A multi-threaded Producer Consumer with C++11

I am trying to learn concurrent programming in C++11. I tried to write code for a classic producer consumer concurrency problem. Would you please review and make any comments about it? #include <iostream> #include <thread> #include <deque> #include <mutex> #include <chrono> #include <condition_variable> using std::deque; std::mutex mu,cout_mu; std::condition_variable cond; class Buffer { public: v