How struct is deallocated

In Swift, the deallocation of a struct is closely tied to its memory management and storage principles. Structs in Swift use inline storage, meaning all of their stored properties are laid out inline in their container. This is different from classes, which use out-of-line storage and reference semantics.

When a struct is deallocated, the memory allocated for its stored properties is freed. This process is straightforward because structs are value types and their memory is managed inline. Here are some key points from the session "Explore Swift performance" at WWDC 2024:

1. Inline Storage: Structs use inline storage, meaning their stored properties are laid out inline in their container. This makes deallocation straightforward as the memory is directly managed within the container (Explore Swift performance).

2. Memory Allocation and Deallocation: Memory for structs is typically allocated on the stack, which is very cheap and efficient. When the function scope ends, the stack memory is automatically deallocated (Explore Swift performance).

3. Copying and Retaining: When copying a struct, all of its stored properties are recursively copied. This can lead to performance considerations, especially for large structs or those containing references to other objects (Explore Swift performance).

4. Dynamic Layout: For structs with dynamically sized properties, the layout is determined at runtime. This can affect how memory is allocated and deallocated, but the principles of inline storage still apply (Explore Swift performance).

For more detailed information, you can refer to the session "Explore Swift performance" from WWDC 2024, particularly the chapters on memory allocation and value copying.