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c++qtqt4d-pointer

QExplicitlySharedPointer and inheritance

What is the best way to use QExplicitlySharedPointer and inherited classes. I would like when the BaseClass exits on it's own to have a my d pointer be QExplicitlySharedPointer<BaseClassPrivate> and when I have a Derived class on top of this base class I'd like to have d be a QExplicitlySharedPointer<DerivedClassPrivate>.

I tried making DerivedClassPrivate inherit from BaseClassPrivate, and then make the d pointer protected and re-define the d-pointer in my derived class, but it seems now that I have two copies of the d-pointer both local to the class they are defined in... which is not what I want.

Solution

  • What about this:

    template< typename P = BaseClassPrivate >
class BaseClass
{
public:
  void myBaseFunc() { d->myBaseFunc(); }
protected:
  QExplicitlySharedDataPointer< P > d;
};

class DerivedClass : public BaseClass< DerivedClassPrivate >
{
public:
  void myDerivedFunc() { d->myDerivedFunc(); }
};