This example tests SWIG's ability to handle an unnamed structure
like this :

	typedef struct {
  	     double x,y,z;
        } Vector;

This is relatively common in C codes....   In this case, SWIG
should pick up "Vector" and use it as a structure name to
create :

	Vector_x_set, Vector_x_get
	Vector_y_set, Vector_y_get
	Vector_z_set, Vector_z_get


