Yet another solution would be to use Class::Multimethods, and have both constructors named new: 
    package MyClass;
    use Class::Multimethods;

    multimethod new =>('$') => sub {
        my ($class) = @_;
        bless { name => '',
                rank => '',
                cereal_number => '',
              }, $class;
    }

    multimethod new =>('$','$','$','$') => sub {
        my ($class, $name, $rank, $c_num ) = @_;
        bless { name => $name,
                rank => $rank,
                cereal_number => $cnum,
              }, $class;
    }

[download]
BTW, there'll be a new version of Class::Multimethods out in the next month or two that lets you define multimethods like they will (probably) be written in Perl 6: 
    package MyClass;
    use Class::Multimethods::Attributes;

    sub new :multi ($class) {
        bless { name => '',
                rank => '',
                cereal_number => '',
              }, $class;
    }

    sub new :multi ($class, $name, $rank, $c_num) {
        bless { name => $name,
                rank => $rank,
                cereal_number => $cnum,
              }, $class;
    }

[download]
Damian

In reply to Re: OO Perl: calling a constructor within a class by Anonymous Monk
in thread OO Perl: calling a constructor within a class by fx

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