| use std::collections::HashSet; |
| use std::hash::Hash; |
| use std::slice; |
| |
| pub struct OrderedSet<'a, T> { |
| set: HashSet<&'a T>, |
| vec: Vec<&'a T>, |
| } |
| |
| impl<'a, T> OrderedSet<'a, T> |
| where |
| T: Hash + Eq, |
| { |
| pub fn new() -> Self { |
| OrderedSet { |
| set: HashSet::new(), |
| vec: Vec::new(), |
| } |
| } |
| |
| pub fn insert(&mut self, value: &'a T) -> bool { |
| let new = self.set.insert(value); |
| if new { |
| self.vec.push(value); |
| } |
| new |
| } |
| |
| pub fn contains(&self, value: &T) -> bool { |
| self.set.contains(value) |
| } |
| } |
| |
| impl<'s, 'a, T> IntoIterator for &'s OrderedSet<'a, T> { |
| type Item = &'a T; |
| type IntoIter = Iter<'s, 'a, T>; |
| fn into_iter(self) -> Self::IntoIter { |
| Iter(self.vec.iter()) |
| } |
| } |
| |
| pub struct Iter<'s, 'a, T>(slice::Iter<'s, &'a T>); |
| |
| impl<'s, 'a, T> Iterator for Iter<'s, 'a, T> { |
| type Item = &'a T; |
| fn next(&mut self) -> Option<Self::Item> { |
| self.0.next().copied() |
| } |
| } |