Version: 1.1.0

Self-referential structs

A struct cannot contain a field of its own type directly, because the compiler needs a finite size. Pointers are how you build lists, trees, and graphs.

Essentials

• Store UnsafePointer[Node] or an index, not Node itself.
• Allocate each node with the allocator you intend to free.
• Destruction must walk the structure once so nothing is freed twice.
• Indexes into one array are often safer than a web of raw pointers.

Example

struct Node[T: Movable]:
    var value: T
    var next: UnsafePointer[Self]

Keep in mind

Prefer an existing collection until a custom linked structure is actually required. Pointer lifetime is your responsibility.