{- |
  Like `cMapM`, but use at most N threads.
-}
cMapMN :: Int -> (a -> IO b) -> [a] -> IO [b]
cMapMN n f = concurrentN n . map f
cMapMN :: Int -> (a -> IO b) -> [a] -> IO [b]
cMapMN n f = concurrentN n . map f
cMapMN n f = concurrentN n . map f