| instance MArray IOUArray a IO => MArray IOUArray (S a) IO where
| However, GHC complains:
|
| /nfs/isd/hdaume/projects/MESumm/Linear2/Linear2.hs:76:
| Non-type variables in constraint: MArray IOUArray a IO
| (Use -fallow-undecidable-instances to permit this)
| But I don't see why t
I'm being hit by undecidable instances, but I can't see why. I read and
reread the GHC docs on MPTCs, but to no avail. This is what I'm trying to
do:
newtype S a = S a
instance MArray IOUArray a IO => MArray IOUArray (S a) IO where
...
the instance declaration is basically just wrapping
