在C中有可能有一个结构或函数的联合吗？

#include <stdio.h>

union Data {
   int i;
   float f;
   char str[20];
};

struct Employee {
   char name[20];
   int age;
   float salary;
};

int main() {
   union Data data;
   struct Employee emp;

   // 使用联合
   data.i = 10;
   data.f = 220.5;
   strcpy(data.str, "Hello");

   printf("Union data: %d\n", data.i);
   printf("Union data: %f\n", data.f);
   printf("Union data: %s\n\n", data.str);

   // 使用结构体
   strcpy(emp.name, "John");
   emp.age = 30;
   emp.salary = 5000.0;

   printf("Employee name: %s\n", emp.name);
   printf("Employee age: %d\n", emp.age);
   printf("Employee salary: %f\n", emp.salary);

   return 0;
}