thrd_join.c\thread\src - musl - musl - an implementation of the standard library for Linux-based systems

#include <stdint.h>
#include <threads.h>
#include <pthread.h>
int thrd_join(thrd_t t, int *res)
{
 void *pthread_res;
 __pthread_join(t, &pthread_res);
 if (res) *res = (int)(intptr_t)pthread_res;
 return thrd_success;
}