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//! A linked hash set implementation based on the `linked_hash_map` crate.
//! See [`LinkedHashSet`](struct.LinkedHashSet.html).
//!
//! # Examples
//!
//! ```
//! let mut set = linked_hash_set::LinkedHashSet::new();
//! assert!(set.insert(234));
//! assert!(set.insert(123));
//! assert!(set.insert(345));
//! assert!(!set.insert(123)); // Also see `insert_if_absent` which won't change order
//!
//! assert_eq!(set.into_iter().collect::<Vec<_>>(), vec![234, 345, 123]);
//! ```
#[cfg(feature = "serde")]
pub mod serde;
use linked_hash_map as map;
use linked_hash_map::{Keys, LinkedHashMap};
use std::borrow::Borrow;
use std::collections::hash_map::RandomState;
use std::fmt;
use std::hash::{BuildHasher, Hash, Hasher};
use std::iter::{Chain, FromIterator};
use std::ops::{BitAnd, BitOr, BitXor, Sub};
// Note: This implementation is adapted from std `HashSet` implementation ~2017-10
// parts relying on std `HashMap` functionality that is not present in `LinkedHashMap` or
// relying on private access to map internals have been removed.
/// A linked hash set implemented as a `linked_hash_map::LinkedHashMap` where the value is
/// `()`, in a similar way std `HashSet` is implemented from `HashMap`.
///
/// General usage is very similar to a std `HashSet`. However, a `LinkedHashSet` **maintains
/// insertion order** using a doubly-linked list running through its entries. As such methods
/// [`front()`], [`pop_front()`], [`back()`] and [`pop_back()`] are provided.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// // Type inference lets us omit an explicit type signature (which
/// // would be `LinkedHashSet<&str>` in this example).
/// let mut books = LinkedHashSet::new();
///
/// // Add some books.
/// books.insert("A Dance With Dragons");
/// books.insert("To Kill a Mockingbird");
/// books.insert("The Odyssey");
/// books.insert("The Great Gatsby");
///
/// // Check for a specific one.
/// if !books.contains("The Winds of Winter") {
/// println!(
/// "We have {} books, but The Winds of Winter ain't one.",
/// books.len()
/// );
/// }
///
/// // Remove a book.
/// books.remove("The Odyssey");
///
/// // Remove the first inserted book.
/// books.pop_front();
///
/// // Iterate over the remaining books in insertion order.
/// for book in &books {
/// println!("{}", book);
/// }
///
/// assert_eq!(
/// books.into_iter().collect::<Vec<_>>(),
/// vec!["To Kill a Mockingbird", "The Great Gatsby"]
/// );
/// ```
///
/// The easiest way to use `LinkedHashSet` with a custom type is to derive
/// `Eq` and `Hash`. We must also derive `PartialEq`, this will in the
/// future be implied by `Eq`.
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// #[derive(Hash, Eq, PartialEq, Debug)]
/// struct Viking<'a> {
/// name: &'a str,
/// power: usize,
/// }
///
/// let mut vikings = LinkedHashSet::new();
///
/// vikings.insert(Viking {
/// name: "Einar",
/// power: 9,
/// });
/// vikings.insert(Viking {
/// name: "Einar",
/// power: 9,
/// });
/// vikings.insert(Viking {
/// name: "Olaf",
/// power: 4,
/// });
/// vikings.insert(Viking {
/// name: "Harald",
/// power: 8,
/// });
///
/// // Use derived implementation to print the vikings.
/// for x in &vikings {
/// println!("{:?}", x);
/// }
/// ```
///
/// A `LinkedHashSet` with fixed list of elements can be initialized from an array:
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// fn main() {
/// let viking_names: LinkedHashSet<&str> =
/// ["Einar", "Olaf", "Harald"].iter().cloned().collect();
/// // use the values stored in the set
/// }
/// ```
///
/// [`front()`]: struct.LinkedHashSet.html#method.front
/// [`pop_front()`]: struct.LinkedHashSet.html#method.pop_front
/// [`back()`]: struct.LinkedHashSet.html#method.back
/// [`pop_back()`]: struct.LinkedHashSet.html#method.pop_back
pub struct LinkedHashSet<T, S = RandomState> {
map: LinkedHashMap<T, (), S>,
}
impl<T: Hash + Eq> LinkedHashSet<T, RandomState> {
/// Creates an empty `LinkedHashSet`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// let set: LinkedHashSet<i32> = LinkedHashSet::new();
/// ```
#[inline]
pub fn new() -> LinkedHashSet<T, RandomState> {
LinkedHashSet {
map: LinkedHashMap::new(),
}
}
/// Creates an empty `LinkedHashSet` with the specified capacity.
