[Insight-developers] Filter Input/Output Restrictions

[Brad King]

Hello, all:

During a recent TCON, I proposed creating a standard way of documenting
the restrictions on input/output type arguments for filters.  I've written
an example in the CurvatureFlowImageFilter:

Insight/Code/Algorithms/itkCurvatureFlowImageFilter.h

I chose this class because its restrictions are easy to state, and I knew
what they were because they were already stated in previous parts of the
header's comment.  I'm mostly interested in having a standard place to put
these statements so that they are easy to find among the rest of the
class's documentation.

The format looks like this:

"Input/Output Restrictions:"
" Statement of first restriction..."
" Statement of second restriction..."

Eventually some of the restrictions should be enforced by concept checks.  
This will probably require more pixel traits, though (like whether the
pixel is a real number type).

-Brad