单生产者多消费者C++实现

并非原创，但原创文档链接丢失。。

请实现一个简单的文本文件处理程序，要求一个生产者线程负责读入数据，另一个消费者线程池负责处理数据

#include <iostream>
#include <mutex>
#include <queue>
#include <condition_variable>
#include <thread>
#include <functional>
using namespace std;

class LockQue {
public:
	void push_back(const string& line) {
		{
			std::unique_lock<std::mutex> lock(_mutex);
			_q.push(line);
		}
		_push_cv.notify_one();
	}

	string pop_back() {
		{
			std::unique_lock<std::mutex> lock(_mutex);
			_push_cv.wait(lock, [this]() {
				return !_q.empty();
			});
			auto r = _q.front();
			_q.pop();
			return r;
		}
	}

	size_t size() const {
		return _q.size();
	}

private:
	std::mutex _mutex;
	std::queue<string> _q;
	std::condition_variable _push_cv;
};

class ThreadPool {
public:
	ThreadPool(size_t numThreads) : stop(false) {
		for (size_t i = 0; i < numThreads; ++i) {
			threads.emplace_back([this] {
				while (true) {
					std::function<void()> task;
					{
						std::unique_lock<std::mutex> lock(this->queueMutex);
						this->condition.wait(lock, [this] { return this->stop || !this->tasks.empty(); });
						if (this->stop && this->tasks.empty()) {
							return;
						}
						task = std::move(this->tasks.front());
						this->tasks.pop();
					}
					task();
				}
			});
		}
	}

	~ThreadPool() {
		{
			std::unique_lock<std::mutex> lock(queueMutex);
			stop = true;
		}
		condition.notify_all();
		for (std::thread& thread : threads) {
			thread.join();
		}
	}

	template<class F>
	void enqueue(F&& f) {
		{
			std::unique_lock<std::mutex> lock(queueMutex);
			tasks.emplace(std::forward<F>(f));
		}
		condition.notify_one();
	}

private:
	std::vector<std::thread> threads;
	std::queue<std::function<void()>> tasks;
	std::mutex queueMutex;
	std::condition_variable condition;
	bool stop;
};

int main() {
	ThreadPool pool(4);

	LockQue q;
	thread input_thread([&]() {
		string s;
		while (cin >> s) {
			q.push_back(s);
			printf("q size:%lu\n", q.size());
		}
	});
	thread out_thread([&]() {
		while (true) {
			string s = q.pop_back();
			pool.enqueue([s] {
				cout << s << endl;
			});
		}
	});
	input_thread.join();
	return 0;
}