///
/// The hash set will be able to hold at least `capacity` elements without
/// reallocating. If `capacity` is 0, the hash set will not allocate.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// let set: LinkedHashSet<i32> = LinkedHashSet::with_capacity(10);
/// assert!(set.capacity() >= 10);
/// ```
#[inline]
pub fn with_capacity(capacity: usize) -> LinkedHashSet<T, RandomState> {
LinkedHashSet {
map: LinkedHashMap::with_capacity(capacity),
}
}
}
impl<T, S> LinkedHashSet<T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
/// Creates a new empty hash set which will use the given hasher to hash
/// keys.
///
/// The hash set is also created with the default initial capacity.
///
/// Warning: `hasher` is normally randomly generated, and
/// is designed to allow `LinkedHashSet`s to be resistant to attacks that
/// cause many collisions and very poor performance. Setting it
/// manually using this function can expose a DoS attack vector.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// use std::collections::hash_map::RandomState;
///
/// let s = RandomState::new();
/// let mut set = LinkedHashSet::with_hasher(s);
/// set.insert(2);
/// ```
#[inline]
pub fn with_hasher(hasher: S) -> LinkedHashSet<T, S> {
LinkedHashSet {
map: LinkedHashMap::with_hasher(hasher),
}
}
/// Creates an empty `LinkedHashSet` with with the specified capacity, using
/// `hasher` to hash the keys.
///
/// The hash set will be able to hold at least `capacity` elements without
/// reallocating. If `capacity` is 0, the hash set will not allocate.
///
/// Warning: `hasher` is normally randomly generated, and
/// is designed to allow `LinkedHashSet`s to be resistant to attacks that
/// cause many collisions and very poor performance. Setting it
/// manually using this function can expose a DoS attack vector.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// use std::collections::hash_map::RandomState;
///
/// let s = RandomState::new();
/// let mut set = LinkedHashSet::with_capacity_and_hasher(10, s);
/// set.insert(1);
/// ```
#[inline]
pub fn with_capacity_and_hasher(capacity: usize, hasher: S) -> LinkedHashSet<T, S> {
LinkedHashSet {
map: LinkedHashMap::with_capacity_and_hasher(capacity, hasher),
}
}
/// Returns a reference to the set's `BuildHasher`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// use std::collections::hash_map::RandomState;
///
/// let hasher = RandomState::new();
/// let set: LinkedHashSet<i32> = LinkedHashSet::with_hasher(hasher);
/// let hasher: &RandomState = set.hasher();
/// ```
pub fn hasher(&self) -> &S {
self.map.hasher()
}
/// Returns the number of elements the set can hold without reallocating.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// let set: LinkedHashSet<i32> = LinkedHashSet::with_capacity(100);
/// assert!(set.capacity() >= 100);
/// ```
#[inline]
pub fn capacity(&self) -> usize {
self.map.capacity()
}
/// Reserves capacity for at least `additional` more elements to be inserted
/// in the `LinkedHashSet`. The collection may reserve more space to avoid
/// frequent reallocations.
///
/// # Panics
///
/// Panics if the new allocation size overflows `usize`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// let mut set: LinkedHashSet<i32> = LinkedHashSet::new();
/// set.reserve(10);
/// assert!(set.capacity() >= 10);
/// ```
pub fn reserve(&mut self, additional: usize) {
self.map.reserve(additional)
}
/// Shrinks the capacity of the set as much as possible. It will drop
/// down as much as possible while maintaining the internal rules
/// and possibly leaving some space in accordance with the resize policy.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let mut set = LinkedHashSet::with_capacity(100);
/// set.insert(1);
/// set.insert(2);
/// assert!(set.capacity() >= 100);
/// set.shrink_to_fit();
/// assert!(set.capacity() >= 2);
/// ```
pub fn shrink_to_fit(&mut self) {
self.map.shrink_to_fit()
}
/// An iterator visiting all elements in insertion order.
