Class::Singleton - Implementation of a "Singleton" class


    use Class::Singleton;

    my $one = Class::Singleton->instance();   # returns a new instance
    my $two = Class::Singleton->instance();   # returns same instance


    This is the Class::Singleton module. A Singleton describes an object class
    that can have only one instance in any system. An example of a Singleton
    might be a print spooler or system registry. This module implements a
    Singleton class from which other classes can be derived. By itself, the
    Class::Singleton module does very little other than manage the instantiation
    of a single object. In deriving a class from Class::Singleton, your module
    will inherit the Singleton instantiation method and can implement whatever
    specific functionality is required.


    See the INSTALL file.


    Copyright (C) 1998 Canon Research Centre Europe Ltd.
    Copyright (C) 1998-2008 Andy Wardley. All rights reserved.
    Copyright (C) 2014, 2020 Steve Hay. All rights reserved.


    This distribution is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself, i.e. under the terms of either the GNU
    General Public License or the Artistic License, as specified in the LICENCE