This makes it easier to use task isolation in c++ code. Previously, one either had to check `WITH_TBB` (possibly indirectly through `WITH_OPENVDB`) or one had to use the C function which is less convenient.
This makes it easier to use task isolation in c++ code. Previously, one either had to check `WITH_TBB` (possibly indirectly through `WITH_OPENVDB`) or one had to use the C function which is less convenient.