Ownership semantics

Understanding ownership transfer across different types in Rust

This easy question probes whether you grasp the fundamental distinction between types that implement Copy and those that do not—a cornerstone of Rust's ownership model. When you call a function with an argument, Rust either moves ownership or copies the value; understanding which applies when is essential to writing code that compiles and reasoning about memory safety.

The question guides you to articulate why certain types (like primitive integers) behave differently from heap-allocated types (like String) when passed as function arguments. The answer hinges on cost, determinism, and what the language can guarantee about duplicating a value safely. Interviewers often follow up by asking how Copy interacts with Drop, or whether you'd ever want a type to not be Copy even if it could be.

• The Copy trait and its prerequisites
• Stack vs. heap allocation and move semantics
• Ownership transfer as a zero-cost abstraction