C++拷贝构造函数和移动构造函数

#include<iostream>
#include<string>
using namespace std;
class Animal{
public:
Animal();
Animal(Animal &&animal)noexcept;//移动构造函数应该标记为不抛出异常
Animal(const Animal& animal);
Animal& operator=(Animal animal);//形参不设为引用，在赋值时回调用拷贝构造函数或者移动构造函数，左值拷贝，右值移动
private:
string name;
int weight;
};
Animal::Animal(){
name="";
weight=0;
}
Animal::Animal(const Animal& animal){
name=animal.name;
weight=animal.weight;
cout<<"Animal::Animal(Animal& animal)"<<endl;
}

Animal::Animal(Animal&& animal)noexcept{//noexcept说明不会抛出异常，必须和函数原型一致
name=animal.name;
weight=animal.weight;
cout<<"Animal::Animal(Animal&& animal)"<<endl;
}
Animal& Animal::operator=(Animal animal){
if(this!=&animal){
name=animal.name;
weight=animal.weight;
}
cout<<"Animal::operator=(Animal animal)"<<endl;
return *this;

}
int main(){
Animal bird1;
Animal bird2;
cout<<"左值"<<endl;
bird1=bird2;//左值
cout<<"右值"<<endl;
bird1=move(bird2);//右值
}