-#define ADD_INTERFACE(cl, a, b, c) \
-bool cl::has_interface(Grob*me)\
-{\
- return me->internal_has_interface (ly_symbol2scm (a));\
-}\
-void cl ## _init_ifaces() {\
- add_interface(a, b, c);\
-}\
-ADD_SCM_INIT_FUNC(cl ## ifaces, cl ## _init_ifaces);\