Panic in conflictInstErr when branched type family instances conflict
This code causes the panic:
{-# LANGUAGE TypeFamilies #-}
type family F a
type instance where
F Int = Int
F Bool = Bool
type instance where
F Int = Char
F Double = Double
Here is the output:
ghc: panic! (the 'impossible' happened)
(GHC version 7.7.20121221 for x86_64-apple-darwin):
conflictInstErr
<<details unavailable>>
Fix on the way...
Trac metadata
Trac field | Value |
---|---|
Version | 7.7 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |