Composition “owns-a”(C++)
Composition in C++ is defined as implementing complex objects using simpler or smaller ones.
Links
If A owns-a B, then generally:
- B does not have an independent existence for A
- If A dies, then B dies
- If A is copied, B is copied as well (deep copy)
How is "owns-a" implemented?
Typically, this is implemented in C++ via object fields (or unique_ptr fields).
A Linked List is a “owns-a” relationship.
class List {
struct Node;
Node* head = nullptr;
}Inheritance is tightly coupled whereas composition is loosely coupled.
https://www.digitalocean.com/community/tutorials/composition-vs-inheritance