With the major revision 2.0 of VTK-m, many items previously marked as
deprecated were removed. If updating to a new version of VTK-m, it is
recommended to first update to VTK-m 1.9, which will include the deprecated
features but provide warnings (with the right compiler) that will point to
the replacement code. Once the deprecations have been fixed, updating to
2.0 should be smoother.
It is possible in a `DataSet` to add a point field (or coordinate system)
that has a different number of points than reported in the cell set.
Likewise for the number of cells in cell fields. This is very bad practice
because it is likely to lead to crashes in worklets that are expecting
arrays of an appropriate length.
Although `DataSet` will still allow this, a warning will be added to the
VTK-m logging to alert users of the inconsistency introduced into the
`DataSet`. Since warnings are by default printed to standard error, users
are likely to see it.
This mechanism sets up CMake variables that allow a user to select which
modules/libraries to create. Dependencies will be tracked down to ensure
that all of a module's dependencies are also enabled.
The modules are also arranged into groups.
Groups allow you to set the enable flag for a group of modules at once.
Thus, if you have several modules that are likely to be used together,
you can create a group for them.
This can be handy in converting user-friendly CMake options (such as
`VTKm_ENABLE_RENDERING`) to the modules that enable that by pointing to
the appropriate group.
