Wrong type for with(Mutable)PrimArrayContents

[Rotaerk]

The withMutablePrimArrayContents and withPrimArrayContents functions take a Ptr a -> m a, which restricts you to only returning an a. Best guess as to why this might have been done is to prevent the return of the pointer itself, but... it prevents the return of everything else too ... Why not change them to (Ptr a -> m b) -> m b?

[chessai]

The withMutablePrimArrayContents and withPrimArrayContents functions take a Ptr a -> m a, which restricts you to only returning an a. Best guess as to why this might have been done is to prevent the return of the pointer itself, but... it prevents the return of everything else too ... Why not change them to (Ptr a -> m b) -> m b?

Makes sense to me - would take a PR

[andrewthad]

Darn. This was a mistake. Fortunately, changing the result type from a to b is nonbreaking even for users of TypeApplications since GHC will infer b to be the last type argument (i.e. forall (m :: Type -> Type) (a :: Type) (b :: Type).). We should release this soon after it's fixed.