multithreading - std::future exception on gcc experimental implementation of C++0x

Question

I'm experimenting with C++0x threading, partially implemented in gcc 4.5 and I've got a problem, which I can't understand. Let's have a look on this code

#include <future>
#include <iostream>

int main()
{
        std::cout << std::async([]() { return 10; }).get() << std::endl;
}

it's quite simple and should work, but it's not. It throws std::system_error

terminate called after throwing an instance of 'std::system_error' what(): Aborted

what() returns empty string, so there is no error information at all. More then that, it wasn't working on the online compiler, which uses gcc 4.5 as well, but now it works. You can see it here http://liveworkspace.org/code/f3003d62a758e047a880920c84f1241c but yesterday it was throwing the same exception (though, no changes has been made on the server). Do you know what is the issue?

Thanks.

Answer 1

Try linking with -lpthread. For some reason the thread library does compile without pthreads but crashes at runtime.