c++ 二进制保存文件

class Stu {
int age;
char* address;
std::string name;
public:
Stu() {
}
Stu(int _age, char* _address, std::string _name) :
age(_age), address(_address), name(_name) {
}
Stu(int _age, std::string _name) :
age(_age), name(_name) {
}
void show() {
using namespace std;
cout << "age:" << age << ",address:" << address << ",name:" << name
<< endl;

}
};
int main() {
const char* fileName = "D://test.txt";
const char* _address = "D://test.txt";
char _address1[80] = "D://test.txt";
ofstream f1(fileName, ios::binary);
Stu st1(12,const_cast<char*>(_address1), "abc");
f1.write((char*) &st1, sizeof(st1));
f1.close();
ifstream f2(fileName, ios::binary);
Stu st2;
f2.read((char*) &st2, sizeof(st2));
st2.show();
return 0;

}