Req (preface.Preface_make.Indexed_selective.Over_applicative_via

type ('a, 'index) t = ('a, 'index) Applicative.t

The type held by the Indexed Selective.

val branch : 
  (('a, 'b) Stdlib.Either.t, 'index) t ->
  ('a -> 'c, 'index) t ->
  ('b -> 'c, 'index) t ->
  ('c, 'index) t

branch is like select. It chooses between two effects.