Rust Development Skill

This skill enforces structured, guideline-driven Rust development. It ensures all Rust code strictly follows the appropriate Microsoft-style rules, documentation formats, and quality constraints.

Mandatory Workflow

This skill MUST be invoked for ANY Rust action, including:

• Creating new .rs files (even minimal examples like Hello World)
• Modifying existing .rs files (any change, no matter how small)
• Reviewing, refactoring, or rewriting code Rust code

Which guideline to read and when

Before writing or modifying Rust code, Claude must load ONLY the guideline files that apply to the requested task, using segmented reading (offset and limit) when needed.

Guidelines and when they apply

1. 01_ai_guidelines.md

Use when the Rust code involves:

• AI agents and LLM-driven code generation
• Making APIs easier for AI systems to use
• Comprehensive documentation and detailed examples
• Strong type systems that help AI avoid mistakes

2. 02_application_guidelines.md

Use when working on:

• Application-level error handling with anyhow or eyre
• CLI tools and desktop applications
• Performance optimization using mimalloc allocator
• User-facing features and initialization logic

3. 03_documentation_guidelines.md

Use when:

• Writing public API documentation and doc comments
• Creating canonical documentation sections (Examples, Errors, Panics, Safety)
• Structuring module-level documentation comprehensively
• Re-exporting items and using #[doc(inline)] annotations

4. 04_ffi_guidelines.md

Use when:

• Loading multiple Rust-based dynamic libraries (DLLs)
• Creating FFI boundaries and interoperability layers
• Sharing data between different Rust compilation artifacts
• Dealing with portable vs non-portable data types across DLL boundaries

5. 05_library_guidelines.md

Use when creating or modifying Rust libraries, including:

• Structuring a crate
• Designing public APIs
• Dependency decisions

6. 06_performance_guidelines.md

Use when:

• Identifying and profiling hot paths in your code
• Optimizing for throughput and CPU cycle efficiency
• Managing allocation patterns and memory usage
• Implementing yield points in long-running async tasks

7. 07_safety_guidelines.md

Use when:

• Writing unsafe code for novel abstractions, performance, or FFI
• Ensuring code soundness and preventing undefined behavior
• Documenting safety requirements and invariants
• Reviewing unsafe blocks for correctness with Miri

8. 08_universal_guidelines.md

Use in ALL Rust tasks. This file defines:

• General Rust best practices applicable to all code
• Style, naming, and organizational conventions
• Cross-cutting concerns that apply everywhere
• Foundational principles for any Rust project

9. 09_libraries_building_guidelines.md

Use when:

• Creating reusable library crates
• Managing Cargo features and their additivity
• Building native -sys crates for C interoperability
• Ensuring libraries work out-of-the-box on all platforms

10. 10_libraries_interoperability_guidelines.md

Use when:

• Exposing public APIs and managing external dependencies
• Designing types for Send/Sync compatibility
• Avoiding leaking third-party types from public APIs
• Creating escape hatches for native handle interop

11. 11_libraries_resilience_guidelines.md

Use when:

• Avoiding statics and thread-local state in libraries
• Making I/O and system calls mockable for testing
• Preventing glob re-exports and accidental leaks
• Feature-gating test utilities and mocking functionality

12. 12_libraries_ux_guidelines.md

Use when:

• Designing user-friendly library APIs
• Managing error types and error handling patterns
• Creating runtime abstractions and trait-based designs
• Structuring crate organization and public interfaces

Coding Rules

1. Load the necessary guideline files BEFORE ANY RUST CODE GENERATION.
2. Apply the required rules from the relevant guidelines.
3. Apply the M-CANONICAL-DOCS documentation format.
4. Comments must ALWAYS be written in American English, unless the user explicitly requests ‘write comments in French’ or provides another clear instruction specifying a different comment language.
5. If the file is fully compliant, add a comment: // Rust guideline compliant {date} where {date} is the guideline date or the date of the current day (format YYYY-MM-DD)