|  | //! Compare `insert` and `insert_unique_unchecked` operations performance. | 
|  |  | 
|  | #![feature(test)] | 
|  |  | 
|  | extern crate test; | 
|  |  | 
|  | use hashbrown::HashMap; | 
|  | use test::Bencher; | 
|  |  | 
|  | #[bench] | 
|  | fn insert(b: &mut Bencher) { | 
|  | let keys: Vec<String> = (0..1000).map(|i| format!("xxxx{}yyyy", i)).collect(); | 
|  | b.iter(|| { | 
|  | let mut m = HashMap::with_capacity(1000); | 
|  | for k in &keys { | 
|  | m.insert(k, k); | 
|  | } | 
|  | m | 
|  | }); | 
|  | } | 
|  |  | 
|  | #[bench] | 
|  | fn insert_unique_unchecked(b: &mut Bencher) { | 
|  | let keys: Vec<String> = (0..1000).map(|i| format!("xxxx{}yyyy", i)).collect(); | 
|  | b.iter(|| { | 
|  | let mut m = HashMap::with_capacity(1000); | 
|  | for k in &keys { | 
|  | m.insert_unique_unchecked(k, k); | 
|  | } | 
|  | m | 
|  | }); | 
|  | } |