vtkImprintFilter: add a `const` qualifier to operator< (!7853) · Merge requests · VTK / VTK · GitLab

Ben Boeckel requested to merge ben.boeckel/vtk:vtkImprintFilter-macos-failures into master Apr 14, 2021

This is required on macOS. Not sure why other compilers are happy with it.

Introduced in !7818 (merged).