id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
1723	type unsafety with type family + GADT	zunino@…	chak	"Here's ''unsafeCoerce'':
{{{
type family Const a
type instance Const a = ()

data T a where T :: a -> T (Const a)

coerce :: forall a b . a -> b
coerce x = case T x :: T (Const b) of
           T y -> y
}}}
Tested with GHC 6.9.20070918

Maybe, see also #345"	bug	closed	normal	6.10 branch	Compiler (Type checker)	6.8	fixed			Unknown/Multiple	Unknown/Multiple		Unknown	indexed-types/should_fail/GADTwrong1