-- Randal L. Schwartz, Perl hacker

Well, I wonder in what circumstances I cannot call $x->can('foo') safely.

Only scenario that comes to my mind is when author of class that implements object $x overrides method 'can'. But if such an author would do this, he is supposed to know what he is doing, as 'can' is a well known method together with 'isa'.

When $x isn't a blessed reference!

-- Randal L. Schwartz, Perl hacker

When can't you call $x->can('foo') safely? When $x can't can(), of course!

for $x ('main', undef, \1) {

  if (UNIVERSAL::can($x, 'can')) {

    # ok

    print "can can\n";
    $x->can('foo');
    print "\n";

  } else {

    # error: Can't call method "can" on undefined value/unblessed refe
+rence ...

    print "can't can\n";
    eval { $x->can('foo') };
    print "$@\n";

  }

}
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