Welcome to this lesson on borrowing and references in Rust! Rust is known for its unique approach to memory management, which emphasizes safety and concurrency. One of the fundamental concepts in Rust is ownership, which governs how memory is allocated and deallocated. Understanding borrowing and references is crucial for writing efficient and safe Rust programs.

In this lesson, we will explore:

• Borrowing Immutable References: How to access variables without transferring ownership.
• Borrowing Mutable References: How to modify data through references without ownership changes.
• Rules of Mutable References: The constraints Rust imposes to ensure safe modifications.
• Dangling References: How Rust prevents pointers to non-existent objects and ensures memory safety.

By the end of this lesson, you will have a solid understanding of how to use borrowing and references in Rust to write more efficient and safer code. Let's dive in!

Rust defaults to transferring a variable's ownership when it's passed to a function. If we want to pass a variable to a function without transferring ownership, Rust uses the borrowing mechanism. To do this, the function signature declares its input as a reference (in this case s: &String). To call the function, pass a reference to a variable (in this case &title).