Class template function signature syntax

I have a class defined like this:

template< class TBoundingBox >
class BoundingBoxPlaneCalculator
{
  typedef PlaneSpatialObject< TBoundingBox::PointDimension > PlaneSpatialObjectType;
  typedef typename PlaneSpatialObjectType::Pointer      PlaneSpatialObjectPointer;
  std::vector<PlaneSpatialObjectPointer> GetPlanes() const{}
}

If I call the function like:

std::vector<PlaneCalculatorType::PlaneSpatialObjectPointer> planes = planeCalculator->GetPlanes();

It works fine. However, if I change the delcaration to simply

  std::vector<PlaneSpatialObjectPointer> GetPlanes() const;

and then try to define the function outside of the header:

template< class TBoundingBox >
std::vector<BoundingBoxPlaneCalculator< TBoundingBox >::PlaneSpatialObjectPointer>
BoundingBoxPlaneCalculator< TBoundingBox >::GetPlanes() const
{

}

I get

itkBoundingBoxPlaneCalculator.txx:61:82: error: type/value mismatch at argument 1 in template parameter list for ‘template<class _Tp, class _Alloc> class std::vector’
itkBoundingBoxPlaneCalculator.txx:61:82: error:   expected a type, got ‘itk::BoundingBoxPlaneCalculator<TBoundingBox>::PlaneSpatialObjectPointer’

I also tried adding typename, but nothing changed:

template< class TBoundingBox >
std::vector<typename BoundingBoxPlaneCalculator< TBoundingBox >::PlaneSpatialObjectPointer>
BoundingBoxPlaneCalculator< TBoundingBox >::GetPlanes() co开发者_如何学编程nst

Can anyone see what is wrong with this syntax?

Thanks,

David

I pretty much copy-pasted your code but used int to replace a type you didn't define, and this works fine for me (using g++ 4.4):

#include <vector>

template<class TBoundingBox>
class BoundingBoxPlaneCalculator
{
public:
    typedef int* PlaneSpatialObjectPointer;
    std::vector<PlaneSpatialObjectPointer> GetPlanes() const;
};

template<class TBoundingBox>
std::vector<typename BoundingBoxPlaneCalculator<TBoundingBox>::PlaneSpatialObjectPointer>
    BoundingBoxPlaneCalculator<TBoundingBox>::GetPlanes() const {}

int main()
{
    BoundingBoxPlaneCalculator<int> planeCalculator;
    planeCalculator.GetPlanes();
}

The thing is, this doesn't look really different from what you posted, except for the fact that PlaneSpatialObjectPointer wasn't declared in your code. So either there's a typo or missing piece somewhere in your real code, or something else is afoot.

It looks like I just had to add typename in the calling function:

std::vector<typename PlaneCalculatorType::PlaneSpatialObjectPointer> planes = planeCalculator->GetPlanes();

I'm confused why it worked without it when the function was defined inside the class??