c++中不同类实例内存拷贝

直接上代码：

#include <iostream>#include <cstring>using std::cout;using std::endl;class A1 {        private:                int value;        public:                A1(int value) {                        this->value = value;                }                int get() {                        return this->value;                }};class A2 {        public:                int value;        public:                A2(int value) {                        this->value = value;                }                int get() {                        return this->value;                }};int main(void){        A1 a1(1);        A2 a2(2);        A2 *a2p = &a2;        memcpy(a2p, &a1, sizeof(a2));        cout << a2.get() << endl;        return 0;}