BoxUnBox.golden

Singletons/BoxUnBox.hs:(0,0)-(0,0): Splicing declarations
    singletons
      [d| unBox :: Box a -> a
          unBox (FBox a) = a
          
          data Box a = FBox a |]
  ======>
    data Box a = FBox a
    unBox :: Box a -> a
    unBox (FBox a) = a
    type FBoxSym0 :: forall a. (~>) a (Box a)
    data FBoxSym0 a0123456789876543210
      where
        FBoxSym0KindInference :: SameKind (Apply FBoxSym0 arg) (FBoxSym1 arg) =>
                                 FBoxSym0 a0123456789876543210
    type instance Apply FBoxSym0 a0123456789876543210 = FBoxSym1 a0123456789876543210
    instance SuppressUnusedWarnings FBoxSym0 where
      suppressUnusedWarnings = snd (((,) FBoxSym0KindInference) ())
    type FBoxSym1 (a0123456789876543210 :: a) =
        FBox a0123456789876543210 :: Box a
    type UnBoxSym0 :: (~>) (Box a) a
    data UnBoxSym0 a0123456789876543210
      where
        UnBoxSym0KindInference :: SameKind (Apply UnBoxSym0 arg) (UnBoxSym1 arg) =>
                                  UnBoxSym0 a0123456789876543210
    type instance Apply UnBoxSym0 a0123456789876543210 = UnBoxSym1 a0123456789876543210
    instance SuppressUnusedWarnings UnBoxSym0 where
      suppressUnusedWarnings = snd (((,) UnBoxSym0KindInference) ())
    type UnBoxSym1 (a0123456789876543210 :: Box a) =
        UnBox a0123456789876543210 :: a
    type UnBox :: Box a -> a
    type family UnBox a where
      UnBox (FBox a) = a
    sUnBox ::
      forall a (t :: Box a). Sing t -> Sing (Apply UnBoxSym0 t :: a)
    sUnBox (SFBox (sA :: Sing a)) = sA
    instance SingI (UnBoxSym0 :: (~>) (Box a) a) where
      sing = (singFun1 @UnBoxSym0) sUnBox
    data SBox :: forall a. Box a -> GHC.Types.Type
      where
        SFBox :: forall a (n :: a). (Sing n) -> SBox (FBox n :: Box a)
    type instance Sing @(Box a) = SBox
    instance SingKind a => SingKind (Box a) where
      type Demote (Box a) = Box (Demote a)
      fromSing (SFBox b) = FBox (fromSing b)
      toSing (FBox (b :: Demote a))
        = case toSing b :: SomeSing a of {
            SomeSing c -> SomeSing (SFBox c) }
    instance SingI n => SingI (FBox (n :: a)) where
      sing = SFBox sing
    instance SingI (FBoxSym0 :: (~>) a (Box a)) where
      sing = (singFun1 @FBoxSym0) SFBox