C++ 联合

联合与结构相似，联合也可以容纳多种不同类型的值，但是每次只能存储这些值中的某一个

#include <iostream>
union mima
{
    unsigned long birthday;
    unsigned short ssn;
    char *pet;

};

int main()
{
    mima mima_1;
    std::cout <<mima_1.birthday << '\n';

    mima_1.pet = "wangcai";
    std::cout << mima_1.pet << "\n";
    std::cout << mima_1.birthday << "\n";

    return 0;
}