package CLASS_B;
sub new {
  my $class = shift; # critical here
  bless { @_ }, $class; # blesses to maybe CLASS_A
}
package CLASS_A;
@ISA = qw(CLASS_B);
...
my $object = CLASS_A->new;
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Thank you for pointing out inheritance merlyn!
I saw something like this a few weeks ago... wish I remembered where exactly.


package Class_A;

sub new {

  ## the usual:
  my $class = shift;
  my $self = {};  
  bless $self, $class;
}

sub newB {
  
  my $self = {};  
  bless $self, 'Class_B';
}
[download]

Does this ring any bells?

You mean like a factory method? This is done because we may not know the exact subclass we want to use until runtime. For instance, I've got a project I'm working on now where we want to generate different reports in various formats based on the info out of a database. It works by taking the type of report the user wants and looking up (via a hash) which subclass is for that report type. A factory method then blesses a reference into that class and passes the database info in. From there, the subclass can generate whatever kind of data it wants based on what it gets from the database.