• Ryan Scott's avatar
    Fix #16008 with a pinch of addConsistencyConstraints · 3899966e
    Ryan Scott authored
    #16008 happened because we forgot to typecheck nullary
    associated type family instances in a way that's consistent with the
    type variables bound by the parent class. Oops. Easily fixed with a
    use of `checkConsistencyConstraints`.
    Test Plan: make test TEST=T16008
    Reviewers: simonpj, goldfire, bgamari
    Reviewed By: goldfire
    Subscribers: rwbarton, carter
    GHC Trac Issues: #16008
    Differential Revision: https://phabricator.haskell.org/D5435
TcInstDcls.hs 88.3 KB