使用标准库替代boost中的thread group

转载修改自 秋天的栗树:用std::thread替换实现boost::thread_group

• 使用unique_ptr替换了其中的auto_ptr(已不受支持)；
• 添加了<functional> 和<algorithm>两个头文件；

#include <list>
#include <mutex>
#include <thread>
#include <memory>
#include <algorithm>
#include <functional>
namespace std
{
    //兼容boost::thread_group
    //使用std::thread代替boost::thread,std::mutex代替boost::shared_mutex
    class thread_group
    {
    private:
        thread_group(thread_group const&);
        thread_group& operator=(thread_group const&);
    public:
        thread_group() {}
        ~thread_group()
        {
            for(auto it=threads.begin(),end=threads.end();    it!=end;++it)
            {
                delete *it;
            }
        }

        template<typename F>
        thread* create_thread(F threadfunc)
        {
            lock_guard<mutex> guard(m);
            unique_ptr<thread> new_thread(new thread(threadfunc));
            threads.push_back(new_thread.get());
            return new_thread.release();
        }

        void add_thread(thread* thrd)
        {
            if(thrd)
            {
                lock_guard<mutex> guard(m);
                threads.push_back(thrd);
            }
        }

        void remove_thread(thread* thrd)
        {
            lock_guard<mutex> guard(m);
            auto it=std::find(threads.begin(),threads.end(),thrd);
            if(it!=threads.end())
            {
                threads.erase(it);
            }
        }

        void join_all()
        {
            lock_guard<mutex> guard(m);
            for(auto it=threads.begin(),end=threads.end();it!=end;++it)
            {
                (*it)->join();

            }
        }

        size_t size() const
        {
            lock_guard<mutex> guard(m);
            return threads.size();
        }

    private:
        list<thread*> threads;
        mutable mutex m;
    };
}