log value from a Base class when multi-inheritance is involved

multi-inheritance-nightmare.cc

#include <cstdio>
#include <type_traits>  // std::remove_reference

#ifdef USE_TR1_TYPE_TRAITS
template <typename T> using remove_reference = std::tr1::remove_reference<T>;
#else
template <typename T> using remove_reference = std::remove_reference<T>;
#endif

class Foo {
  public:
    template <class Base>
    static Base* GetHandle(void* ptr) {
      Base* handle;
      handle = static_cast<typename remove_reference<decltype(*handle)>::type*>(ptr);

      // I'd like to log a value from Base, but that value only exists on
      // class instances that have Bar in their inheritance chain.
      // There any way to do that?

      return handle;
    }

    void printStuff() {
      fprintf(stderr, "printStuff\n");
    }

  protected:
    virtual ~Foo() { }
};

class Bar {
  public:
    void ImHere() {
      fprintf(stderr, "Bar\n");
    }
  protected:
    virtual ~Bar() { }
};

class Baz : public Foo {
  public:
    void printMe() {
      fprintf(stderr, "Baz\n");
    }
  private:
    ~Baz() { }
};

class Bam : public Bar, public Foo {
  public:
    void printMe() {
      fprintf(stderr, "Bam\n");
    }
  private:
    ~Bam() { }
};


int main() {
  void* baz = new Baz();
  Foo::GetHandle<Baz>(baz)->printMe();
  void* bam = new Bam();
  Foo::GetHandle<Bam>(bam)->ImHere();
}