Compare Pairs
Option.as_mut vs RefCall.borrow_mut
outer mutability &mutvsinterior mutability &- Compile-time vs Runtime for Borrow Rules
Option::map vs Option::unwrap()
map handle both Some and None, avoids explicit unwrapping,reducing the risk of panics and making code more declarative.
There are two flavors of map in Rust, one for iterator map (many values), one for Option tranformed.
map follow a functional programming pattern: take a container, apply a transformation to its concents, and return a new container of the same kind.