c++ 判断list是否为空（empty）

#include <list>

#include <iostream>

using namespace std;

int main()

{

    list<int> numbers;

    cout << "Initially, numbers.empty(): " << numbers.empty() << '\n';

    numbers.push_back();

    numbers.push_back();

    cout << "After adding elements, numbers.empty(): " << numbers.empty() << '\n';

}