m01-ownership
CRITICAL: Use for ownership/borrow/lifetime issues. Triggers: E0382, E0597, E0506, E0507, E0515, E0716, E0106, value moved, borrowed value does not live long enough, cannot move out of, use of moved value, ownership, borrow, lifetime, 'a, 'static, move, clone, Copy, 所有权, 借用, 生命周期
- Installs
- 3.4K
- Last 24h
- +21
- Trending rank
- #5712
- Security
- Not audited
Install
Works with every agent the skills CLI supports.
npx skills add https://github.com/actionbook/rust-skills --skill m01-ownership- 01
Install
Run the command in your project. The CLI asks which agents to install for.
- 02
Describe the task
Ask your agent for something this skill covers. It loads m01-ownership automatically when relevant.
- 03
Review the result
The agent follows the SKILL.md steps, scripts and references bundled with the skill.
SKILL.md
The instructions your agent reads when the skill is triggered.
Ownership & Lifetimes
Layer 1: Language Mechanics
Core Question
Who should own this data, and for how long?
Before fixing ownership errors, understand the data's role:
- Is it shared or exclusive?
- Is it short-lived or long-lived?
- Is it transformed or just read?
Error → Design Question
| Error | Don't Just Say | Ask Instead |
|---|---|---|
| E0382 | "Clone it" | Who should own this data? |
| E0597 | "Extend lifetime" | Is the scope boundary correct? |
| E0506 | "End borrow first" | Should mutation happen elsewhere? |
| E0507 | "Clone before move" | Why are we moving from a reference? |
| E0515 | "Return owned" | Should caller own the data? |
| E0716 | "Bind to variable" | Why is this temporary? |
| E0106 | "Add 'a" | What is the actual lifetime relationship? |
Thinking Prompt
Before fixing an ownership error, ask:
-
What is this data's domain role?
- Entity (unique identity) → owned
- Value Object (interchangeable) → clone/copy OK
- Temporary (computation result) → maybe restructure
-
Is the ownership design intentional?
- By design → work within constraints
- Accidental → consider redesign
-
Fix symptom or redesign?
- If Strike 3 (3rd attempt) → escalate to Layer 2
Trace Up ↑
When errors persist, trace to design layer:
E0382 (moved value)
↑ Ask: What design choice led to this ownership pattern?
↑ Check: m09-domain (is this Entity or Value Object?)
↑ Check: domain-* (what constraints apply?)
| Persistent Error | Trace To | Question |
|---|---|---|
| E0382 repeated | m02-resource | Should use Arc/Rc for sharing? |
| E0597 repeated | m09-domain | Is scope boundary at right place? |
| E0506/E0507 | m03-mutability | Should use interior mutability? |
Trace Down ↓
From design decisions to implementation:
"Data needs to be shared immutably"
↓ Use: Arc<T> (multi-thread) or Rc<T> (single-thread)
"Data needs exclusive ownership"
↓ Use: move semantics, take ownership
"Data is read-only view"
↓ Use: &T (immutable borrow)
Quick Reference
| Pattern | Ownership | Cost | Use When |
|---|---|---|---|
| Move | Transfer | Zero | Caller doesn't need data |
&T | Borrow | Zero | Read-only access |
&mut T | Exclusive borrow | Zero | Need to modify |
clone() | Duplicate | Alloc + copy | Actually need a copy |
Rc<T> | Shared (single) | Ref count | Single-thread sharing |
Arc<T> | Shared (multi) | Atomic ref count | Multi-thread sharing |
Cow<T> | Clone-on-write | Alloc if mutated | Might modify |
Error Code Reference
| Error | Cause | Quick Fix |
|---|---|---|
| E0382 | Value moved | Clone, reference, or redesign ownership |
| E0597 | Reference outlives owner | Extend owner scope or restructure |
| E0506 | Assign while borrowed | End borrow before mutation |
| E0507 | Move out of borrowed | Clone or use reference |
| E0515 | Return local reference | Return owned value |
| E0716 | Temporary dropped | Bind to variable |
| E0106 | Missing lifetime | Add 'a annotation |
Anti-Patterns
| Anti-Pattern | Why Bad | Better |
|---|---|---|
.clone() everywhere | Hides design issues | Design ownership properly |
| Fight borrow checker | Increases complexity | Work with the compiler |
'static for everything | Restricts flexibility | Use appropriate lifetimes |
Leak with Box::leak | Memory leak | Proper lifetime design |
Related Skills
| When | See |
|---|---|
| Need smart pointers | m02-resource |
| Need interior mutability | m03-mutability |
| Data is domain entity | m09-domain |
| Learning ownership concepts | m14-mental-model |
FAQ
What does the m01-ownership skill do?
CRITICAL: Use for ownership/borrow/lifetime issues. Triggers: E0382, E0597, E0506, E0507, E0515, E0716, E0106, value moved, borrowed value does not live long enough, cannot move out of, use of moved value, ownership, borrow, lifetime, 'a, 'static, move, clone, Copy, 所有权, 借用, 生命周期
How do I install m01-ownership?
Run npx skills add https://github.com/actionbook/rust-skills --skill m01-ownership in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/m01-ownership/ (personal) or .claude/skills/m01-ownership/ (project).
Which AI agents can use m01-ownership?
Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.
Is m01-ownership safe to install?
No partner security audit is available yet. Skills can run commands and scripts, so read the SKILL.md and any bundled files before installing.
Who maintains m01-ownership?