/// The iterator element type is `&'a T`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// let mut set = LinkedHashSet::new();
/// set.insert("a");
/// set.insert("b");
///
/// // Will print in an insertion order.
/// for x in set.iter() {
/// println!("{}", x);
/// }
/// ```
pub fn iter(&self) -> Iter<'_, T> {
Iter {
iter: self.map.keys(),
}
}
/// Visits the values representing the difference,
/// i.e. the values that are in `self` but not in `other`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// let a: LinkedHashSet<_> = [1, 2, 3].iter().cloned().collect();
/// let b: LinkedHashSet<_> = [4, 2, 3, 4].iter().cloned().collect();
///
/// // Can be seen as `a - b`.
/// for x in a.difference(&b) {
/// println!("{}", x); // Print 1
/// }
///
/// let diff: LinkedHashSet<_> = a.difference(&b).collect();
/// assert_eq!(diff, [1].iter().collect());
///
/// // Note that difference is not symmetric,
/// // and `b - a` means something else:
/// let diff: LinkedHashSet<_> = b.difference(&a).collect();
/// assert_eq!(diff, [4].iter().collect());
/// ```
pub fn difference<'a>(&'a self, other: &'a LinkedHashSet<T, S>) -> Difference<'a, T, S> {
Difference {
iter: self.iter(),
other,
}
}
/// Visits the values representing the symmetric difference,
/// i.e. the values that are in `self` or in `other` but not in both.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// let a: LinkedHashSet<_> = [1, 2, 3].iter().cloned().collect();
/// let b: LinkedHashSet<_> = [4, 2, 3, 4].iter().cloned().collect();
///
/// // Print 1, 4 in insertion order.
/// for x in a.symmetric_difference(&b) {
/// println!("{}", x);
/// }
///
/// let diff1: LinkedHashSet<_> = a.symmetric_difference(&b).collect();
/// let diff2: LinkedHashSet<_> = b.symmetric_difference(&a).collect();
///
/// assert_eq!(diff1, diff2);
/// assert_eq!(diff1, [1, 4].iter().collect());
/// ```
pub fn symmetric_difference<'a>(
&'a self,
other: &'a LinkedHashSet<T, S>,
) -> SymmetricDifference<'a, T, S> {
SymmetricDifference {
iter: self.difference(other).chain(other.difference(self)),
}
}
/// Visits the values representing the intersection,
/// i.e. the values that are both in `self` and `other`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// let a: LinkedHashSet<_> = [1, 2, 3].iter().cloned().collect();
/// let b: LinkedHashSet<_> = [4, 2, 3, 4].iter().cloned().collect();
///
/// // Print 2, 3 in insertion order.
/// for x in a.intersection(&b) {
/// println!("{}", x);
/// }
///
/// let intersection: LinkedHashSet<_> = a.intersection(&b).collect();
/// assert_eq!(intersection, [2, 3].iter().collect());
/// ```
pub fn intersection<'a>(&'a self, other: &'a LinkedHashSet<T, S>) -> Intersection<'a, T, S> {
Intersection {
iter: self.iter(),
other,
}
}
/// Visits the values representing the union,
/// i.e. all the values in `self` or `other`, without duplicates.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// let a: LinkedHashSet<_> = [1, 2, 3].iter().cloned().collect();
/// let b: LinkedHashSet<_> = [4, 2, 3, 4].iter().cloned().collect();
///
/// // Print 1, 2, 3, 4 in insertion order.
