     }
 
     inline __device__
-    int verify( float xn, float yn, float sn, int width, int height, int maxlevel ) const
+    bool verify( float xn, float yn, float sn, int width, int height, int maxlevel ) const
     {
         return true;
     }

    }

    inline __device__
    int verify( float xn, float yn, float sn, int width, int height, int maxlevel ) const
    {
        // reject if outside of image bounds or far outside DoG bounds
        return ( ( xn < 0.0f ||

    }

    inline __device__
    bool verify( float xn, float yn, float sn, int width, int height, int maxlevel ) const
    {
        // reject if outside of image bounds or far outside DoG bounds
        return ( ( xn < 0.0f ||
