typeid and TypeInfo

Object

Classes that do not explicitly inherit any class, automatically inherit the Object class.

By that definition, the topmost class in any class hierarchy inherits Object:

// Inherits Object indirectly
class StringInstrument : MusicalInstrument {
    // ...
}

Since the topmost class inherits Object, every class indirectly inherits Object as well. In that sense, every class “is an” Object ...