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。