Limit of multiple inheritance in C++

Question

What is the limit of multiple inheritance in C++? i.e, how many classes can a class inherit from? Is it implementation dependent or is there a constraint placed on the number of classes you can inherit from in multiple inheritance?

Answer 1

It's implementation defined. C++11 gives recommended minimums in the Implementation quantities section of the standard:

— Direct and indirect base classes [16 384].
— Direct base classes for a single class [1 024].
[...]
— Direct and indirect virtual bases of a class [1 024].

I'd say that's pretty generous.

Answer 2

Per §10.1:

¹ A class can be derived from any number of base classes. [Note: The use of more than one direct base class is often called multiple inheritance. —end note ]

Everything else depends on compiler's implementation and limitations.