Drop order

Understanding Rust's drop order for multiple values

This is a medium-difficulty Rust language question that tests your understanding of how the compiler handles resource cleanup and ownership semantics. It requires you to reason about the precise order in which values are deallocated when they go out of scope—a critical concept for writing correct and predictable Rust code.

To answer questions like this, you need to trace through Rust's scoping rules and understand that variables are dropped in reverse order of their declaration. This knowledge becomes essential when working with types that implement custom Drop implementations, managing file handles, locks, or other resources where cleanup order matters. Interviewers probe this area to confirm you can reason about Rust's deterministic cleanup semantics rather than relying on garbage collection intuition.

• Variable scope and lexical ordering
• The Drop trait and custom destructors
• Resource acquisition and cleanup guarantees
• Interaction between ownership and deallocation