A bug. Segmentation fault with g++ 4.7.2, boost 1.54.0

bugged.cpp

#include <iostream>
#include <thread>
#include <mutex>
#include <condition_variable>
#include <chrono>
#include <boost/signals2.hpp>

class A
{
public:

    static A& Instance()
    {
        static A a;
        return a;
    }

public:

    boost::signals2::connection Connect(const std::function<void ()>& func) { return signal.connect(func); }
    void Test() { signal(); }

private:

    boost::signals2::signal<void ()> signal;

};

class B
{
public:

    void Run()
    {
        int c = 0;
        A::Instance().Connect([&](){ c++; });

        std::mutex mutex;
        std::condition_variable cv;
        std::thread thread(
            [&]()
            {
                std::unique_lock<std::mutex> lock(mutex);
                cv.wait(lock);
            });

        std::this_thread::sleep_for(std::chrono::milliseconds(100));
        cv.notify_one();
        thread.join();
    }

};

class C
{
public:

    void Run()
    {
        A::Instance().Connect(
            [&]()
            {
                std::cout << "Hello!" << std::endl;
            });
        A::Instance().Test();
    }

};

int main()
{
    B().Run();
    C().Run();
    return 0;
}