If all you need is a factory method, why do you have to call the new()? Instead of:
my $subobj = $obj->subclass->new();

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it's probably sufficient to call:
my $subobj = $obj->subclass();
# or, better, my $subobj = $obj->subclass_clone();

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Anyway, could you please elaborate a bit regarding the actual usage scenario? It seems that this factory method stiffs the base class, putting a requirement for the base class to "know" about the derived class and making it difficult to use proper inheritance. This would lead to something like:
my $subobj = $obj->clone_into('Class::SubClass');
# ...
sub clone_into {
   my ($self, $subclass) = @_;
   return $subclass->new(%$self);
}

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which leads us to:
my $subobj = Class::SubClass->new(%$obj);

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or, probably more cleanly, to:
my $subobj = Class::SubClass->clone_from($obj);
# ...
sub clone_from {
   my ($package, $base) = @_;
   return $package->new(%$base);
}

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Flavio
perl -ple'$_=reverse' <<<ti.xittelop@oivalf

Don't fool yourself.

In reply to Re: sub classing best practice by polettix
in thread sub classing best practice by cLive ;-)

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