Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalCan - Write 'eval { $foo->can($name) }' instead of 'UNIVERSAL::can($foo, $name)'.

NAME AFFILIATION DESCRIPTION CONFIGURATION SEE ALSO AUTHOR COPYRIGHT

NAME

Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalCan − Write "eval { $foo−>can($name) }" instead of "UNIVERSAL::can($foo, $name)".

AFFILIATION

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

DESCRIPTION

print UNIVERSAL::can($obj, 'Foo::Bar') ? 'yes' : 'no'; #not ok
print eval { $obj−>can('Foo::Bar') } ? 'yes' : 'no'; #ok

As of Perl 5.9.3, the use of UNIVERSAL::can 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 can(), a technique which is crucial for implementing mock objects and some facades.

See UNIVERSAL::can for a more thorough discussion of this topic.