Implicit constraint on associated type family

test.hs

{-# LANGUAGE
    DerivingStrategies,
    TypeFamilies,
    PatternSynonyms,
    DataKinds
#-}

class (Show (SymbolIdent' p)) => IdentParam p where
  data SymbolIdent' p

data SymbolIdent p where
  SymbolIdent :: IdentParam p => SymbolIdent' p -> SymbolIdent p

deriving stock instance Show (SymbolIdent p)


data IdentParamName
instance IdentParam IdentParamName where
  newtype instance SymbolIdent' IdentParamName = SymbolName' String
    deriving stock (Show)
pattern SymbolName s = SymbolIdent (SymbolName' s)

data IdentParamId
instance IdentParam IdentParamId where
  newtype instance SymbolIdent' IdentParamId = SymbolId' Int
    deriving stock (Show)
pattern SymbolId s = SymbolIdent (SymbolId' s)


data Struct p = Struct (SymbolIdent p)
  deriving stock Show