33 std::lock_guard<std::mutex> lock(m_mutex);
34 return m_queue.size();
38 std::lock_guard<std::mutex> lock(m_mutex);
39 return m_queue.empty();
43 std::lock_guard<std::mutex> lock(m_mutex);
44 return m_queue.front();
47 void push(
const T& value) {
48 std::lock_guard<std::mutex> lock(m_mutex);
53 std::lock_guard<std::mutex> lock(m_mutex);
58 std::queue<T> m_queue;
59 mutable std::mutex m_mutex;