[vtkusers] Using an octree

[David Doria]

If I include
#include <octree/octree.h>

I get a whole bunch of these errors.

/home/doriad/src/ParaView3/VTK/Utilities/octree/octree.h:9: error:
expected type-specifier before 'vtkstd'
/home/doriad/src/ParaView3/VTK/Utilities/octree/octree.h:9: error:
expected '>' before 'vtkstd'
/home/doriad/src/ParaView3/VTK/Utilities/octree/octree.h:23: error:
ISO C++ forbids declaration of 'octree_node' with no type
/home/doriad/src/ParaView3/VTK/Utilities/octree/octree.h:23: error:
expected ';' before '<' token

Any reason why I can't use the octree class?

-- 
Thanks,

David