thiserror for library errors

anyhow in binary/application

Custom error enum

? operator propagation

No bare unwrap()

expect() with messages

Error context added

std::error::Error impl

Doctests present

From conversions

Unit tests in cfg(test)

No String error return

spawn_blocking for sync I/O

tokio::sync primitives

Channels for communication

JoinHandle results handled

No lock held across await

Timeout on I/O

select! for cancellation

try_join! for concurrent fallibles

async-trait for async methods in traits

tokio::test for async tests

No unwrap() in production

Associated types in traits

&str over String params

&[T] over Vec<T> params

Derive macros used

Standard traits implemented

No unnecessary clones

proptest property tests

criterion benchmark

Focused small traits

Doctest in documentation

Static dispatch preferred

cfg(test) unit tests

Arc<Mutex<T>> for shared state

Cow<str> for conditional allocation

Explicit lifetime annotations

&str params not String

&[T] params not Vec<T>

No unnecessary clones

No unwrap() in production

Lifetime documentation

Doctests present

Design decisions explained

Safety comment per unsafe block

Unsafe surface minimised

Drop trait for cleanup

BufferGuard uses Drop for RAII

Type-system compile-time safety

No unwrap() in production

Custom error type

Doctests present

Unit tests cover unsafe paths

Trait abstraction for testability

mockall used for unit tests

Integration tests in tests/ directory

Test fixture with Drop cleanup

cargo fmt evidence

cargo clippy evidence

cargo test --doc evidence

anyhow in binary/application

bail! or ensure! usage

Doctests present

thiserror for library errors