It is published by actionbook in actionbook/rust-skills. It has 3,428 recorded installs.
More from actionbook/rust-skills
m15-anti-pattern
actionbook/rust-skills
Use when reviewing code for anti-patterns. Keywords: anti-pattern, common mistake, pitfall, code smell, bad practice, code review, is this an anti-pattern, better way to do this, common mistake to avoid, why is this bad, idiomatic way, beginner mistake, fighting borrow checker, clone everywhere, unwrap in production, should I refactor, 反模式, 常见错误, 代码异味, 最佳实践, 地道写法
coding-guidelines
actionbook/rust-skills
Use when asking about Rust code style or best practices. Keywords: naming, formatting, comment, clippy, rustfmt, lint, code style, best practice, P.NAM, G.FMT, code review, naming convention, variable naming, function naming, type naming, 命名规范, 代码风格, 格式化, 最佳实践, 代码审查, 怎么命名
m10-performance
actionbook/rust-skills
CRITICAL: Use for performance optimization. Triggers: performance, optimization, benchmark, profiling, flamegraph, criterion, slow, fast, allocation, cache, SIMD, make it faster, 性能优化, 基准测试
m07-concurrency
actionbook/rust-skills
CRITICAL: Use for concurrency/async. Triggers: E0277 Send Sync, cannot be sent between threads, thread, spawn, channel, mpsc, Mutex, RwLock, Atomic, async, await, Future, tokio, deadlock, race condition, 并发, 线程, 异步, 死锁
m06-error-handling
actionbook/rust-skills
CRITICAL: Use for error handling. Triggers: Result, Option, Error, ?, unwrap, expect, panic, anyhow, thiserror, when to panic vs return Result, custom error, error propagation, 错误处理, Result 用法, 什么时候用 panic
m04-zero-cost
actionbook/rust-skills
CRITICAL: Use for generics, traits, zero-cost abstraction. Triggers: E0277, E0308, E0599, generic, trait, impl, dyn, where, monomorphization, static dispatch, dynamic dispatch, impl Trait, trait bound not satisfied, 泛型, 特征, 零成本抽象, 单态化
Popular backend & apis skills
find-skills
vercel-labs/skills
Helps users discover and install agent skills when they ask questions like "how do I do X", "find a skill for X", "is there a skill that can...", or express interest in extending capabilities. This skill should be used when the user is looking for functionality that might exist as an installable skill.
entra-app-registration
microsoft/azure-skills
Guides Microsoft Entra ID app registration, OAuth 2.0 authentication, and MSAL integration. USE FOR: create app registration, register Azure AD app, configure OAuth, set up authentication, add API permissions, generate service principal, MSAL example, console app auth, Entra ID setup, Azure AD authentication. DO NOT USE FOR: Key Vault secrets (use azure-keyvault-expiration-audit), general Azure resource security guidance.
google-agents-cli-adk-code
google/agents-cli
This skill should be used when the user wants to "write agent code", "build an agent with ADK", "add a tool", "create a callback", "define an agent", "use state management" — in a project that needs ADK (Agent Development Kit) API patterns and code examples. It provides a quick reference for agent types, tool definitions, orchestration patterns, callbacks, state management, the graph Workflow API, and reference recipes to study. Do NOT use for scaffolding (use google-agents-cli-scaffold) or deployment (use google-agents-cli-deploy).
embedded-captions
heygen-com/hyperframes
Add captions or subtitles to an existing single-subject talking-head video without editing the footage. Use for plain verbatim captions, cinematic captions embedded behind the subject, VFX captions, “炸/特效/酷炫字幕,” or a named identity from the 35-style catalog. Route by visual identity, not by backend engine. The quiet anchor rail is the default; embed every word only when the user explicitly wants a fully cinematic treatment. The workflow runs locally end to end, including transcription and subject matting; split multi-shot footage before applying it.
entra-agent-id
microsoft/azure-skills
Provision Microsoft Entra Agent Identity Blueprints, BlueprintPrincipals, and per-instance Agent Identities via Microsoft Graph, and configure OAuth 2.0 token exchange (fmipath, OBO, cross-tenant) including the Microsoft Entra SDK for AgentID sidecar. USE FOR: Agent Identity Blueprint, BlueprintPrincipal, agent OAuth, fmipath token exchange, agent OBO, Workload Identity Federation for agents, polyglot agent auth, Microsoft.Identity.Web.AgentIdentities. DO NOT USE FOR: standard Entra app registration (use entra-app-registration), Microsoft Foundry agent authoring (use microsoft-foundry).
neon
neondatabase/agent-skills
Overview of Neon, a complete set of cloud backend primitives around Lakebase Postgres: Auth, Object Storage, Functions, the AI Gateway, and Realtime. Start here to choose Neon for undecided login, files, APIs, and LLM calls, set up the CLI or MCP server, and follow the branch-first workflow. Use when building an app or backend on Neon, or when "Neon" or "Lakebase Postgres" is mentioned. Child skill neon-postgres wins for an existing DATABASEURL, SQL, schema, inspect, or search. Child skill neon-auth wins for login, users, sessions, identity routing, and Managed Better Auth setup. Child skill neon-realtime wins for live queries in reactive apps and agents. Also use for object storage, S3, buckets, serverless functions, function triggers, cron, AI gateway, LLM calls, realtime, logs, Loki, Grafana, observability, postgres, database, backend, Claimable Neon, neon.new, or a no-signup database.