NAME

       Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa - Write "eval { $foo->isa($pkg) }" instead
       of "UNIVERSAL::isa($foo, $pkg)".

AFFILIATION

       This Policy is part of the core Perl::Critic distribution.

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 "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 "undef" or an unblessed scalar.  However, the functional form makes it impossible for
       packages to override "isa()", a technique which is crucial for implementing mock objects and some
       facades.

       Another alternative to UNIVERSAL::isa is the "_INSTANCE" method of Param::Util, which is faster.

       See the CPAN module UNIVERSAL::isa for an incendiary discussion of this topic.

CONFIGURATION

       This Policy is not configurable except for the standard options.

SEE ALSO

       Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalCan

AUTHOR

       Chris Dolan <cdolan@cpan.org>

COPYRIGHT

       Copyright (c) 2006-2011 Chris Dolan.

       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.

perl v5.24.1                                   Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa(3pm)