$ +opengl

($=) :: HasSetter s => s a -> a -> IO ()
OpenGL Graphics.Rendering.OpenGL.GL.StateVar
($=!) :: HasSetter s => s a -> a -> IO ()
OpenGL Graphics.Rendering.OpenGL.GL.StateVar
A variant of $= which is strict in the value to be set.
($~) :: (HasGetter v, HasSetter v) => v a -> (a -> a) -> IO ()
OpenGL Graphics.Rendering.OpenGL.GL.StateVar
A modificator convenience function, transforming the contents of a state variable with a given funtion.
($~!) :: (HasGetter v, HasSetter v) => v a -> (a -> a) -> IO ()
OpenGL Graphics.Rendering.OpenGL.GL.StateVar
A variant of $~ which is strict in the transformed value.