Problem 58 怎样判断当前程序链接的是多线程版的Glibc还是单线程版的Glibc？

#include <stdio.h>
#include <pthread.h>

int pthread_create(
pthread_t *,
const pthread_attr_t *,
void *(*)(void *),
void *) __attribute__ ((weak));

int main(int argc, char *argv[])
{
if (pthread_create != NULL) {
printf("This is a multi-thread version.\n");
} else {
printf("This is a single-thread version.\n");
}
return 0;
}