{-# LANGUAGE ForeignFunctionInterface, TypeFamilies, MultiParamTypeClasses, 
             FlexibleInstances, TypeSynonymInstances, 
             EmptyDataDecls, ExistentialQuantification, ScopedTypeVariables #-}

-- module HROOT.Class.Interface where

module HROOT.Class.TArc.Interface where


import Data.Word
import Foreign.ForeignPtr
import HROOT.TypeCast

import HROOT.Class.TArc.RawType

import HROOT.Class.TEllipse.Interface


class (ITEllipse a) => ITArc a where

instance Existable TArc where
  data Exist TArc = forall a. (FPtr a, ITArc a) => ETArc a

upcastTArc :: (FPtr a, ITArc a) => a -> TArc
upcastTArc h = let fh = get_fptr h
                   fh2 :: ForeignPtr RawTArc = castForeignPtr fh
               in cast_fptr_to_obj fh2