 there.
--
-- >>> Left 4 ^?! _Left
-- 4
--
-- >>> "world" ^?! ix 3
-- 'l'
--
-- @
-- ('^?!') :: s -> 'Getter' s a     -> a
-- ('^?!') :: s -> 'Fold' s a       -> a
-- ('^?!') :: s -> 'Lens'' s a      -> a
-- ('^?!') :: s -> 'Iso'' s a       -> a
-- ('^?!') :: s -> 'Traversal'' s a -> a
-- @
(^?!) :: s -> Getting (Endo a) s a -> a
s ^?! l = foldrOf l const (error "(^?!): empty Fold") s
{-# INLINE (^?!) #-}

-- | Retrieve the 'First' entry of a 'Fold' or 'Travers
(^?!) :: s -> Getting (Endo a) s a -> a
s ^?! l = foldrOf l const (error "(^?!): empty Fold") s
s ^?! l = foldrOf l const (error "(^?!): empty Fold") s