Remove key duplication from BTreeMap example in collections

src/libstd/collections/mod.rs

@@ -332,8 +332,8 @@
 //! ```
 //! use std::collections::btree_map::BTreeMap;
 //!
-//! // A client of the bar. They have an id and a blood alcohol level.
-//! struct Person { id: u32, blood_alcohol: f32 }
+//! // A client of the bar. They have a blood alcohol level.
+//! struct Person { blood_alcohol: f32 }
 //!
 //! // All the orders made to the bar, by client id.
 //! let orders = vec![1,2,1,2,3,4,1,2,2,3,4,1,1,1];
@@ -344,15 +344,15 @@
 //! for id in orders {
 //!     // If this is the first time we've seen this customer, initialize them
 //!     // with no blood alcohol. Otherwise, just retrieve them.
-//!     let person = blood_alcohol.entry(id).or_insert(Person{id: id, blood_alcohol: 0.0});
+//!     let person = blood_alcohol.entry(id).or_insert(Person { blood_alcohol: 0.0 });
 //!
 //!     // Reduce their blood alcohol level. It takes time to order and drink a beer!
 //!     person.blood_alcohol *= 0.9;
 //!
 //!     // Check if they're sober enough to have another beer.
 //!     if person.blood_alcohol > 0.3 {
 //!         // Too drunk... for now.
-//!         println!("Sorry {}, I have to cut you off", person.id);
+//!         println!("Sorry {}, I have to cut you off", id);
 //!     } else {
 //!         // Have another!
 //!         person.blood_alcohol += 0.1;