GeneralizedNewtypeDeriving doesn't work with data families
Observe:
{-# LANGUAGE TypeFamilies, GeneralizedNewtypeDeriving #-}
module Bug9 where
class C a where
data D a
instance C Bool where
newtype D Bool = DInt Int deriving (Eq, Show, Num)
The deriving of Num fails, whereas the corresponding standalone newtype works fine.
Trac metadata
Trac field | Value |
---|---|
Version | 6.10.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | lennart@augustsson.net |
Operating system | |
Architecture |