To be precise, Rust will refuse to compile code that accesses the value without checking that it is not empty. Rust does that with the combination of "sum type

To be precise, Rust will refuse to compile code that accesses the value without checking that it is not empty. Rust does that with the combination of "sum types" (aka "enums with data") and pattern matching. An `Option<T>` is either `Some(T)` or `None`. Matching on an option with the pattern `Some(value)` creates a new syntactic scope where the value is accessible. This scope is only entered if the `Option` is actually non-empty. All ways of getting the value from the option are ultimately shorthand for a match in that way. For example, option.unwrap() will either get the value if it there, or panic. Option.unwrap_or(x) will either get the value of it there, or use x instead. In practice this is x100 less error prone than C++. Source: was burned by vector.front() on empty vectors more than once. In C++, UB. In rust, usually the "empty case" is considered when first writing the code, or at least caught during review (unwraps tend to be very visible in reviews)