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Diffstat (limited to 'testsuite/tests/typecheck/should_fail/tcfail165.hs')
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/tcfail165.hs | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_fail/tcfail165.hs b/testsuite/tests/typecheck/should_fail/tcfail165.hs new file mode 100644 index 0000000000..c23a7f39b4 --- /dev/null +++ b/testsuite/tests/typecheck/should_fail/tcfail165.hs @@ -0,0 +1,16 @@ +{-# OPTIONS -XImpredicativeTypes -fno-warn-deprecated-flags #-} + +module ShouldFail where + +import Control.Concurrent + +-- Attempt to put a polymorphic value in an MVar +-- Fails, but the error message is worth keeping an eye on +-- +-- Actually (Dec 06) it succeeds now +-- +-- In GHC 7.0 it fails again! (and rightly so) + +foo = do var <- newEmptyMVar :: IO (MVar (forall a. Show a => a -> String)) + putMVar var (show :: forall b. Show b => b -> String) + |