# vtkFSLookupTable::MapValue signature changed

**URL:** <https://discourse.slicer.org/t/vtkfslookuptable-mapvalue-signature-changed/1640>\
**Category:** Development\
**Created:** [December 11, 2017, 11:09pm UTC](https://discourse.slicer.org/t/vtkfslookuptable-mapvalue-signature-changed/1640 "2017-12-11T23:09:46Z")\
**Posts on this page:** 1\
**Showing post:** 8

<div class="post-metadata">

**Author:** ![jcfr](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jcfr/32/17825_2.png) [@jcfr](https://discourse.slicer.org/u/jcfr)\
**Post date:** [December 12, 2017, 5:19pm UTC](https://discourse.slicer.org/t/vtkfslookuptable-mapvalue-signature-changed/1640/8 "2017-12-12T17:19:33Z")

</div>

Looking at the change in the master branch of VTK, it looks like the const correctness change is available. See [https://github.com/Kitware/VTK/blame/master/Common/Core/vtkLookupTable.cxx#L740](https://github.com/Kitware/VTK/blame/master/Common/Core/vtkLookupTable.cxx#L740)

If we backport the commit onto the older fork of VTK based of VTK7. See [https://github.com/Slicer/VTK/tree/slicer-v7.1.0-2016-09-23-3b13ad9](https://github.com/Slicer/VTK/tree/slicer-v7.1.0-2016-09-23-3b13ad9)

We wouldn’t have to make the code in Slicer more complex

---

_[View the full topic](https://discourse.slicer.org/t/vtkfslookuptable-mapvalue-signature-changed/1640)._