
176 ◾ Software Essentials
and predict future demands. Standard review includes breadth of the pub-
lic interface, anticipated reuse, stability, memory usage, and cost (size).
Documentation details about an object’s relationship to a subobject include:
Accessibility
Private
Full or partial access
Echoed functionality
Association
Temporary or permanent
Delayed instantiation
Stable but replaceable
Cardinality
Fixed by class design
Same for all objects
Fixed at instantiation
Stable for object lifetime
Variable within object lifetime
Ownership
Owned (internal responsibility)
External resource
Shared, transferable
We evaluate the merit of inheritance in more det ...