勘误

Item 24: Understand the costs of virtual functions, multiple inheritance, virtual base classes, and RTTI
virtual ~C2(); // redefined function
应为：
virtual ~C2(); // new virtual function

Item 25: Virtualizing constructors and non-member functions
Pseudocode
应为：
Pseudo code

Item 26: Limiting the number of objects of a class
fullyqualified
应为：
fully qualified