Undefined reference to pthread CLion

Question

I'm trying to run this simple thread c++ program in CLion

#include <iostream>
#include <thread>

using namespace std;


//Start of the thread t1
 void hello() {
     cout << "Hello,concurrent world!" << endl; }



 int main() {
     thread t1(hello);     // spawn new thread that calls hello()

     cout << "Concurrency has started!" << endl;
     t1.join();            

     cout << "Concurrency completed!";

     return 0;
   }

My problem is that there's an error of undefined reference to pthread, and I don't undestand what I'm doing wrong... please notice that I'm doing this on CLion.

Answer 1

In CLion, to compile with flag -pthread you should add the following line to CMakeLists.txt (I've tested and it works):

SET(CMAKE_CXX_FLAGS -pthread)

Answer 2

In CMake first find the package:

find_package(Threads REQUIRED)

Then link against it:

target_link_libraries(${PROJECT_NAME} Threads::Threads)

Now the build will succeed the linking step.