C++ Patterns - Thread-safe Queue ​

#ifndef _THREADSAFE_QUEUE_H_
#define _THREADSAFE_QUEUE_H_

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

template <class T> class ThreadsafeQueue {
public:
  ThreadsafeQueue(void) : queue(), mutex(), condition() {}
  ~ThreadsafeQueue(void) {}

  void enqueue(T t) {
    std::lock_guard<std::mutex> lock(mutex);
    queue.push(t);
    condition.notify_one();
  }

  T dequeue(void) {
    std::unique_lock<std::mutex> lock(mutex);
    while (queue.empty()) {
      condition.wait(lock);
    }
    T val = queue.front();
    queue.pop();
    return val;
  }

  int empty() { return queue.empty(); }

private:
  std::queue<T>           queue;
  mutable std::mutex      mutex;
  std::condition_variable condition;
};

#endif // _THREADSAFE_QUEUE_H

#ifndef _THREADSAFE_QUEUE_H_
#define _THREADSAFE_QUEUE_H_

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

template <class T> class ThreadsafeQueue {
public:
  ThreadsafeQueue(void) : queue(), mutex(), condition() {}
  ~ThreadsafeQueue(void) {}

  void enqueue(T t) {
    std::lock_guard<std::mutex> lock(mutex);
    queue.push(t);
    condition.notify_one();
  }

  T dequeue(void) {
    std::unique_lock<std::mutex> lock(mutex);
    while (queue.empty()) {
      condition.wait(lock);
    }
    T val = queue.front();
    queue.pop();
    return val;
  }

  int empty() { return queue.empty(); }

private:
  std::queue<T>           queue;
  mutable std::mutex      mutex;
  std::condition_variable condition;
};

#endif // _THREADSAFE_QUEUE_H