Please reinstate the stream macro

[todoooo]

Some time ago the METAIO_STREAM macro was removed from MetaIO and the new code, which uses std::ifstream/ofstream , breaks unicode compliance in VTK.
See https://gitlab.kitware.com/vtk/vtk/-/merge_requests/6716#note_908828

VTK uses vtksys::ifstream/ofstream to support utf8 path and filenames across all platforms, so please reinstate the macro to allow VTK to function correctly with non-English characters on Windows.

[codeling]

Was the METAIO_STREAM ever something else than a pointer to std?
The vtksys::i/ofstream is a new development I believe?

I have tried to address (a limited subset of) this problem in #113, maybe you would have some comments on my attempted solution there?

[todoooo]

What is needed is to replace Ifstream/iostream in METAIO with their vtksys equivalents, as has been done in VTK and Paraview e.g. https://gitlab.kitware.com/paraview/paraview/-/merge_requests/3850
The METAIO_STREAM macro can be used to achieve this for both VTK and ITK.

[aylward]

+1

Wish it hadn't been removed. @hjmjohnson - do you recall the reason for removing it?