[cfe-dev] clang fails to build templated C++ code that other compilers can

[Douglas Gregor]

On Jul 27, 2010, at 8:25 AM, Sean McBride wrote:

> Hello,
> 
> We are trying to get VTK, an open source project, to build with clang
> (trunk 109432).  It builds with many other compilers on many platforms.
> We have one problem down to the following:
> 
> #include <iostream>
> 
> class vtkArray
> {
> public:
>  void PrintSelf(std::ostream &os) {
>    std::cout << "vtkArray PrintSelf" << std::endl;
>  }
> };
> 
> template<class ThisT, class BaseT>
> class vtkTypeTemplate : public BaseT
> {
> public:
>  typedef BaseT Superclass;
> };
> 
> template<typename T>
> class vtkTypedArray : public vtkTypeTemplate<vtkTypedArray<T>, vtkArray>
> {
> public:
>  void PrintSelf(std::ostream &os);
> };
> 
> template<typename T>
> void vtkTypedArray<T>::PrintSelf(std::ostream &os)
> {
>  this->vtkTypedArray<T>::Superclass::PrintSelf(os); // ERROR
> }
> 
> int main (int argc, char const *argv[])
> {
>  vtkTypedArray<int> array;
>  array.PrintSelf(std::cout);
>  return 0;
> }
> 
> Which gives:
> 
> test.cp:28:27: error: no member named 'Superclass' in 'vtkTypedArray<T>'
>  this->vtkTypedArray<T>::Superclass::PrintSelf(os);
>        ~~~~~~~~~~~~~~~~~~^
> 
> I'm not enough of a C++ expert to know if clang is in error or just more
> strict in some way.  Any language lawyers here? :)

This was a Clang bug (PR7725). It's fixed as of r109582. Thanks for the bug report!

	- Doug