Part of the ObjectBasedProgramming pattern language. Discussion occurs on FamilySplitDiscussion.

Original at  http://www.geocities.com/SiliconValley/Foothills/5962/familysplit.htm

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''This pattern is under development.''

'''Intent'''

Provide a strategy to design space efficient instance data. 

'''Motivation'''

Instance data designed with the application of the FamilyFusion pattern can be very space-inefficient under some circumstances. A more space-efficient design is required. 

'''Applicability'''

Use the FamilySplit pattern when 

	* Objects are instantiated from multiple concrete subclasses in a class family, and the subclasses do not share a majority of attributes, and space inefficiency is not acceptable. 

'''Solution'''

The attributes common to all subclasses (or a significant portion) are stored in the primary instance data structure. Creation of auxiliary instance data structure to store the sub-class specific information. 

Extreme case - each subclass would have its own data structure 

'''Consequences'''

The FamilySplit pattern has three important consequences: 

	1. ''Require more sophisticated buffer management.'' 

	2. ''Higher complexity in the polymorphic function.'' 

	3. ''Lower memory consumption.'' 

'''Sample Code'''

This section is to be filled in. 

'''Known Uses'''

This section is to be filled in. 

'''Related Patterns'''

This pattern provides a strategy to design the instance data introduced by the InstanceData pattern. 

The FamilyFusion pattern describes a different technique to design the instance data structure for a class family.