C++示例11 std :: chrono :: duration

Question

我寫了一個示例函數來了解std::chrono::duration最近作爲C++ 11標準的一部分引入的行爲。

void exampleForDuration() 
{ 
    seconds Sec(minutes(1)); 

    cout<<"1 second is "<<duration_cast<nanoseconds>(seconds(1)).count()<<" nanoseconds"<<endl; 
    cout<<"1 minute is "<<Sec.count()<<" seconds"<<endl; 
    cout<<"1 second is "<<duration_cast<duration<int,centi>>(seconds(1)).count()<<" centiseconds"<<endl; 
    cout<<"100 second is "<<duration_cast<minutes>(seconds(100)).count()<<" minute."<<endl; 
    cout<<"Waiting for 10 seconds..."; 
    auto start=system_clock::now(); 
    this_thread::sleep_for(seconds(10)); 
    cout<<"Done."<<endl; 
    auto end=system_clock::now(); 
    auto waitedFor=end-start; 
    cout<<"Waited for "<<duration_cast<seconds>(waitedFor).count()<<" seconds"<<endl; 
    printCurrentDateTime(); 
} 

輸出：

1 second is 1000000000 nanoseconds 
1 minute is 60 seconds 
1 second is 100 centiseconds 
100 second is 1 minute.    -------> 1) 
Waiting for 10 seconds...Done.   -------> 2) 
Waited for 10 seconds 

當我跑的上述功能，該程序等待出奇10秒鐘打印1之後），而不是打印2之後）。我打算在打印完成後等待程序等待10秒...然後等待，然後打印「完成」。但它打印「100秒是1分鐘」。然後等待10秒鐘，然後輸出其餘部分。

Answer 1

是否正常工作，如果你改變

cout<<"Waiting for 10 seconds..."; 

到

cout<<"Waiting for 10 seconds..." << endl; 

這可能是因爲其不沖水，所以它不打印行了。