How to use pthread on Qt Creator

Question

I want to execute a following code.

#include <iostream>
#include <thread>

void output() {
    std::cout << "Hello World" << std::endl;
}

int main()
{
    std::thread t(output);
    t.join();

    return 0;
}

I can't execute it.

Qt Creator outputs terminate called after throwing an instance of 'std::system_error' what(): Operation not permitted

However I can execute on the terminal using the option of -pthread. Could you tell me how to use the option of -pthread in Qt Creator?

My developing environment is Ubuntu(12.04), g++4.6.3, Qt Creator(2.4.1).

Thank you.

Answer 1

You also need to link against -pthread. If you use g++ main.cpp -std=c++0x -pthread you are doing all that in one step, so it works correctly. To make Qt do the correct things, add the following to your project file:

QMAKE_CXXFLAGS += -std=c++0x -pthread 
LIBS += -pthread

Answer 2

This works for me:

TEMPLATE = app
TARGET = 
DEPENDPATH += .
INCLUDEPATH += .

# Input
SOURCES += test.cpp

QMAKE_CXXFLAGS += -std=gnu++0x -pthread
QMAKE_CFLAGS += -std=gnu++0x -pthread

Your example compiles and executes correctly with the above .pro file on my system.

Try save your example as test.cpp, and the above as project.pro in same directory. Then type:

$ qmake
$ make
$ ./project
Hello World