Ownership Introduction
Rust's ownership system manages memory and ensures safety without a garbage collector. It enforces rules at compile time, preventing common errors like double frees or memory leaks, which are common in other systems languages.
Ownership Rules
Rust's ownership rules are strict: each value has a single owner, when the owner goes out of scope, the value is dropped, and while variables can transfer ownership, they cannot unintentionally share it, preventing dangling references.
Ownership and Functions
Passing a variable to a function transfers ownership, called 'move'. If you want to use a value after passing it to a function, you must use borrowing or cloning to maintain the original ownership.
Borrowing in Rust
Borrowing allows access to data without ownership transfer. There are two types: immutable references, which allow multiple reads, and mutable references, exclusive to prevent data races. Borrowing enforces Rust's safety guarantees at compile time.
Slices - Ownership Alternative
Slices are a non-ownership view into a data structure. They are a safe way to reference a sequence within a collection without copying. Slices let you access parts of collections while enforcing memory safety.
Lifetime Annotations
Lifetime annotations don't change Rust's ownership, but they make relationships between borrows explicit to the compiler. This ensures that references are valid as long as the data they point to, preventing dangling references.
Ownership in Concurrency
Rust's ownership rules are pivotal for concurrency. They prevent data races at compile time by ensuring that mutable data cannot be concurrently accessed by multiple threads, leading to safer concurrent programming without the usual headaches.