[Extract field inside of optional struct as an option] Use this when you want to extract a field from an optional struct and keep that field also as an option type #rust

map_option.rs

struct User {
	id: i32,
}

// fn do_something_with_user_id(Option<i32>);

// Bad, simple solution
fn something(user_option: Option<User>) {
   let user_id_option = if let Some(user) = user_option { Some(user.id) } else { None };
   do_something_with_user_id(user_id_option);
}

// Good, Elegant solution
// Option::map applies a function to the contained value only and leaves None as is
fn something(user_option: Option<User>) {
   let user_id_option = user_option.map(|user| user.id);
   do_something_with_user_id(user_id_option);
}