[Insight-developers] ConstPointers

[Mark Foskey]

There is what appears to be an inconsistency with SmartPointers and 
const-ness.  You can do:

   ImageType* image = someFilter->GetOutput();
   ImageType::Pointer imageSmart = image;

But you cannot do:

   const ImageType* image = someFilter->GetOutput();
   ImageType::ConstPointer imageSmart = image;

Or at least, I can't do it with MSVC 6.0.  There is no operator=() 
defined for that case.

I believe this has never come up because you rarely take a const image 
as input since you might want to call its Update() method.  Perhaps we 
should explicitly point that out to people trying to write filters.

Is this inconsistency a problem that should be fixed?

-- 
Mark Foskey    (919) 843-5436  Computer-Aided Diagnosis and Display Lab
mark_foskey at unc . edu            Department of Radiology, CB 7515, UNC
http://www . cs . unc . edu/~foskey  Chapel Hill, NC  27599-7515