Using a vector of thread in another thread : error attempting to reference a deleted function

Question

I'm trying to send a vector to parameter of another thread's function :

void foo(){}
const int n = 24;
void Thread_Joiner(std::vector<thread>& t,int threadNumber)
{
    //some code
}
int main()
{
    std::vector<thread> threads(n, thread(foo));
    thread Control_thread1(Thread_Joiner, threads, 0);//error
    thread Control_thread2(Thread_Joiner, threads, 1);//error
    //...
}

The above code give this error :

: attempting to reference a deleted function

I checked the header file of std::thread It seems that copy constructor is deleted : thread(const thread&) = delete;

std::thread have a move constructor but I don't think in this case using move is helpfull because Control_thread1 and Control_thread2 use same vector !

If I use thread **threads;... instead of that vector It works fine but I don't want to use pointers .

What should I do ?!

David G · Accepted Answer · 2014-06-11 16:44:40Z

3

std::thread copies the arguments used for the bind. Use std::ref to contain it as a reference:

std::thread Control_thread1(Thread_Joiner, std::ref(threads), 0);
std::thread Control_thread2(Thread_Joiner, std::ref(threads), 1);

answered Jun 11, 2014 at 16:44

David G

97.6k41 gold badges173 silver badges258 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

David G Over a year ago

@xyz The constructor of your vector is also attempting to copy a thread(foo) object.

uchar Over a year ago

well that's the question how can I fix that ?! using vector<thread*> ?

David G Over a year ago

@xyz Yes, but it's preferable to use smart pointers: std::vector<std::shared_ptr<std::thread>> threads(n, std::make_shared<std::thread>(foo)). And if you're not intending to extend the vector past its declared size, use std::array<24, std::shared_ptr<std::thread>>

David G Over a year ago

@xyz Actually all you need is std::vector<std::thread> threads; for (auto& th : threads) th = std::thread(foo);.

David G Over a year ago

@xyz I know but it was wrong of me to suggest using shared_ptr when it works fine without. See this example.

Collectives™ on Stack Overflow

Using a vector of thread in another thread : error attempting to reference a deleted function

1 Answer 1

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related