Q: When should you employ multiple inheritance?

A:There  are  three  acceptable  answers:-  "Rarely," "Never," and  "while  the  problem  domain cannot be modeled accurately any other way." Presume an Asset class, developing class, Vehicle class, and CompanyCar class. All of the company cars are vehicles. Some of the company cars are assets since the organizations own them. Others may be leased. Not all of the assets are vehicles. Money accounts are assets. Real estate storing are assets. Some of the real estate holdings are buildings. Not every building is assets.  Ad infinitum.  While you diagram these relationships, it becomes clear that multiple inheritances are a probable and intuitive way to model this common problem domain. The applicant must understand, though, that multiple inheritance, such as a chainsaw, is a useful tool which has its perils, needs respect, and is best ignored except while nothing else will do.