testsuite: Assert that testsuite ways are known
[ghc.git] / testsuite / tests / typecheck / should_compile / tc045.hs
1 {-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
2 module ShouldSucceed where
3
4 class C a where
5 op1 :: a -> a
6
7 class (C a) => B a where
8 op2 :: a -> a -> a
9
10 instance (B a) => B [a] where
11 op2 xs ys = xs
12
13 instance C [a] where
14 op1 xs = xs
15
16 {- This was passed by the prototype, but failed hard in the new
17 typechecker with the message
18
19 Fail:No match in theta_class
20 -}