- int id = find_coll_description(mpi_coll_##cat##_description, name, #cat); \
- cat = reinterpret_cast<ret(*) args>(mpi_coll_##cat##_description[id].coll); \
+ int id = find_coll_description(_XBT_CONCAT3(mpi_coll_, cat, _description), name, _XBT_STRINGIFY(cat)); \
+ cat = reinterpret_cast<ret(*) args>(_XBT_CONCAT3(mpi_coll_, cat, _description)[id].coll); \