Something

struct Runner {
        Runner ( BcastEval_Impl* b ) : m_b(b) {}
        void operator () () { m_b->run(); }
        BcastEval_Impl* m_b;
};

void BcastEval_Impl::start ()
{
        m_log << "start" << endl;
        m_thread = new thread(Runner(this));
        m_log << "start ended" << endl;
}

void BcastEval_Impl::run ()
{
// du bordel
}