COMP: Fix the WDocumentation warnings for enum class.

[andrei-sandor]

Used with clang

Replaced \class Doxygen annotations with \enum to avoid warnings

[github-actions]

Thank you for contributing a pull request! 🙏

Welcome to the ITK community! 🤗👋☀️

We are glad you are here and appreciate your contribution. Please keep in mind our community participation guidelines. 📜
More support and guidance on the contribution process can be found in our contributing guide. 📖

This is an automatic message. Allow for time for the ITK community to be able to read the pull request and comment
on it.

[seanm]

@dzenanz @hjmjohnson @N-Dekker : @andrei-sandor is a student working with me this summer, and he's going to take a stab at fixing some warnings in ITK with the goal of being able to enable a few more warning flags on our nightly submissions to cdash.

[N-Dekker]

Thanks @andrei-sandor ! Cool!

I'm interested to hear if these changes will affect the Doxygen output, for example at https://itk.org/Doxygen/html/classitk_1_1CommonEnums.html

The proposed changes look fine to me, but they caused some (undeserved) KWStyle errors. Looking at https://open.cdash.org/tests/1552684315

/home/vsts/work/1/s/Modules/Core/Common/include/itkCommonEnums.h:49: error: comment doesn't have \class
/home/vsts/work/1/s/Modules/Core/Common/include/itkCommonEnums.h:76: error: comment doesn't have \class
/home/vsts/work/1/s/Modules/Core/Common/include/itkCommonEnums.h:100: error: comment doesn't have \class

Probably coming from https://github.com/Kitware/KWStyle/blob/6971e89ec4c763601edf1d0ea0d6f71d42fbca5d/kwsCheckComments.cxx#L203

Do you (or anyone) know how to address those as well?

[dzenanz]

Maybe this condition needs to be updated to consider enum in addition to class? Or we just need to update style overwrite rules to add appropriate exceptions - probably Comments or NameOfClass from this list.

[N-Dekker]

Ideally I think Doxygen should be able to automatically "defer" that CellGeometry is an enum, just by looking at the code. So then the whole line saying * \... CellGeometry might simply be removed. But that may be beyond the scope of this pull request, so for now replacing \class with \enum looks fine to me.

[seanm]

Indeed. We could do this instead. But it would be a massive change touching many files.

Is there some reason ITK is explicitly using \class? Did someone think it was required? Is it a stylistic preference to be explicit? Or...?

[seanm]

Simply allowing doxygen to infer that the comments are attached to the enum below (as @N-Dekker suggested) seems best to me, as it will also eliminate needing to mess with KWStyle. What do you think @dzenanz @thewtex ?

[dzenanz]

If it works, that's fine with me.

[andrei-sandor]

After removing the \enum, the following warning is produced Modules/Core/Common/include/itkFloatingPointExceptions.h:37: error: comment doesn't have \class. What are the possible options? Should a modification be done like here style overwrite rules? Or maybe here this condition (adding an enum might be more complex)?