| #[cfg(feature = "vec_map")] | 
 | pub use vec_map::{Values, VecMap}; | 
 |  | 
 | #[cfg(not(feature = "vec_map"))] | 
 | pub use self::vec_map::{Values, VecMap}; | 
 |  | 
 | #[cfg(not(feature = "vec_map"))] | 
 | mod vec_map { | 
 |     use std::collections::BTreeMap; | 
 |     use std::collections::btree_map; | 
 |     use std::fmt::{self, Debug, Formatter}; | 
 |  | 
 |     #[derive(Clone, Default, Debug)] | 
 |     pub struct VecMap<V> { | 
 |         inner: BTreeMap<usize, V>, | 
 |     } | 
 |  | 
 |     impl<V> VecMap<V> { | 
 |         pub fn new() -> Self { | 
 |             VecMap { | 
 |                 inner: Default::default(), | 
 |             } | 
 |         } | 
 |  | 
 |         pub fn len(&self) -> usize { self.inner.len() } | 
 |  | 
 |         pub fn is_empty(&self) -> bool { self.inner.is_empty() } | 
 |  | 
 |         pub fn insert(&mut self, key: usize, value: V) -> Option<V> { | 
 |             self.inner.insert(key, value) | 
 |         } | 
 |  | 
 |         pub fn values(&self) -> Values<V> { self.inner.values() } | 
 |  | 
 |         pub fn iter(&self) -> Iter<V> { | 
 |             Iter { | 
 |                 inner: self.inner.iter(), | 
 |             } | 
 |         } | 
 |  | 
 |         pub fn contains_key(&self, key: usize) -> bool { self.inner.contains_key(&key) } | 
 |  | 
 |         pub fn entry(&mut self, key: usize) -> Entry<V> { self.inner.entry(key) } | 
 |  | 
 |         pub fn get(&self, key: usize) -> Option<&V> { self.inner.get(&key) } | 
 |     } | 
 |  | 
 |     pub type Values<'a, V> = btree_map::Values<'a, usize, V>; | 
 |  | 
 |     pub type Entry<'a, V> = btree_map::Entry<'a, usize, V>; | 
 |  | 
 |     #[derive(Clone)] | 
 |     pub struct Iter<'a, V: 'a> { | 
 |         inner: btree_map::Iter<'a, usize, V>, | 
 |     } | 
 |  | 
 |     impl<'a, V: 'a + Debug> Debug for Iter<'a, V> { | 
 |         fn fmt(&self, f: &mut Formatter) -> fmt::Result { | 
 |             f.debug_list().entries(self.inner.clone()).finish() | 
 |         } | 
 |     } | 
 |  | 
 |     impl<'a, V: 'a> Iterator for Iter<'a, V> { | 
 |         type Item = (usize, &'a V); | 
 |  | 
 |         fn next(&mut self) -> Option<Self::Item> { self.inner.next().map(|(k, v)| (*k, v)) } | 
 |     } | 
 |  | 
 |     impl<'a, V: 'a> DoubleEndedIterator for Iter<'a, V> { | 
 |         fn next_back(&mut self) -> Option<Self::Item> { | 
 |             self.inner.next_back().map(|(k, v)| (*k, v)) | 
 |         } | 
 |     } | 
 | } |