Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa(3pm)
                                           User Contributed Perl Documentation


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 v5.38.0                      2023-07-26
             Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa(3pm)