design-patterns-cpp/flyweight

Flyweight

Flyweight pattern has has structural purpose, applies to objects and uses sharing to support large numbers of fine-grained objects efficiently. The pattern can be used to reduce memory usage when you need to create a large number of similar objects.

When to use

• when one instance of a class can be used to provide many "virtual instances"
• when all of the following are true
• an application uses a large number of objects
• storage costs are high because of the sheer quantity of objects
• most object state can be made extrinsic
• many groups of objects may be replaced by relatively few shared objects once extrinsic state is removed
• the application doesn't depend on object identity