[Insight-developers] MetaDataObject Checkins

[Hans Johnson]

Bill,

2)-------------
Can you tell me what part of the specializations is not portable?

The idea behind the itkMetaDataObject is that it can encapsulate
anything.  Because of that I made a default
itk::MetaDataObject<T>::PrintSelf that just printed a string stating
that the type can not print itself.  Then specializations of that
function could be written for cases where print self was well defined.

For example, encapsulating a native C types would be done with the
trivial implementations of:
itk::MetaDataObject<int>
::PrintSelf(std::ostream& os, Indent indent) const
{
    os << indent << this->m_MetaDataObjectValue << std::endl;
}

whereas encapsulating an itk::Image would use:

itk::MetaDataObject<int>
::PrintSelf(std::ostream& os, Indent indent) const
{
    this->m_MetaDataObjectValue->PrintSelf(os,indent);
}

and non itk-application developers could write:
itk::MetaDataObject<MyElephantClass>
::PrintSelf(std::ostream& os, Indent indent) const
{
    std::cout << indent
              << this->m_MetaDataObjectValue->GetTrunk()
              << " "
              << this->m_MetaDataObjectValue->GetEars()
              << " "
              << this->m_MetaDataObjectValue->GetTail()
              << std::endl;
}

The current implementation will have to be changed, because it will work
only for classes that have the operator<< defined to work with ostreams.

If you or anyone else has a portable way of doing this, please let me
know, and I will implement it right away.

Again, sorry about causing all these problems.

Regards,
Hans J. Johnson
hans-johnson@uiowa.edu



Lorensen, William E (Research) wrote:
 > Hans,
 >
 > I corrected a couple of problems with your checkins.
 >
 > 1) itkMetaDataObject.txx did not have #define guards around the code. 
In itk, all .txx files must be
 > includable on their own. To enforce this, the header test generator 
will include the .txx file if one
 > exists. I added guards.
 >
 > 2) I removed the specialization of the printself methods. The usage 
was not portable, but looking
 > into at the code it l;ooks like you don't need the specialization. I 
moved the output into the
 > class's PrintSelf. I lalso removed all the code form the 
itkMetaDataObject.cxx file. I did not remove
 > that file form CMakeLists.txt file because I wasn't sure if you have 
future plans for this file.
 >
 > I made the changes so that we can get some clean continuous builds 
early today. I know that Bill Hoff
 > is ready to check in his vnl changes.
 >
 > Bill
 >
 > _______________________________________________
 > Insight-developers mailing list
 > Insight-developers@public.kitware.com
 > http://public.kitware.com/mailman/listinfo/insight-developers


-- 
===================================================================
Hans J. Johnson                              W294 GH
hans-johnson@uiowa.edu                       Dept. of Psychiatry
http://www.psychiatry.uiowa.edu/~hjohnson    The University of Iowa
(319) 353-8587                               Iowa City, IA 52242
===================================================================