+=head1 SEE ALSO
+
+L<Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalCan>
+
+=head1 AUTHOR
+
+Chris Dolan <cdolan@cpan.org>
+
+=head1 COPYRIGHT
+
+Copyright (c) 2006-2008 Chris Dolan. All rights reserved.
+
+This program is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself. The full text of this license
+can be found in the LICENSE file included with this module.
+
+=cut
+
+# Local Variables:
+# mode: cperl
+# cperl-indent-level: 4
+# fill-column: 78
+# indent-tabs-mode: nil
+# c-indentation-style: bsd
+# End:
+# ex: set ts=8 sts=4 sw=4 tw=78 ft=perl expandtab shiftround :