Cyclic References
In this lesson, we'll examine how the use of shared pointers can create a reference cycle and why this could be harmful.
We'll cover the following
We get cyclic references of std::shared_ptr if they refer to each other.
The issue #
If we have a cyclic reference of std::shared_ptr, the reference counter will never become 0. We can break this cycle if by embedding an std::weak_ptr in the cycle. std::weak_ptr does not modify the reference counter.
Theoretically, we can use a raw pointer to break the cycle of
std::shared_ptr's, but a raw pointer has two disadvantages. First, they don’t have a well-defined interface. Second, they don’t support an interface that can create anstd::shared_ptrout of it.