Theoretical class Requirements
Classes whose instances will be stored in STL containers must have:
- a copy constructor
- operator=
If the instances will be sorted or compared then the class must have:
Practical class requirements
In practice, it may be necessary to please the compiler gods by
defining some functions that are never called. The practical list of
requirements is:
- a default constructor
- a copy constructor
- operator=
- operator==
- operator<