# Support for uint64\_t in Xdmf/HDF5

**URL:** https://discourse.vtk.org/t/support-for-uint64-t-in-xdmf-hdf5/12640
**Category:** Support
**Created:** [November 8, 2023, 7:50am UTC](https://discourse.vtk.org/t/support-for-uint64-t-in-xdmf-hdf5/12640 "2023-11-08T07:50:00Z")
**Posts on this page:** 2
**Page:** 1

<div class="post-metadata">

### Author: ![pkestene](https://discourse.vtk.org/user_avatar/discourse.vtk.org/pkestene/32/7968_2.png) [@pkestene](https://discourse.vtk.org/u/pkestene)
#### Post date: [November 8, 2023, 7:50am UTC](https://discourse.vtk.org/t/support-for-uint64-t-in-xdmf-hdf5/12640/1 "2023-11-08T07:50:00Z")

</div>

Hello,

I’m using Xdmf/hdf5 data format and noticed that 64 bits unsigned integer are not properly supported

- when I load the data set in paraview, paraview doesn’t complain that uint64\_t is not supported, and the data field is filled mostly with wrong values
- i’ve tried to bring uint64\_t support in xdmf, see [https://gitlab.kitware.com/pkestene/xdmf/-/tree/feature/support-uint64?ref\_type=heads](https://gitlab.kitware.com/pkestene/xdmf/-/tree/feature/support-uint64?ref_type=heads)

Can someone review the modifications and/or tell me what is the proper way of bringing uint64 to xdmf ?  
Thank you

---

<div class="post-metadata">

### Author: ![cory.quammen](https://discourse.vtk.org/user_avatar/discourse.vtk.org/cory.quammen/32/6751_2.png) [@cory.quammen](https://discourse.vtk.org/u/cory.quammen)
#### Post date: [December 21, 2023, 10:53pm UTC](https://discourse.vtk.org/t/support-for-uint64-t-in-xdmf-hdf5/12640/2 "2023-12-21T22:53:34Z")

</div>

Closing the loop, I believe this has been resolved via [https://gitlab.kitware.com/vtk/vtk/-/merge\_requests/10726](https://gitlab.kitware.com/vtk/vtk/-/merge_requests/10726).