[C/C++标准库]_[初级]_[优先队列priority_queue的使用]

std::priority_queue

场景:

1. 对于一个任务队列，任务的优先级由任务的priority属性指明，这时候就需要优先级越高的先执行。而queue并没有排序功能，这时priority_queue是比较好的选择.

2 对于异步的task也是一样，在不断添加新的task时,当然希望优先级越高的先执行.

解析:

1. 如果需要把优先级最高的先pop,那么comp比较时需要返回false.

代码:

//1.Elements are popped from the "back" of the specific container, 
//which is known as the top of the priority queue.
//2.shall return true if a is considered to go before b 
// in the strict weak ordering the function defines
#include 
#include 
#include 
#include 
using namespace std;

class Task
{
public:
	Task(int priority):priority_(priority)
	{

	}
	~Task(){}

	int priority_;
	void DoWork()
	{
		cout << "DoWork: " << (int)this << " priority: " << priority_ << endl;
	}
};


class PriorityCompare
{
public:
	bool operator()(Task* t1,Task* t2)
	{
		return t1->