/// for x in a.union(&b) {
/// println!("{}", x);
/// }
///
/// let union: LinkedHashSet<_> = a.union(&b).collect();
/// assert_eq!(union, [1, 2, 3, 4].iter().collect());
/// ```
pub fn union<'a>(&'a self, other: &'a LinkedHashSet<T, S>) -> Union<'a, T, S> {
Union {
iter: self.iter().chain(other.difference(self)),
}
}
/// Returns the number of elements in the set.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let mut v = LinkedHashSet::new();
/// assert_eq!(v.len(), 0);
/// v.insert(1);
/// assert_eq!(v.len(), 1);
/// ```
pub fn len(&self) -> usize {
self.map.len()
}
/// Returns true if the set contains no elements.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let mut v = LinkedHashSet::new();
/// assert!(v.is_empty());
/// v.insert(1);
/// assert!(!v.is_empty());
/// ```
pub fn is_empty(&self) -> bool {
self.map.is_empty()
}
// TODO not in linked_hash_map
// /// Clears the set, returning all elements in an iterator.
// ///
// /// # Examples
// ///
// /// ```
// /// use linked_hash_set::LinkedHashSet;
// ///
// /// let mut set: LinkedHashSet<_> = [1, 2, 3].iter().cloned().collect();
// /// assert!(!set.is_empty());
// ///
// /// // print 1, 2, 3 in an insertion order
// /// for i in set.drain() {
// /// println!("{}", i);
// /// }
// ///
// /// assert!(set.is_empty());
// /// ```
// #[inline]
// pub fn drain(&mut self) -> Drain<T> {
// Drain { iter: self.map.drain() }
// }
/// Clears the set, removing all values.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let mut v = LinkedHashSet::new();
/// v.insert(1);
/// v.clear();
/// assert!(v.is_empty());
/// ```
pub fn clear(&mut self) {
self.map.clear()
}
/// Returns `true` if the set contains a value.
///
/// The value may be any borrowed form of the set's value type, but
/// `Hash` and `Eq` on the borrowed form *must* match those for
/// the value type.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let set: LinkedHashSet<_> = [1, 2, 3].iter().cloned().collect();
/// assert_eq!(set.contains(&1), true);
/// assert_eq!(set.contains(&4), false);
/// ```
pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool
where
T: Borrow<Q>,
Q: Hash + Eq,
{
self.map.contains_key(value)
}
/// If already present, moves a value to the end of the ordering.
///
/// If the set did have this value present, `true` is returned.
///
/// If the set did not have this value present, `false` is returned.
///
/// Similar to `LinkedHashMap::get_refresh`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let mut set: LinkedHashSet<_> = [1, 2, 3].iter().cloned().collect();
/// let was_refreshed = set.refresh(&2);
///
/// assert_eq!(was_refreshed, true);
/// assert_eq!(set.into_iter().collect::<Vec<_>>(), vec![1, 3, 2]);
/// ```
pub fn refresh<Q: ?Sized>(&mut self, value: &Q) -> bool
where
T: Borrow<Q>,
Q: Hash + Eq,
{
self.map.get_refresh(value).is_some()
}
// TODO Non-trivial port without private access to map
// /// Returns a reference to the value in the set, if any, that is equal to the given value.
// ///
// /// The value may be any borrowed form of the set's value type, but
// /// `Hash` and `Eq` on the borrowed form *must* match those for
// /// the value type.
// pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T>
// where T: Borrow<Q>,
// Q: Hash + Eq
// {
// Recover::get(&self.map, value)
// }
/// Returns `true` if `self` has no elements in common with `other`.
/// This is equivalent to checking for an empty intersection.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let a: LinkedHashSet<_> = [1, 2, 3].iter().cloned().collect();
/// let mut b = LinkedHashSet::new();
///
/// assert_eq!(a.is_disjoint(&b), true);
/// b.insert(4);
/// assert_eq!(a.is_disjoint(&b), true);
/// b.insert(1);
/// assert_eq!(a.is_disjoint(&b), false);
/// ```
pub fn is_disjoint(&self, other: &LinkedHashSet<T, S>) -> bool {
self.iter().all(|v| !other.contains(v))
}
/// Returns `true` if the set is a subset of another,
/// i.e. `other` contains at least all the values in `self`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let sup: LinkedHashSet<_> = [1, 2, 3].iter().cloned().collect();
/// let mut set = LinkedHashSet::new();
///
/// assert_eq!(set.is_subset(&sup), true);
/// set.insert(2);
/// assert_eq!(set.is_subset(&sup), true);
/// set.insert(4);
/// assert_eq!(set.is_subset(&sup), false);
/// ```
pub fn is_subset(&self, other: &LinkedHashSet<T, S>) -> bool {
self.iter().all(|v| other.contains(v))
}
/// Returns `true` if the set is a superset of another,
/// i.e. `self` contains at least all the values in `other`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let sub: LinkedHashSet<_> = [1, 2].iter().cloned().collect();
/// let mut set = LinkedHashSet::new();
///
/// assert_eq!(set.is_superset(&sub), false);
///
/// set.insert(0);
/// set.insert(1);
/// assert_eq!(set.is_superset(&sub), false);
///
/// set.insert(2);
/// assert_eq!(set.is_superset(&sub), true);
/// ```
#[inline]
pub fn is_superset(&self, other: &LinkedHashSet<T, S>) -> bool {
other.is_subset(self)
}
/// Adds a value to the set.
