Previously the ApplyPolicy logic was to use the filters
field set, and ignore the policy field set.
But this caused problems, as a filter couldn't express that
it was able to work on all valid types. This caused
certain complex types Vec of Vec's to fail to work properly,
and would cause compile use code paths that would never
be valid for a given policy.
Previously, all declared policies had to implement every tag required by
the policy, even if it was the same as the default. In addition to being
annoying, this makes us less forward compatible because if we add a new
item to the policy any unchanged policy would become incorrect.
This change moves the default policy declarations from the default
policy to PolicyBase. The default policy inherits all of them without
any change. Other policies need only override those that are different
than the default.
Change the VTKM_CONT_EXPORT to VTKM_CONT. (Likewise for EXEC and
EXEC_CONT.) Remove the inline from these macros so that they can be
applied to everything, including implementations in a library.
Because inline is not declared in these modifies, you have to add the
keyword to functions and methods where the implementation is not inlined
in the class.
There was a mismatch in the ApplyPolicy function for CoordinateSystem
objects. The return type declared for the function was not the same as
the type of object actually returned.
Also added a test that actually uses a filter with a CoordinateSystem as
a field to actually test this functionality.
Certain algorithms like VertexClustering only work on certain cellset types.
It is pointless to generate the code paths for structured data cell sets,
when the algorithm can't operate on those dataset types.
