m02-resource

SKILL.md

Smart pointer and resource ownership patterns for Rust heap allocation and reference counting.

Guides ownership decisions through a three-step model: single vs. shared ownership, single-threaded vs. multi-threaded context, and presence of reference cycles

Covers six core types (Box, Rc, Arc, Weak, Cell, RefCell) with a decision flowchart and quick reference table for choosing the right pattern

Includes common errors and anti-patterns with fixes, such as using Weak to break cycles, avoiding unnecessary Arc overhead, and preventing RefCell panics

Traces design questions upward to concurrency and mutability concerns, and downward to concrete implementation choices

Resource Management

Layer 1: Language Mechanics

Core Question

What ownership pattern does this resource need?

Before choosing a smart pointer, understand:

Is ownership single or shared?

Is access single-threaded or multi-threaded?

Are there potential cycles?

Error → Design Question