///
/// If the set did not have this value present, `true` is returned.
///
/// If the set did have this value present, `false` is returned.
///
/// Note that performing this action will always place the value at the end of the ordering
/// whether the set already contained the value or not. Also see
/// [`insert_if_absent`](#method.insert_if_absent).
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let mut set = LinkedHashSet::new();
///
/// assert_eq!(set.insert(2), true);
/// assert_eq!(set.insert(2), false);
/// assert_eq!(set.len(), 1);
/// ```
pub fn insert(&mut self, value: T) -> bool {
self.map.insert(value, ()).is_none()
}
/// Adds a value to the set, if not already present. The distinction with `insert` is that
/// order of elements is unaffected when calling this method for a value already contained.
///
/// If the set did not have this value present, `true` is returned.
///
/// If the set did have this value present, `false` is returned.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let mut set = LinkedHashSet::new();
///
/// assert_eq!(set.insert_if_absent(2), true);
/// assert_eq!(set.insert_if_absent(2), false);
/// assert_eq!(set.len(), 1);
/// ```
pub fn insert_if_absent(&mut self, value: T) -> bool {
if !self.map.contains_key(&value) {
self.map.insert(value, ()).is_none()
} else {
false
}
}
// TODO Non-trivial port without private access to map
// /// Adds a value to the set, replacing the existing value, if any, that is equal to the given
// /// one. Returns the replaced value.
// pub fn replace(&mut self, value: T) -> Option<T> {
// Recover::replace(&mut self.map, value)
// }
/// Removes a value from the set. Returns `true` if the value was
/// present in the set.
///
/// The value may be any borrowed form of the set's value type, but
/// `Hash` and `Eq` on the borrowed form *must* match those for
/// the value type.
///
/// This operation will not affect the ordering of the other elements.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let mut set = LinkedHashSet::new();
///
/// set.insert(2);
/// assert_eq!(set.remove(&2), true);
/// assert_eq!(set.remove(&2), false);
/// ```
pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool
where
T: Borrow<Q>,
Q: Hash + Eq,
{
self.map.remove(value).is_some()
}
// TODO Non-trivial port without private access to map
// /// Removes and returns the value in the set, if any, that is equal to the given one.
// ///
// /// The value may be any borrowed form of the set's value type, but
// /// `Hash` and `Eq` on the borrowed form *must* match those for
// /// the value type.
// pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T>
// where T: Borrow<Q>,
// Q: Hash + Eq
// {
// Recover::take(&mut self.map, value)
// }
// TODO not in linked_hash_map
// /// Retains only the elements specified by the predicate.
// ///
// /// In other words, remove all elements `e` such that `f(&e)` returns `false`.
// ///
// /// # Examples
// ///
// /// ```
// /// use linked_hash_set::LinkedHashSet;
// ///
// /// let xs = [1,2,3,4,5,6];
// /// let mut set: LinkedHashSet<isize> = xs.iter().cloned().collect();
// /// set.retain(|&k| k % 2 == 0);
// /// assert_eq!(set.len(), 3);
// /// ```
// pub fn retain<F>(&mut self, mut f: F)
// where F: FnMut(&T) -> bool
// {
// self.map.retain(|k, _| f(k));
// }
/// Gets the first entry.
pub fn front(&self) -> Option<&T> {
self.map.front().map(|(k, _)| k)
}
/// Removes the first entry.
pub fn pop_front(&mut self) -> Option<T> {
self.map.pop_front().map(|(k, _)| k)
}
/// Gets the last entry.
pub fn back(&mut self) -> Option<&T> {
self.map.back().map(|(k, _)| k)
}
/// Removes the last entry.
pub fn pop_back(&mut self) -> Option<T> {
self.map.pop_back().map(|(k, _)| k)
}
}
impl<T: Hash + Eq + Clone, S: BuildHasher + Clone> Clone for LinkedHashSet<T, S> {
fn clone(&self) -> Self {
let map = self.map.clone();
Self { map }
}
}
impl<T, S> PartialEq for LinkedHashSet<T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
fn eq(&self, other: &LinkedHashSet<T, S>) -> bool {
if self.len() != other.len() {
return false;
}
self.iter().all(|key| other.contains(key))
}
}
impl<T, S> Hash for LinkedHashSet<T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
fn hash<H: Hasher>(&self, state: &mut H) {
for e in self {
e.hash(state);
}
}
}
impl<T, S> Eq for LinkedHashSet<T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
}
impl<T, S> fmt::Debug for LinkedHashSet<T, S>
where
T: Eq + Hash + fmt::Debug,
S: BuildHasher,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_set().entries(self.iter()).finish()
}
}
impl<T, S> FromIterator<T> for LinkedHashSet<T, S>
where
T: Eq + Hash,
S: BuildHasher + Default,
{
fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> LinkedHashSet<T, S> {
let mut set = LinkedHashSet::with_hasher(Default::default());
set.extend(iter);
set
}
}
impl<T, S> Extend<T> for LinkedHashSet<T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
self.map.extend(iter.into_iter().map(|k| (k, ())));
}
}
impl<'a, T, S> Extend<&'a T> for LinkedHashSet<T, S>
where
T: 'a + Eq + Hash + Copy,
S: BuildHasher,
{
fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) {
self.extend(iter.into_iter().cloned());
}
}
impl<T, S> Default for LinkedHashSet<T, S>
where
T: Eq + Hash,
S: BuildHasher + Default,
{
/// Creates an empty `LinkedHashSet<T, S>` with the `Default` value for the hasher.
fn default() -> LinkedHashSet<T, S> {
LinkedHashSet {
map: LinkedHashMap::default(),
}
}
}
impl<'a, 'b, T, S> BitOr<&'b LinkedHashSet<T, S>> for &'a LinkedHashSet<T, S>
where
T: Eq + Hash + Clone,
S: BuildHasher + Default,
{
type Output = LinkedHashSet<T, S>;
/// Returns the union of `self` and `rhs` as a new `LinkedHashSet<T, S>`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let a: LinkedHashSet<_> = vec![1, 2, 3].into_iter().collect();
/// let b: LinkedHashSet<_> = vec![3, 4, 5].into_iter().collect();
///
/// let set = &a | &b;
///
/// let mut i = 0;
/// let expected = [1, 2, 3, 4, 5];
/// for x in &set {
/// assert!(expected.contains(x));
/// i += 1;
/// }
/// assert_eq!(i, expected.len());
/// ```
fn bitor(self, rhs: &LinkedHashSet<T, S>) -> LinkedHashSet<T, S> {
self.union(rhs).cloned().collect()
}
}
impl<'a, 'b, T, S> BitAnd<&'b LinkedHashSet<T, S>> for &'a LinkedHashSet<T, S>
where
T: Eq + Hash + Clone,
S: BuildHasher + Default,
{
type Output = LinkedHashSet<T, S>;
/// Returns the intersection of `self` and `rhs` as a new `LinkedHashSet<T, S>`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let a: LinkedHashSet<_> = vec![1, 2, 3].into_iter().collect();
