[Boost-users] How to access each elements of a thread group separately

Hi I'm using several threads to do some parallel work. But I need to stop them separatly through the interrupt method. In order to store all these threads, I thought that I would use the thread_group class since I cannot use the vector class. But it looks like I cannot acces an element of a thread group (to interrupt it separately for example). Is there anyway of doing this that I'm not aware of ? Thanks in adavnace for the help. Johan Mazel