GeneralizedNewtypeDeriving unusable on associated types
This code:
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
class C c where
data F c r
instance C Int where
newtype F Int r = F (IO r) deriving (Functor)
fails to compile with the following message:
Derived instance `Functor (F Int)'
requires illegal partial application of data type family F
In the newtype instance declaration for `F'
This might be related to #4185 (closed), but then it is marked as fixed in GHC 7.6.2, and I experience my error on 7.6.3.
Trac metadata
Trac field | Value |
---|---|
Version | 7.6.3 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |