在Closuer join（）线程C ++之前更新joinable（）

Question

How to manage thread like this:

thread th(foo);

while(th.joinable())
{
  // thread foo is active;
  // some printing from foo function for example
}

th.join();

This while is infinite because th.joinable() is always true and not updating. What reason and how to solve this problem?

Answer 1

As Joachim pointed out, joinable() is true as long the thread is not already joined (or default constructed).

As I understand your requirements (from your comments), you may just call th.join() without the while-loop. This blocks until foo is finished.