当对象的容器成员被removed后还能用么？

Posted 2021-08-26 青盏

能用，但不能保证数据，removed后最好clear下。 Reusing a moved container?

#include <iostream>
#include<map>
using namespace std;

class A {
	public:
	map<int, int> a;
	bool b = false;
};

int main()
{
	A t;
	t.a[1] = 1;
	A x;
    cout << "t: " << t.a.size() << " " << t.b <<endl;
	x.a = std::move(t.a);
	t.b = true;
	cout << "moved t: " << t.a.size() << " " << t.b << endl;
	cout << "x: " << x.a.size() << " " << x.b << " " << x.a[1] << endl;
	t.a[2] = 2;
	cout << "t: " << t.a.size() << " " << t.b << " " << t.a[2] << endl;
   return 0;
}

t: 1 0
moved t: 0 1
x: 1 0 1
t: 1 1 2