Question

I want to know if it is possible to let compiler issue a warning/error for code as following:

Note:

1. Yea, it is bad programming style and we should avoid such cases – but we are dealing with legacy code and hope compiler can help identify such cases for us.)

2. I prefer a compiler option (VC++) to disable or enable object slicing, if there is any.

class Base{}; class Derived: public Base{};  void Func(Base) {  }  //void Func(Derived) //{ // //}  //main Func(Derived()); 

Here if I comment out the second function, the first function would be called – and the compiler (both VC++ and Gcc) feels comfortable with that.

Is it C++ standard? and can I ask compiler (VC++) to give me a warning when met such code?

Thanks so much!!!

Edit:

Thanks all so much for your help!

I can’t find a compiler option to give a error/warning – I even posted this in MSDN forum for VC++ compiler consultant with no answer. So I am afraid neither gcc nor vc++ implemented this feature.

So add constructor which take derived classes as paramter would be the best solution for now.

Edit

I have submit a feedbak to MS and hope they will fix it soon:

https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=421579

-Baiyan

Answer 1

If you can modify the base class you could do something like:

class Base { public: // not implemented will cause a link error     Base(const Derived &d);     const Base &operator=(const Derived &rhs); }; 

Depending on your compiler that should get you the translation unit, and maybe the function where the slicing is happening.