Conteúdo do Curso
C++ Smart Pointers
C++ Smart Pointers
Best Practices of Using Shared Pointers
Only use shared pointers when you can’t use unique
Unique pointers should always be your first consideration when allocating a dynamic object. Only revert to shared pointers if you can justify the need for sharing.
Initialize shared pointers at the point of declaration
To enhance code readability and maintainability, it’s recommended to initialize a shared pointer when you declare it. This practice ensures that the shared pointer points to a valid object from the start and reduces the chances of accessing a null or uninitialized pointer.
good.cpp
bad.cpp
Minimize the shared scope
While it's generally safe to use shared pointers, it's essential to exercise caution when sharing them. Strive to keep the scope of shared pointers as narrow as possible. This will ensure that they are released as soon as they are no longer needed.
Beware of circular references
Circular references occur when a group of shared pointers form a loop. Each shared pointer references the next one, and the last shared pointer in the loop goes back to the first one. This leads to a closed circle of references, where the reference count never goes to 0. Consider the following example:
main.cpp
Code Description
In the main function, we create three Node objects: node1, node2, and node3. To simulate a circular reference, we make node1 point to node2, node2 point to node3, and node3 point back to node1. This creates a circular chain of references. The problem here is that when the function ends, the destructors for the Node objects are not called. This is because the reference count for each Node object never reaches 0, due to the circular references. A good way to avoid circular references is to use weak pointers. We will learn about them in the next chapter.
In the code above, we have three Node objects, which represent connected elements in a linked list. Each Node has a next member, which is a shared pointer pointing to the next element in the linked list.
Tudo estava claro?
Conteúdo do Curso
C++ Smart Pointers
C++ Smart Pointers
Best Practices of Using Shared Pointers
Only use shared pointers when you can’t use unique
Unique pointers should always be your first consideration when allocating a dynamic object. Only revert to shared pointers if you can justify the need for sharing.
Initialize shared pointers at the point of declaration
To enhance code readability and maintainability, it’s recommended to initialize a shared pointer when you declare it. This practice ensures that the shared pointer points to a valid object from the start and reduces the chances of accessing a null or uninitialized pointer.
good.cpp
bad.cpp
Minimize the shared scope
While it's generally safe to use shared pointers, it's essential to exercise caution when sharing them. Strive to keep the scope of shared pointers as narrow as possible. This will ensure that they are released as soon as they are no longer needed.
Beware of circular references
Circular references occur when a group of shared pointers form a loop. Each shared pointer references the next one, and the last shared pointer in the loop goes back to the first one. This leads to a closed circle of references, where the reference count never goes to 0. Consider the following example:
main.cpp
Code Description
In the main function, we create three Node objects: node1, node2, and node3. To simulate a circular reference, we make node1 point to node2, node2 point to node3, and node3 point back to node1. This creates a circular chain of references. The problem here is that when the function ends, the destructors for the Node objects are not called. This is because the reference count for each Node object never reaches 0, due to the circular references. A good way to avoid circular references is to use weak pointers. We will learn about them in the next chapter.
In the code above, we have three Node objects, which represent connected elements in a linked list. Each Node has a next member, which is a shared pointer pointing to the next element in the linked list.
Tudo estava claro?
