Reference material

Identifying undefined behavior in Rust code

This is a hard difficulty question that tests whether you can spot unsafe patterns and memory-safety violations in Rust. It probes your understanding of the language's formal safety guarantees and the precise conditions under which undefined behavior can occur—knowledge that is essential for systems programming and performance-critical roles.

Working through this requires you to reason carefully about lifetimes, pointer validity, ownership rules, and the boundaries between safe and unsafe code. You must distinguish between code that merely looks suspicious and code that actually violates Rust's safety contract. This includes understanding when unsafe blocks are necessary, how raw pointers can be misused, and what invariants the compiler assumes when optimizing around your code.

• Unsafe code blocks and their contracts
• Pointer dereferencing and validity
• Lifetime violations and use-after-free
• Mutable and immutable borrowing rules
• Memory alignment and data races