c++ - Program to create a number of threads based on user input not working (cin)? -

my apologies if question looks simple. i'm still learning threads. tried searching solution on here didn't find any.

i'm trying program create number of threads based on user input (ex: "cin >> 5" create 5 threads) says "i" in "threads mythreads[ ]" needs constant value. code below:

void exec(int n) {     cout << "thread " << n << endl; }   int main() {     int numthreads = 0;      // create threads     cin >> numthreads;     thread mythreads[numthreads]; // part says mythreads "must constant value"      (int = 0; < numthreads; i++)     {               mythreads[i] = thread(exec, i);     }      (int = 0; < numthreads; i++)     {         mythreads[i].join();     }      cout << "done!" << endl; } 

any ideas how section can fixed? i've tried few different ways haven't worked far. thank much.

there's no problem multithreading. problem static array using dynamic array.

try this:

thread* mythreads = new thread[numthreads]; 

more dynamic memory in c++: http://www.cplusplus.com/doc/tutorial/dynamic/

upd james adkison: not forget delete[] array avoid memory leaking.