Make2.Pair
The pair interface lifted into the monad.
val fst : ('a * 'b, 'e) M.t -> ('a, 'e) M.t
fst (x,y) computes x
fst (x,y)
x
val snd : ('a * 'b, 'e) M.t -> ('b, 'e) M.t
snd (x,y) computes y
snd (x,y)
y