blob: ce87ef1867fa3269142fed4803e34ac3fed33e75 (
plain)
1
2
3
4
5
6
7
8
9
10
|
T5498.hs:30:39: error:
Couldn't match representation of type ‘c a’
with that of ‘c (Down a)’
arising from the coercion of the method ‘intIso’
from type ‘forall (c :: * -> *). c a -> c Int’
to type ‘forall (c :: * -> *). c (Down a) -> c Int’
NB: We cannot know what roles the parameters to ‘c’ have;
we must assume that the role is nominal
When deriving the instance for (IntIso (Down a))
|