Closures

How Rust closures capture their environment, and why Fn, FnMut, and FnOnce are ownership-aware interfaces rather than three arbitrary categories.

Syntax, inference, and capturing the environment.

The closure traits and how capture mode is chosen.

Transferring ownership into closures and threads.

Passing and composing behavior.

Functional data transformations.

Trade-offs and interop.

Capturing minimally and avoiding lifetime traps.