[derived.classes] (original) (raw)
16 Library introduction [library]
16.4 Library-wide requirements [requirements]
16.4.5 Constraints on programs [constraints]
16.4.5.5 Derived classes [derived.classes]
Virtual member function signatures definedfor a base class in the C++ standardlibrary may be overridden in a derived class defined in the program ([class.virtual]).