pub fn combine_projections(
p1: Option<&ProjectionRef>,
p2: Option<&ProjectionRef>,
) -> Result<Option<ProjectionRef>>Expand description
Combine two projections.
If p1 is None then there are no changes.
Otherwise, if passed p2 is not None then it is remapped
according to the p1. Otherwise, there are no changes.
§Example
If stored projection is [0, 2] and we call apply_projection([0, 2, 3]),
then the resulting projection will be [0, 3].
§Error
Returns an internal error if p1 contains index that is greater than p2 len.