rust-best-practices

Return Result<T, E> for fallible operations and propagate errors with the ? operator instead of unwrap or expect. Use thiserror to define typed errors in libraries and anyhow only in binaries or main entry points where a catch-all with context is acceptable.

Use thiserror for library errors that callers need to match on, since it derives Display, Error, and From impls for precise typed errors. Reserve anyhow for binaries where ergonomic context chaining matters more than precise error types.

Prefer borrowing with &T over .clone(), use &str and &[T] in function parameters, and pass small Copy types by value. Run cargo clippy with the redundant_clone lint to detect accidental clones, and use Cow when ownership is ambiguous.

Run cargo clippy --all-targets --all-features --locked -- -D warnings as a baseline. Key lints include redundant_clone, large_enum_variant, needless_collect, and clone_on_copy, configurable per workspace in Cargo.toml under [lints.clippy].

Prefer generics with static dispatch for performance-critical code since monomorphization produces inlined specialized code. Use dyn Trait only when you need heterogeneous collections, plugin architectures, or runtime polymorphism, accepting the vtable indirection cost.

unwrap and expect panic on failure, crashing the application instead of propagating recoverable errors. Alternatives include the ? operator, let-else patterns for early returns, and unwrap_or_else or unwrap_or_default for fallback values.