rust-essentials

Rust Essentials

RULES

1. Read the crate instructions, Cargo.toml, Cargo.lock, toolchain file, and the nearest relevant source or test. Follow existing architecture and dependencies.
2. Verify every crate API, feature, or import path against the locked version using local crate source/docs or a minimal compile. Do not infer APIs from newer examples.
3. Parse untrusted input at boundaries. Add types only for meaningful invariants; borrow when ownership need not transfer.
4. Use Result and ? for expected failures. Add a dependency only when needed and after verifying its pinned API.
5. Keep unsafe rare and document the invariant that makes each block sound.

Example

• ✅ Confirm the locked crate version and compile the API use before relying on it.
• ❌ Copy an API from the latest online example without checking the project's version.

Validation

In the target crate, run cargo fmt --check, cargo check, and focused tests. For behavior changes, add and run a regression test; run cargo clippy --all-targets -- -D warnings and cargo test when supported.

Integration

This is the baseline for ownership-borrowing, type-driven-design, and error-handling.