#define STAT_APPLY(XX)\
    XX(nfds_cnt)\
    XX(nfds_sum)\
    XX(nfds_max)\
    XX(yield_cnt)


#define STAT_STRUCT_FN(name) size_t name;
struct {
    STAT_APPLY(STAT_STRUCT_FN)
} stats;


#define STAT_PRINT_FN(name) printf ( #name ": %zu\n", stats. name);
void report_stat () {
    STAT_APPLY(STAT_PRINT_FN);
}