Singletons

• Declare instance, rather than class, members and methods where possible. This both makes it easier to change to a multiple instance design later and permits polymorphic subclassing (remember, static methods can’t be virtual). In essence, use singletons instead of statics when possible for ‘globalesque’ stuff.

• Maintain a private static class pointer variable, sSingleton.

• Provide a static class method, singleton(), that initializes the singleton and returns a reference to it. This method throws an exception if the singleton cannot be created. Each class decides whether subsequent calls to singleton() reattempt to initialize the singleton, return the already initialized instance, or just throw an exception.