rust-basics-types

A set of Rust coding rules covering error handling, generics, traits, and asynchronous programming. Rust is a systems programming language that checks memory and thread safety while compiling.

In plain words
What is it for?
Use it when writing or reviewing Rust code that parses input, returns errors, uses generic traits, or performs asynchronous work.
Why use it?
It gives consistent guidance for handling failures, reusable code, and background operations in Rust. This helps avoid common mistakes in code that must satisfy Rust’s compiler checks.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/wangqiqi/cursor-ai-rules/rust-basics-types
Clone the repo
git clone --depth 1 https://github.com/wangqiqi/cursor-ai-rules

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 419 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00419
Opus 5 $0.00000 $0.00210
Sonnet 5 $0.00000 $0.00084
Haiku 4.5 $0.00000 $0.00042

Measured 3d ago against content hash e7d488477cdc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

rust-basics-types scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/tech/rust-basics-types.mdc · 68 lines

What it actually says

Rust 类型系统 (Types)

本规则由 @rust-basics 引用

错误处理

#[derive(Debug)]
pub enum Error {
    Io(std::io::Error),
    Validation(String),
    NotFound(String),
}

impl std::error::Error for Error {}
impl From<std::io::Error> for Error { fn from(err: std::io::Error) -> Self { Error::Io(err) } }

pub type Result<T> = std::result::Result<T, Error>;

fn process_user_data(user_id: &str) -> Result<User> {
    let id: u64 = user_id.parse()?;
    let user = find_user_by_id(id).ok_or_else(|| Error::NotFound(format!("User {} not found", id)))?;
    Ok(user)
}

泛型与特征

pub trait Repository<T> {
    fn save(&self, item: &T) -> Result<()>;
    fn find_by_id(&self, id: u64) -> Result<Option<T>>;
}

impl<T: Clone + Validatable> Repository<T> for InMemoryRepository<T> { ... }

异步编程

#[async_trait::async_trait]
pub trait AsyncRepository<T>: Send + Sync {
    async fn save(&self, item: &T) -> Result<()>;
    async fn find_by_id(&self, id: u64) -> Result<Option<T>>;
}

pub struct SharedCounter {
    count: Mutex<i64>,
}

原则

  • MUST 使用 Result 和 ? 操作符
  • MUST 实现 std::error::Error
  • MUST 用 async_trait 定义异步特征

引用: @rust-basics

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 68 lines · 0 tokens per session scan A e7d488477cdc

Subscribe to this mod's changes

rust-basics-types is a cursor rule published in the GitHub repository wangqiqi/cursor-ai-rules (15 stars, last pushed 3mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 419 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.