#include <apibase.h>

详细描述

An empty class with a virtual destructor. This can be used for a template parameter of a class template where the parameter sets the base class of the template. This ensures that already the top-level base class has a virtual destructor, which (for usual compilers) yields a simpler class layout than a class inheritance hierarchy where derived classes introduce virtual functions at first. Example:

template < typename S> class MyTemplate : public S { ... }; class MyClass : public MyTemplate<EmptyVirtualClass> { public : virtual void MyFunction(); };