具体构造代码如下：

       regIOobject(const IOobject& io)                                                                                      

       :                                                                                                                                   

         IOobject(io),             //调用IOobject的复制构造函数，                                                

         registered_(false),   //默认设置registered_成员变量为false                          

         registries_(false),   //默认设置registries_成员变量为false                                           

         lastModified_(0),   //默认上次修改时间为0                                                               

         updated_(false),    //默认updated_为false                                                                   

         isPtr_(NULL)      //默认输入流指针为空                                                                 

      {                                                                                                                                  

              if (registerObject())          //调用已经构造好的基类Ioobject的成员函数registObject()     

              {                                                                                                                           

                     chekIn();               //调用db_.checkIn(*this)                                                       

              }   

       }                                                                                                                        

  这里实际上是看IOobject的registerObject_成员变量是否为true（默认情况下是true），如果是则将这个IOobject注册到对象注册器中（一般是runTime或mesh）。