Class::MakeMethods::Emulator::Singleton - Emulate Class::Singleton


Class::MakeMethods::Emulator::Singleton - Emulate Class::Singleton


  use Class::MakeMethods::Emulator::Singleton; 

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


This module emulates the functionality of Class::Singleton, using Class::MakeMethods to generate similar methods.

You may use it directly, as shown in the SYNOPSIS above,

Furthermore, you may call use Class::MakeMethods::Emulator::Singleton '-take_namespace'; to alias the Class::Singleton namespace to this package, and subsequent calls to the original package will be transparently handled by this emulator. To remove the emulation aliasing, call use Class::MakeMethods::Emulator::Singleton '-release_namespace'.

Caution: This affects all subsequent uses of Class::Singleton in your program, including those in other modules, and might cause unexpected effects.


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 Class::MakeMethods manpage for general information about this distribution.

See the Class::MakeMethods::Emulator manpage for more about this family of subclasses.

See the Class::Singleton manpage for documentation of the original module.

For a description and discussion of the Singleton class, see ``Design Patterns'', Gamma et al, Addison-Wesley, 1995, ISBN 0-201-63361-2.

See new in the Class::MakeMethods::Hash manpage and instance in the Class::MakeMethods::ClassVar manpage for documentation of the created methods.

 Class::MakeMethods::Emulator::Singleton - Emulate Class::Singleton