in reply to object oriented Perl advice / constructor creation in child class

Well, your example doesn't actually show inheritance. Your constructor creates a "has-a" relationship, because your C1 objects will have one object of each of the classes A, B, C and D as attributes. This is a solid pattern in many cases, but it doesn't give you direct access to the methods of the four classes.

I'd say that today's perlish way to do OOP is Moose or its lightweight cousin Moo, and I definitely recommend those if you have several classes to inherit from. Here's a short example:

# package A; use 5.014; use Moo; sub say_hello { my $self = shift; my ($name) = @_; say "Hello, $name!"; } 1;
# package C; use 5.014; use Moo; has 'name' => (is => 'rw'); sub say_goodbye { my $self = shift; say 'Goodbye, ', $self->name, '!'; } 1;
# package C1; use 5.014; use strict; use warnings; use Moo; extends 'C'; use A; has '_a' => (is => 'ro', default => sub { A->new() }, handles => [qw(say_hello)] ); 1;
Now you can do things like this:
use strict; use warnings; use C1; my $c = C1->new(name => 'John Doe'); $c->say_hello('World'); $c->say_goodbye;

So, your C1 objects have direct access to both the say_hello method from, and the say_goodbye method from

Note that Moo (and Moose) will take care for object constructors: You don't write new methods!

If you want to do object inheritance without an object framework, you do it like this:

package C1; use parent (qw(A B C D));
However, in that case you need to take care for calling parent constructors and conflict resolution yourself, which is why I don't expand on this.