rust

name	rust
description	Rust ownership model, async programming with Tokio, web frameworks (Axum/Actix), error handling, and systems programming patterns
layer	domain
category	backend
triggers	["rust","cargo","tokio","axum","actix","ownership","borrow checker","rust web"]
inputs	["Rust application requirements","Performance-critical system needs","Web service specifications"]
outputs	["Idiomatic Rust implementations","Async patterns with Tokio","Web framework configurations"]
linksTo	["microservices","postgresql","redis","websockets","message-queues"]
linkedFrom	["error-handling","testing"]
preferredNextSkills	["postgresql","redis","microservices"]
fallbackSkills	["golang","nodejs"]
riskLevel	low
memoryReadPolicy	selective
memoryWritePolicy	none
sideEffects	[]

Rust Domain Skill

Purpose

Provide expert-level guidance on Rust development, including the ownership system, async programming with Tokio, web framework patterns (Axum, Actix), error handling with thiserror/anyhow, and production-grade systems programming.

Key Patterns

1. Ownership and Borrowing

// Ownership rules:
// 1. Each value has exactly one owner
// 2. When the owner goes out of scope, the value is dropped
// 3. You can have EITHER one mutable reference OR any number of immutable references

// Prefer borrowing over cloning
fn process_name(name: &str) -> String {
    // Takes a reference -- no ownership transfer
    name.to_uppercase()
}

// Use lifetimes when the compiler needs help
struct Config<'a> {
    database_url: &'a str,
    app_name: &'a str,
}

impl<'a> Config<'a> {
    fn connection_string(&self) -> String {
        format!("{}?app={}", self.database_url, self.app_name)
    }
}

// Interior mutability for shared mutable state
use std::sync::{Arc, RwLock};

#[derive(Clone)]
struct AppState {
    cache: Arc<RwLock<HashMap<String, CachedItem>>>,
    db: Arc<Pool<Postgres>>,
}

impl  {
     (&, key: &)  <CachedItem> {
        .cache.().().(key).()
    }

     (&, key: , item: CachedItem) {
        .cache.().().(key, item);
    }
}