A quick multiple-choice check before you move on. Answer every question, then submit to see how you did.
1.You have a file src/parser.rs in a library crate, but nowhere in the crate does any code write mod parser;. What happens when you build?
2.Given a module outer that contains a private function helper() and a child module inner, which access is allowed by Rust's visibility rules?
3.A C# developer marks a top-level type with no access modifier and expects it to be internal (visible across the assembly). What is the equivalent Rust default visibility for an item, and its pub(...) counterpart?
4.A crate's real code lives at internals::math::add, but lib.rs contains pub use internals::math::add;. What does this accomplish?
5.You define pub struct Config { name: String } in module settings and access it as crate::settings::Config from elsewhere in the crate. Why does reading config.name from outside settings fail to compile?