如何深度复制boost :: shared_ptr后面的完整对象 <T> 进入shared_ptr指向新位置？

Question

如何复制boost::shared_ptr<T>后面的完整对象：是否有memcopy选项（只是创建内存克隆），或者我们将创建复制构造函数？

Answer 1

You need a copy constructor or an operator= that will perform the deep copy.

boost::shared_ptr cannot know your object's structure to do this for you. Neither can a "memory clone" operation.

Of course, this is only for objects, that need an explicitly defined copy constructor / operator= and the "trivial" ones make a shallow copy.

Answer 2

If you know the exact type of the object, then you should use a copy constructor or copy assignment operator.

If the objects is an instance of a class in an inheritance hierarchy, and you do not know the exact type of the object, then you should use a virtual clone function.

Answer 3

You should create a copy constructor and write something like:

ptr.reset(new T);
*ptr  = *(otherObject.ptr);

in order to deep copy the pointer.