lst-0479-book.cpp
// https://godbolt.org/z/rW4oTPhrG
struct Driver {
virtual void init() = 0;
virtual void done() = 0;
virtual bool send(const char* data, unsigned len) = 0;
};
// https://godbolt.org/z/rW4oTPhrG
struct Driver {
virtual void init() = 0;
virtual void done() = 0;
virtual bool send(const char* data, unsigned len) = 0;
};