{-# LANGUAGE DeriveDataTypeable, FlexibleInstances, MultiParamTypeClasses, TemplateHaskell, TypeSynonymInstances #-} module Test where import Cocoa $(declareClass "Test" "NSObject") $(exportClass "Test" "test_" []) -- _Test == nil => True -- _Test # alloc => *** Exception: user error (Message sent to nil: alloc)