GADTs don't seem to unpack properly

Consider this simple code:

type family Foo a b

data Goof a b where
  Goof :: !(Foo a b :~: Int) -> Goof a b

(:~:) has just one constructor (Refl) with no arguments, so I'd expect it to unpack to a void representation:

GoofConstr :: Foo a b ~N# Int => Goof a b
WGoof :: Foo a b :~: Int -> Goof a b
WGoof eq = case eq of Refl -> GoofConstr

But it doesn't seem to unpack at all.

Trac metadata

Trac field	Value
Version	8.2.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
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Operating system
Architecture

changed milestone to %8.6.1

changed weight to 5

added Tbug Trac import labels

mentioned in commit 9187d5fb

Fixed.

Trac metadata

Trac field	Value
Test case	- → simplCore/should_compile/T14978

Thanks!

Do we want a new ticket to track existentials?

Do we want a new ticket to track existentials?

It's #10016

closed

It looks like this is resolved.

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

added runtime perf label

added Pnormal label