C++ Queue 中的 front函数

value_type& front();
const value_type& front() const;

#include <iostream>
#include <queue>
int main()
{
	std::queue<int> newqueue;
	newqueue.push(24);
	newqueue.push(80);
	newqueue.front () +=20;
	std::cout <<"newqueue.front() is modified to " << newqueue.front();
	return 0;
}

#include <iostream>
#include <queue>
using namespace std;
int main()
{
	queue<int> newqueue;
	newqueue.push(11);
	newqueue.push(22);
	newqueue.push(33);
	cout << newqueue.front();
	return 0;
}