Pimpl idiom with inheritance

class A
{
    public:
      A(){pAImpl = new AImpl;};
      void foo(){pAImpl->foo();};
    private:
      AImpl* pAImpl;
};
class AImpl
{
    public:
      void foo(){/*do something*/};
};

class B : public A
{
    public:
      void bar(){pAImpl->bar();};    // Can't do! pAimpl is A's private.
};

class BImpl : public AImpl
{
    public:
      void bar(){/*do something else*/};
};

AImpl * const pimpl

class A
{
    public:
      A(bool DoNew = true){
        if(DoNew)
          pAImpl = new AImpl;
      };
      void foo(){pAImpl->foo();};
    protected:
      void SetpAImpl(AImpl* pImpl) {pAImpl = pImpl;};
    private:
      AImpl* pAImpl;
};
class AImpl
{
    public:
      void foo(){/*do something*/};
};

class B : public A
{
    public:
      B() : A(false){
          pBImpl = new BImpl;
          SetpAImpl(pBImpl);
      };
      void bar(){pBImpl->bar();};
    private:
      BImpl* pBImpl;
};

class BImpl : public AImpl
{
    public:
      void bar(){/*do something else*/};
};