Panic related to MPTC's and type equality
The following code:
{-# OPTIONS_GHC -fglasgow-exts #-}
class Foo a b where
foo :: a
instance (a ~ ()) => Foo [a] b where
foo = undefined
main = print "hello"
gives this:
ghc-6.8.2: panic! (the 'impossible' happened)
(GHC version 6.8.2 for i386-unknown-linux):
nameModule $dFoo{v aqY}
Trac metadata
Trac field | Value |
---|---|
Version | 6.8.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |