c++ - 将对象传递给函数时，必须重载哪些运算符才能查看所有操作？

Question

我想写一段代码来显示将对象传递给函数时在对象上完成的所有复制/赋值/删除等操作。

我是这样写的:

#include <iostream>

class A {
    public:
        A(){std::cout<<"A()"<<std::endl;}
        void operator=(const A& a ){std::cout<<"A=A"<<std::endl;}
        A(const A& a){std::cout<<"A(A)"<<std::endl;}
        ~A(){std::cout<<"~A"<<std::endl;}
};

void pv(A a){std::cout<<"pv(A a)"<<std::endl;}
void pr(A& a){std::cout<<"pr(A& a)"<<std::endl;}
void pp(A* a){std::cout<<"pp(A* a)"<<std::endl;}
void pc(const A& a){std::cout<<"pc(const A& a)"<<std::endl;}

int main() {
    std::cout<<" -------- constr"<<std::endl;
    A a = A();
    std::cout<<" -------- copy constr"<<std::endl;
    A b = A(a);
    A c = a;
    std::cout<<" -------- assignment"<<std::endl;
    a = a;    
    a = b;
    std::cout<<" -------- pass by value"<<std::endl;
    pv(a);
    std::cout<<" -------- pass by reference"<<std::endl;
    pr(a);
    std::cout<<" -------- pass by pointer"<<std::endl;
    pp(&a);
    std::cout<<" -------- pass by const reference"<<std::endl;
    pc(a);
    return 0;
}

我是不是忘记了什么？在比较传递对象的不同方式时，还有什么必须考虑的吗？

Answer 1

在 C++11 中，你应该添加右值引用:

A(A&&);
void operator=(A&& a );