superclasses aren't considered because context is no smaller than the instance head
class (AllF f xs, SListI xs) => All (f :: k -> Constraint) (xs :: [k])
instance
#if __GLASGOW_HASKELL__ >= 710
{-# OVERLAPPING #-}
#endif
All SListI xss => SingI (xss :: [[k]]) where
sing = sList
fails with
• Could not deduce (SListI xss)
arising from the superclasses of an instance declaration
from the context: All SListI xss
bound by the instance declaration
at src/Generics/SOP/Constraint.hs:141:3-40
• In the instance declaration for ‘SingI xss’
See https://travis-ci.org/well-typed/generics-sop/jobs/102388817 and https://github.com/phadej/generics-sop/tree/ghc-8.0.1
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.1-rc1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |