vendor/rustc-ap-rustc_data_structures/src/stable_set.rs

   1 pub use rustc_hash::FxHashSet;
   2 use std::borrow::Borrow;
   3 use std::fmt;
   4 use std::hash::Hash;
   5
   6 /// A deterministic wrapper around FxHashSet that does not provide iteration support.
   7 ///
   8 /// It supports insert, remove, get functions from FxHashSet.
   9 /// It also allows to convert hashset to a sorted vector with the method `into_sorted_vector()`.
  10 #[derive(Clone)]
  11 pub struct StableSet<T> {
  12     base: FxHashSet<T>,
  13 }
  14
  15 impl<T> Default for StableSet<T>
  16 where
  17     T: Eq + Hash,
  18 {
  19     fn default() -> StableSet<T> {
  20         StableSet::new()
  21     }
  22 }
  23
  24 impl<T> fmt::Debug for StableSet<T>
  25 where
  26     T: Eq + Hash + fmt::Debug,
  27 {
  28     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  29         write!(f, "{:?}", self.base)
  30     }
  31 }
  32
  33 impl<T> PartialEq<StableSet<T>> for StableSet<T>
  34 where
  35     T: Eq + Hash,
  36 {
  37     fn eq(&self, other: &StableSet<T>) -> bool {
  38         self.base == other.base
  39     }
  40 }
  41
  42 impl<T> Eq for StableSet<T> where T: Eq + Hash {}
  43
  44 impl<T: Hash + Eq> StableSet<T> {
  45     pub fn new() -> StableSet<T> {
  46         StableSet { base: FxHashSet::default() }
  47     }
  48
  49     pub fn into_sorted_vector(self) -> Vec<T>
  50     where
  51         T: Ord,
  52     {
  53         let mut vector = self.base.into_iter().collect::<Vec<_>>();
  54         vector.sort_unstable();
  55         vector
  56     }
  57
  58     pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T>
  59     where
  60         T: Borrow<Q>,
  61         Q: Hash + Eq,
  62     {
  63         self.base.get(value)
  64     }
  65
  66     pub fn insert(&mut self, value: T) -> bool {
  67         self.base.insert(value)
  68     }
  69
  70     pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool
  71     where
  72         T: Borrow<Q>,
  73         Q: Hash + Eq,
  74     {
  75         self.base.remove(value)
  76     }
  77 }