Problem with std :: thread from C ++ 11

Question

I have some problems trying to compile a multi-threaded program from the standard template library. It returns me an obscure error when I try to compile the following program:

#include <iostream> #include <thread> void foo() { std::cout << "Thread 1\n"; } int main(int argc, char** argv) { std::thread tr(foo); std::cout << "Main thread\n"; tr.join(); return 0; } 

I do not understand the error:

 /tmp/ccE8EtL1.o : In the function « std::thread::thread<void (&)()>(void (&)()) » : file.cpp:(.text._ZNSt6threadC2IRFvvEJEEEOT_DpOT0_[_ZNSt6threadC5IRFvvEJEEEOT_DpOT0_]+0x21) : undefined reference to « pthread_create » collect2: error : ld has return 1 execution status code 

I will compile it with

g ++ -std = C ++ 14 file.cpp -o test -Wall

Can anybody help me?

Answer 1

Pass -pthread compiler. This flag combines what is needed to compile and link the pthread library ( -lpthread not always enough) . See this question .