Sharing different member values of the same object
Let's imagine we are maintaining a shared pointer to some complex, composed, and dynamically allocated object. Then, we want to start a new thread that does some time-consuming work on a member of this complex object. If we want to release this shared pointer now, the object will be deleted while the other thread is still accessing it. If we don't want to give the thread object the pointer to the whole complex object because that would mess with our nice interface, or for other reasons, does this mean that we have to do manual memory management now?
No. It is possible to use shared pointers that on one hand, point to a member of a large shared object, while on the other hand, perform automatic memory management for the entire initial object.
In this example, we will create such a scenario (without threads to keep it simple) in order to get a feeling for this handy feature of shared_ptr.
How to do it...
We are going to define a structure that...
