-- | /O(n)/ Yield 'Just' the index of the first element matching the predicate
-- or 'Nothing' if no such element exists.
findIndex :: G.Vector (Vector k) (Rec (TaggedFunctor Identity) rs)
  => (Rec (TaggedFunctor Identity) rs -> Bool) -> (Vector k) (Rec (TaggedFunctor Identity) rs) -> Maybe Int
findIndex = G.findIndex
findIndex :: G.Vector (Vector k) (Rec (TaggedFunctor Identity) rs)
  => (Rec (TaggedFunctor Identity) rs -> Bool) -> (Vector k) (Rec (TaggedFunctor Identity) rs) -> Maybe Int
findIndex = G.findIndex
findIndex = G.findIndex