 don't need access to the index then 'concatMapOf'  is more flexible in what it accepts.
--
-- @
-- 'concatMapOf' l ≡ 'iconcatMapOf' l '.' 'const'
-- 'iconcatMapOf' ≡ 'ifoldMapOf'
-- @
--
-- @
-- 'iconcatMapOf' :: 'IndexedGetter' i s a     -> (i -> a -> [r]) -> s -> [r]
-- 'iconcatMapOf' :: 'IndexedFold' i s a       -> (i -> a -> [r]) -> s -> [r]
-- 'iconcatMapOf' :: 'IndexedLens'' i s a      -> (i -> a -> [r]) -> s -> [r]
-- 'iconcatMapOf' :: 'IndexedTraversal'' i s a -> (i -> a -> [r]) -> s -> [r]
-- @
iconcatMapOf :: IndexedGetting i [r] s a -> (i -> a -> [r]) -> s -> [r]
iconcatMapOf = ifoldMapOf
{-# INLINE iconcatMapOf #-}

-- | The 'ifindOf' function takes an 'IndexedFold' or 'IndexedTraversal', a predicate that is also
-- supplied the ind
iconcatMapOf :: IndexedGetting i [r] s a -> (i -> a -> [r]) -> s -> [r]
iconcatMapOf = ifoldMapOf
iconcatMapOf = ifoldMapOf