queue-的常见操作

#include<iostream>#include <queue>#include <list>using namespace std;#if 0*   1.队列是一种容器适配器, 用于在FIFO上下文中进行操作, 其中元素从一段插入, 然后在另一端进行提取;*   2.队列实现为容器适配器, 使用特定容器类的封装对象作为其底层容器的类, 提供一些特定成员来访问其中的元素, 元素被推入特定容器的后面, 并且从容器的前面弹出;*   3.构造函数通常包括一下几种:*   1.explict queue(const container_type& ctnr)*   2.explict queue(container_type&& ctnr = container_type());*   3.template <class Alloc> explict queue(const Alloc& alloc);*   4.template <class Alloc> explict queue(const container_type& cntr, const Alloc& alloc);*   5.template <class Alloc> explict queue(container_type&& cntr, const Alloc &alloc);*   6.template <class Alloc> explict queue(const queue& X, const Alloc& alloc);*   7.template <class Alloc> explict queue(queue&& X, const Alloc& alloc);#endifint main(){    //construct object;    deque<int> mydeque(3, 33);    list<int> mylist(2, 11);    queue<int> first;    first.push(3);    queue<int> second(mydeque);    queue<int, list<int>> third;    queue<int, list<int>> fourth(mylist);    cout << "first.size: " << first.size() << endl;    cout << "second.size: " << second .size() << endl;    cout << "third size: " << third.size() << endl;    cout << "fourth.size: " << fourth.size() << endl;    //.back():用于返回当前队列的最后一个元素;    // reference& back();    // const_reference& back() const;    cout << "first.back: " << first.back() << endl;#if 1    //.front()用于返回第一个元素    //reference& front();    //const_reference& front() const;    first.front() += first.back();    cout << "first.front: " << first.front() << endl;    //.emplace(): template <class... args> void emplace(Args&&.. args)    //用于在队列尾部添加一个新的元素;    queue<string> myqueuestring;    myqueuestring.emplace("this is a freshman");    myqueuestring.emplace("this is a oldman");    cout << "myqueuestring constains: ";    while (!myqueuestring.empty())    {        cout << myqueuestring.front() << "   ";        myqueuestring.pop();    }    cout << endl;    //.push用于在一段放入元素;    //void push(const value_type& val);    //void push(value_type&& val);    myqueuestring.push("that is a no-name man");    //.size()用于返回队列里面元素的多少;    //.swap():用于交换两个队列的值;    queue<int> newfirst;    newfirst.push(1);    newfirst.push(2);    newfirst.push(3);    newfirst.push(4);    newfirst.push(5);    queue<int> newsecond;    newsecond.push(5);    newsecond.push(4);    newsecond.push(3);    newsecond.push(2);    newsecond.push(1);    cout << "newfirst contains: ";    while (!newfirst.empty())    {        cout << newfirst.front() << " ";        newfirst.pop();    }    cout << endl;    cout << "newsecond contains: ";    while (!newsecond.empty())    {        cout << newsecond.front() << " ";        newsecond.pop();    }    cout << endl;#endif}