Understanding Rust's ownership and type system through output prediction
This is an easy question that asks you to trace through a Rust code snippet and predict what gets printed. It tests your working knowledge of Rust's core language mechanics—ownership, borrowing, type inference, and how the compiler transforms your code into runtime behaviour.
Candidates solving this problem need to mentally execute the code, keeping track of how values move or are borrowed, what types the compiler infers, and whether any implicit conversions or trait implementations affect the output. These questions are common in Rust interview rounds because they quickly separate candidates who have written real Rust code from those who have only skimmed the documentation.
- Ownership and move semantics
- Borrowing and lifetime rules
- Type inference and coercion
- Trait implementations and method resolution