Re: checking a method is not subclassed

You can inspect the value you get from ref($self). If that's not Baz, some other package is calling the method through inheritance (or some other wacky thing). From there, decide what you want to do.

--
brian d foy <brian@stonehenge.com>
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Re^2: checking a method is not subclassed by ikegami (Patriarch) on Feb 02, 2006 at 15:51 UTC
For example, `package Baz; sub new { my ($class) = @_; return bless({}, $class); } sub example { my ($self) = @_; if (ref($self) ne __PACKAGE__) { require Carp; Carp::croak( "Method &" . __PACKAGE__ . "::example must not be inherited" ); } print(ref($self) . " ok\n"); } package Baz::Foo; @ISA = 'Baz'; package main; Baz ->new()->example(); # ok. Baz::Foo->new()->example(); # dies.` [download] outputs `Baz ok Method &Baz::example must not be inherited at !.pl line 28` [download] It's possible to circumvent this by re-blessing the object.	[reply] [d/l] [select]

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Re^2: checking a method is not subclassed
by ikegami (Patriarch) on Feb 02, 2006 at 15:51 UTC

For example,

package Baz;

sub new {
   my ($class) = @_;
   return bless({}, $class);
}

sub example {
   my ($self) = @_;

   if (ref($self) ne __PACKAGE__) {
      require Carp;
      Carp::croak(
         "Method &" . __PACKAGE__ . "::example must not be inherited"
      );
   }

   print(ref($self) . " ok\n");
}


package Baz::Foo;

@ISA = 'Baz';


package main;

Baz     ->new()->example();  # ok.
Baz::Foo->new()->example();  # dies.
[download]

outputs

Baz ok
Method &Baz::example must not be inherited at !.pl line 28
[download]

It's possible to circumvent this by re-blessing the object.

[reply]
[d/l]
[select]