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Diffstat (limited to 'testsuite/tests/typecheck/should_fail/T19977b.hs')
-rw-r--r-- | testsuite/tests/typecheck/should_fail/T19977b.hs | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_fail/T19977b.hs b/testsuite/tests/typecheck/should_fail/T19977b.hs new file mode 100644 index 0000000000..6f7bf0f033 --- /dev/null +++ b/testsuite/tests/typecheck/should_fail/T19977b.hs @@ -0,0 +1,21 @@ +{-# LANGUAGE Haskell2010 #-} +{-# LANGUAGE + FlexibleContexts, + FlexibleInstances, + UndecidableInstances, + NoMonomorphismRestriction +#-} + +module T19977b where + +-- See Note [Inferring principal types] in Ghc.Tc.Solver + +class C a +class D a where + d :: a +instance C a => D a where + d = undefined +h = d + +g :: D a => a +g = h |