使用ghc 7.4.2构建gtk2hs-buildtools时,出现以下警告:

c2hs/toplevel/C2HSConfig.hs:110:1:
    Warning: newtype `CInt' is used in an FFI declaration,
             but its constructor is not in scope.
             This will become an error in GHC 7.6.1.
    When checking declaration:
      foreign import ccall safe "static bitfield_direction" bitfield_direction
        :: CInt


即使我有import Foreign.C.Types(CInt),我也会在FFI调用中收到类似的警告。

消除此警告的正确方法是什么?

最佳答案

import Foreign.C.Types(CInt(..))


获取构造函数。

08-05 12:14