Can you explain the principle of cooperative multitasking in operating systems?

The copy-on-write (COW) mechanism is not applicable to all data types and structures. It is usually used to optimize working with mutable objects that initially can share the same memory.

In iOS, COW is applied, for example, to Swift collections (Array, Dictionary, Set), where copying data is deferred until a modification occurs.

However, for data types that do not support COW or for classes with reference semantics, this principle does not work automatically. In such cases, copying occurs either by reference or as a full copy.

Thus, COW is an optimization selectively applied depending on the implementation of the specific data type.