Function apply_reordering 

pub fn apply_reordering(
    ordering: &mut Option<Vec<usize>>,
    from: usize,
    to: usize,
)

Helper method to be used by clients to help with handling column re-ordering during action processing.

match action {
    Action::ColumnReorder { from, to } => {
        egui_deferred_table::apply_column_reordering(&mut column_ordering, from, to);
    }
    // ...
}

See also:

1. DeferredTableDataSource::column_ordering
2. DeferredTableDataSource::row_ordering
3. Action::ColumnReorder