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lib/Class/WeakSingleton.pm  view on Meta::CPAN

YourClass->instance(...) >> are forwarded to C<<
YourClass->_new_instance(...) >>.

Returns a normal reference to the existing, or a newly created
Class::WeakSingleton object. If the C<< ->_new_instance(...) >> method
returns an undefined value then the constructer is deemed to have
failed.

=cut

use Scalar::Util 'weaken';

sub instance {

    # instance()

    my $class = shift;

    # get a reference to the _instance variable in the $class package
    my $instance = do {
        ## no critic
        no strict 'refs';
        \${ $class . "::_instance" };
    };

    return $$instance if defined $$instance;

    my $new_instance = $$instance = $class->_new_instance(@_);

    weaken $$instance;

    return $new_instance;
}

=item $singleton = YourClass->_new_instance(...)

Simple constructor which returns a hash reference blessed into the
current class. May be overloaded to create non-hash objects or handle
any specific initialisation required.