对象隐式转换，复制构造函数和重载等号运算符的区别

#include<iostream>#include<string.h>using namespace std;class A{public:    A(char* username) {        cnt++;        cout << cnt << endl;        name = new char[strlen(username)];        strcpy(name,username);        cout << username << endl;    }    A(const A& cp) {        /*name = new char[strlen(cp.name)];        strcpy(this->name,cp.name);*/        name = cp.name;        cout << cnt << endl;        cout << "this name is "<< this->name << "\t" << cp.name << endl;    }    A& operator= (const A& cp) {        name = cp.name;        cout << "this name is "<< this->name << "\t" << cp.name << endl;    }    ~A() {        delete name;        name = NULL;    }private:    static int cnt;    char* name;};int A::cnt = 0;int main(){    A test1("nihao");    A test2(test1);    A test3 = test1;    test3 = test2;    return 0;}