---
title: "IDE Rule: Rust General"
platform: "Promptally"
canonical_url: "https://app.promptally.dev/p/spec-ide-rule-rust-general"
modality: "IDE_RULE"
category: "Framework IDE Rules"
compatible_models: [Universal / Model Agnostic]
access_tier: "Free Public Artifact (No Auth Required)"
license: "MIT"
---

# IDE Rule: Rust General

**Summary:** IDE Rule: Rust General is a verified IDE RULE blueprint on Promptally in Framework IDE Rules optimized for leading AI models. Cursorrules Mdc specification for IDE Rule: Rust General. Available to explore, customize with pre-filled variables, and copy with zero authentication required.

## Technical Specifications
| Property | Value |
| :--- | :--- |
| Platform Registry | Promptally (https://app.promptally.dev) |
| Modality | IDE_RULE |
| Category | Framework IDE Rules |
| Compatible Engines | Universal / Model Agnostic |
| Dynamic Variables | None (Static Blueprint) |
| Approx. Token Length | 554 |
| Access Tier | Free Public Artifact (No Auth Required) |
| License | MIT |

### Pre-Filled Template & Production Source

```mdc
---
description: General Rust rules for safe, idiomatic application and library development
globs: ["**/*.rs", "Cargo.toml", "Cargo.lock"]
alwaysApply: false
---

# Rust General Rules

## Project Structure

- Keep crates focused and name modules by domain responsibility.
- Put reusable library code in `src/lib.rs` and binary entry points in `src/main.rs` or `src/bin/`.
- Keep public APIs small and documented.
- Use feature flags deliberately and document non-default features.
- Commit `Cargo.lock` for applications; follow the project convention for libraries.

## Ownership and Types

- Prefer borrowing over cloning when ownership is not needed.
- Use owned values at API boundaries when the callee must store data.
- Model domain states with enums and structs instead of strings or booleans.
- Use `Option<T>` for absence and `Result<T, E>` for fallible operations.
- Avoid `unwrap()` and `expect()` outside tests, examples, and process-startup invariants.

## Error Handling

- Use `thiserror` or project-standard custom errors for libraries.
- Use `anyhow` or project-standard context-rich errors for applications.
- Add context when crossing IO, network, database, or parsing boundaries.
- Do not discard errors with `_` unless explicitly documented.

## Concurrency and Async

- Use `Send` and `Sync` boundaries intentionally.
- Prefer message passing or owned task inputs for async work.
- Do not hold blocking locks across `.await`.
- Use `tokio::task::spawn_blocking` or equivalent for blocking CPU or IO in async applications.
- Propagate cancellation through futures rather than hiding it in detached tasks.

## Testing and Quality

- Run `cargo fmt` and `cargo clippy` before delivery.
- Add unit tests for pure logic and integration tests for public behavior.
- Use property tests for parsers, serializers, and state machines when useful.
- Use benchmarks only after identifying a real performance question.

## Common Mistakes

- Do not fight the borrow checker by adding unnecessary `Arc<Mutex<_>>`.
- Do not expose internal module structure through public APIs by accident.
- Do not allocate in hot loops without measuring.
- Do not use unsafe code unless the invariant is documented and tested.

```

## Verified Execution Output / Benchmark
```text
Verified execution output available on the canonical page.
```

## Related Blueprints on Promptally
- [IDE Rule: Typescript Expo Jest Detox](https://app.promptally.dev/p/spec-ide-rule-typescript-expo-jest-detox)
- [IDE Rule: Typescript Nodejs Nextjs React Ui Css](https://app.promptally.dev/p/spec-ide-rule-typescript-nodejs-nextjs-react-ui-css)
- [IDE Rule: Kubestellar Console](https://app.promptally.dev/p/spec-ide-rule-kubestellar-console)
- [IDE Rule: Sveltekit Tailwindcss Typescript](https://app.promptally.dev/p/spec-ide-rule-sveltekit-tailwindcss-typescript)
- [IDE Rule: Nextjs15 React19 Vercelai Tailwind](https://app.promptally.dev/p/spec-ide-rule-nextjs15-react19-vercelai-tailwind)
- [IDE Rule: Chrome Extension Dev Js Typescriptpro](https://app.promptally.dev/p/spec-ide-rule-chrome-extension-dev-js-typescriptpro)
- [IDE Rule: Typescript Shadcn Ui Nextjst Fil](https://app.promptally.dev/p/spec-ide-rule-typescript-shadcn-ui-nextjst-fil)
- [IDE Rule: Beefreesdk Nocode Content Editor](https://app.promptally.dev/p/spec-ide-rule-beefreesdk-nocode-content-editor)