C++ concurrent_queue

ConcurrentQueue

用C++11提供的多線程類實現一個線程安全的隊列：

#include <queue>
#include <mutex>
#include <condition_variable>
#include <utility>

template<typename T, typename Queue = std::queue<T>>
class ConcurrentQueue {
public:
    template<typename U>
    void push(U&& elem) {
        {
            std::lock_guard<std::mutex> guard(m_mutex);
            m_queue.push(std::forward<U>(elem));
        }
        m_cv.notify_one();
    }

    T pop() {
        std::unique_lock<std::mutex> lock(m_mutex);
        m_cv.wait(lock, [this] { return !m_queue.empty(); });
        auto elem = std::move(m_queue.front());
        m_queue.pop();
        return elem;
    }

private:
    std::mutex m_mutex;
    std::condition_variable m_cv;
    Queue m_queue;
};