INSTANCE_TYPEABLE0(TyCon,tyconTc,"TyCon")
INSTANCE_TYPEABLE0(TypeRep,typeRepTc,"TypeRep")
INSTANCE_TYPEABLE0(Dynamic,dynamicTc,"Dynamic")
+
+#ifndef __NHC__
+#include "Dynamic.h"
+INSTANCE_TYPEABLE1(IORef,ioRefTc,"IORef")
+#endif
modifyIORef :: IORef a -> (a -> a) -> IO ()
modifyIORef ref f = writeIORef ref . f =<< readIORef ref
+
-- |Atomically modifies the contents of an 'IORef'.
--
-- This function is useful for using 'IORef' in a safe way in a multithreaded
atomicModifyIORef :: IORef a -> (a -> (a,b)) -> IO b
#if defined(__GLASGOW_HASKELL__)
atomicModifyIORef (IORef (STRef r#)) f = IO $ \s -> atomicModifyMutVar# r# f s
+
#elif defined(__HUGS__)
atomicModifyIORef = plainModifyIORef -- Hugs has no preemption
where plainModifyIORef r f = do
a <- readIORef r
case f a of (a',b) -> writeIORef r a' >> return b
#endif
-
-#ifndef __NHC__
-#include "Dynamic.h"
-INSTANCE_TYPEABLE1(IORef,ioRefTc,"IORef")
-#endif