浅析C++智能指针和enable_shared_from_this机制

class ObjectPool:boost::noncopyable //为 class ObjectPool:public boost::enable_shared_from_this，
                boost::noncopyable
{/*...*/};

第二处修改：

//改变 shared_ptrget(const string& key) { /*...*/ shObject.reset(new Object(key),
                     boost::bind(&ObjectPool::deleteObject,this,_1)); /*...*/ } //为 shared_ptrget(const string& key) { /*...*/ shObject.reset(new Object(key),
                     boost::bind(&ObjectPool::deleteObject,shared_from_this(),_1)); /*...*/ }

完整代码：

#include class ObjectPool:public boost::enable_shared_from_this，
                boost::noncopyable
{ public: shared_ptrget(const string& key) { shared_ptrshObject; MutexLockGuard lock(mutex);
   weak_ptr& wkObject=object[key];
   shObject=wkObject.lock();//对象存在，提升成功并返回 if(!shObject){ /*对象不存在，提升失败，shOject重新指向新创建的
    Object对象，并绑定回调函数，让对象Oject需要析构时
    调用OjectPool对象的成员函数*/ shObject.reset(new Object(key),
                      boost::bind(&
          ObjectPool::deleteObject,shared_from_this(),
          _1));
      wkObject=shObject;
   } return shObject;
} private: void deleteObject(Object* obj) { /*回调函数，在对象需要析构时调用，从map中删除对象和对
应的key*/ if(obj){ MutexLockGuard lock(mutex);
     object.erase(obj->key());
    } delete obj;
} mutable MutexLock mutex; std::map<string,weak_ptr> object; /*map中不能使用shared_ptr，这会导致Oject对象永远不会被销
毁*/ };

小牛：不错不错，这下懂了 shared_ptr和 weak_ptr结合的用法了吧。