MacOS brew ITK compilation error

[robbietuk]

Related to #531, but possibly seperate

STIR ITK (via HomeBrew) install issue. Setting a clean directory to build in allows for cmake configeration and generation (work around for #531's issue). However, the make fails on:

[  8%] Building CXX object src/IO/CMakeFiles/IO.dir/ITKImageInputFileFormat.cxx.o
/Users/roberttwyman/bin/STIR/STIR/src/IO/ITKImageInputFileFormat.cxx:513:69: error: no member named 'VECTOR' in 'itk::ImageIOBase'
      if (reader->GetImageIO()->GetPixelType() != itk::ImageIOBase::VECTOR) {
                                                  ~~~~~~~~~~~~~~~~~~^
1 error generated.
make[2]: *** [src/IO/CMakeFiles/IO.dir/ITKImageInputFileFormat.cxx.o] Error 1
make[1]: *** [src/IO/CMakeFiles/IO.dir/all] Error 2
make: *** [all] Error 2

[rijobro]

Brew ITK is now v5 (see here), and I think STIR normally requires v4. I wonder if that could be causing you problems.

[robbietuk]

@rijobro Ahh thank you. I installed ITK v4.13 manually allowing for STIR with ITK installation. Brew does not seem to allow ITK v4 to be installed.

[KrisThielemans]

Actually, we should keep up with ITK. I'm sure it worked fine with ITK 5.0, so I guess it's something recently introduced.

Having a look at itk::ImageBaseIO, this seems to be caused by an update that made it in ITK 5.1
InsightSoftwareConsortium/ITK@0dd31a6. Code before that used an ordinary enum, while since then there's some strongly-typed enum stuff. However, from here I'd expected that the code should be backwards compatibly, unless ITK_LEGACY_REMOVE is defined. It's possible that the brew version was configured that way of course (although that would be quite naughty).

In any case, it seems we need to check ITK version and have preprocessor stuff to use the new behaviour from 5.1 onwards.

[KrisThielemans]

Looks like we should use ITK_VERSION_MAJOR and ITK_VERSION_MINOR
https://github.com/InsightSoftwareConsortium/ITK/blob/c2b399eef1248465a848a26231de66a8c9715132/Modules/Core/Common/src/itkConfigure.h.in#L164-L166

and probably itk::ImageIOBase::IOPixelEnum::VECTOR