<分区>
我正在尝试使用 STL 学习 C++，我注意到 deconstruct 调用比 construct 调用多，我想知道我是否错过任何东西。
代码如下:
#include <vector>
#include <iostream>
using namespace std;
class Person {
friend ostream &operator<<(ostream& os, const Person &p) {
os << p.name << endl;
return os;
}
string name;
public:
Person() {
cout << "created " << this->name << endl;
};
Person(string name):
name{name} {
cout << "created " << this->name << endl;
}
~Person() {
cout << "deconstructor " << this->name << endl;
}
bool operator<(const Person &rhs) const {
return this->name < rhs.name;
}
bool operator==(const Person &rhs) const {
return (this->name == rhs.name);
}
};
int main(int argc, char** argv) {
vector<Person> vec {{"test1"}, {"test2"}};
Person p {"test2"};
vector<Person>::iterator it = find(vec.begin(), vec.end(), p);
Person p2 {"test3"};
vec.insert(it, p2);
for (auto &p : vec) {
cout << p;
}
}
这是输出:
created test1
created test2
deconstructor test2
deconstructor test1
created test2
created test3
deconstructor test2
deconstructor test1
test1
test3
test2
deconstructor test3
deconstructor test2
deconstructor test2
deconstructor test3
deconstructor test1
test1 被解构了三次，但只创建了一次。
有什么解释吗？
谢谢。