In a format string for `{.importcpp.}`, `'1` is the type of the 1st argument,
`'*1` is the 1st base type of the 1st argument, then how to get the 2nd base
type of the 1st argument (e.g. `B` from `Table[A, B]`) ?
- Extracting multiple base types on FFI sls1005
