C++(20)：自动join的jthread

C++20增加了jthread类，该类的对象可以在析构时自动调用join：

#include 
#include 
#include 
using namespace std;

unsigned long getTimestamp()
{
	return chrono::system_clock::now().time_since_epoch().count()/chrono::system_clock::period::den;
}

void func()
{
    for(int i = 0; i < 5; ++i) {
        std::cout << "Thread 1 executing:" << getTimestamp() <

运行程序输出：

begin:1694759618
Thread 1 executing:1694759618
Thread 1 executing:1694759619
Thread 1 executing:1694759620
Thread 1 executing:1694759621
Thread 1