/// let b: LinkedHashSet<_> = vec![2, 3, 4].into_iter().collect();
///
/// let set = &a & &b;
///
/// let mut i = 0;
/// let expected = [2, 3];
/// for x in &set {
/// assert!(expected.contains(x));
/// i += 1;
/// }
/// assert_eq!(i, expected.len());
/// ```
fn bitand(self, rhs: &LinkedHashSet<T, S>) -> LinkedHashSet<T, S> {
self.intersection(rhs).cloned().collect()
}
}
impl<'a, 'b, T, S> BitXor<&'b LinkedHashSet<T, S>> for &'a LinkedHashSet<T, S>
where
T: Eq + Hash + Clone,
S: BuildHasher + Default,
{
type Output = LinkedHashSet<T, S>;
/// Returns the symmetric difference of `self` and `rhs` as a new `LinkedHashSet<T, S>`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let a: LinkedHashSet<_> = vec![1, 2, 3].into_iter().collect();
/// let b: LinkedHashSet<_> = vec![3, 4, 5].into_iter().collect();
///
/// let set = &a ^ &b;
///
/// let mut i = 0;
/// let expected = [1, 2, 4, 5];
/// for x in &set {
/// assert!(expected.contains(x));
/// i += 1;
/// }
/// assert_eq!(i, expected.len());
/// ```
fn bitxor(self, rhs: &LinkedHashSet<T, S>) -> LinkedHashSet<T, S> {
self.symmetric_difference(rhs).cloned().collect()
}
}
impl<'a, 'b, T, S> Sub<&'b LinkedHashSet<T, S>> for &'a LinkedHashSet<T, S>
where
T: Eq + Hash + Clone,
S: BuildHasher + Default,
{
type Output = LinkedHashSet<T, S>;
/// Returns the difference of `self` and `rhs` as a new `LinkedHashSet<T, S>`.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
///
/// let a: LinkedHashSet<_> = vec![1, 2, 3].into_iter().collect();
/// let b: LinkedHashSet<_> = vec![3, 4, 5].into_iter().collect();
///
/// let set = &a - &b;
///
/// let mut i = 0;
/// let expected = [1, 2];
/// for x in &set {
/// assert!(expected.contains(x));
/// i += 1;
/// }
/// assert_eq!(i, expected.len());
/// ```
fn sub(self, rhs: &LinkedHashSet<T, S>) -> LinkedHashSet<T, S> {
self.difference(rhs).cloned().collect()
}
}
/// An iterator over the items of a `LinkedHashSet`.
///
/// This `struct` is created by the [`iter`] method on [`LinkedHashSet`].
/// See its documentation for more.
/// [`LinkedHashSet`]: struct.LinkedHashSet.html
/// [`iter`]: struct.LinkedHashSet.html#method.iter
pub struct Iter<'a, K> {
iter: Keys<'a, K, ()>,
}
/// An owning iterator over the items of a `LinkedHashSet`.
///
/// This `struct` is created by the [`into_iter`] method on [`LinkedHashSet`][`LinkedHashSet`]
/// (provided by the `IntoIterator` trait). See its documentation for more.
///
/// [`LinkedHashSet`]: struct.LinkedHashSet.html
/// [`into_iter`]: struct.LinkedHashSet.html#method.into_iter
pub struct IntoIter<K> {
iter: map::IntoIter<K, ()>,
}
// TODO not in linked_hash_map
// /// A draining iterator over the items of a `LinkedHashSet`.
// ///
// /// This `struct` is created by the [`drain`] method on [`LinkedHashSet`].
// /// See its documentation for more.
// ///
// /// [`LinkedHashSet`]: struct.LinkedHashSet.html
// /// [`drain`]: struct.LinkedHashSet.html#method.drain
// pub struct Drain<'a, K: 'a> {
// iter: map::Drain<'a, K, ()>,
// }
/// A lazy iterator producing elements in the intersection of `LinkedHashSet`s.
///
/// This `struct` is created by the [`intersection`] method on [`LinkedHashSet`].
/// See its documentation for more.
///
/// [`LinkedHashSet`]: struct.LinkedHashSet.html
/// [`intersection`]: struct.LinkedHashSet.html#method.intersection
pub struct Intersection<'a, T, S> {
// iterator of the first set
iter: Iter<'a, T>,
// the second set
other: &'a LinkedHashSet<T, S>,
}
/// A lazy iterator producing elements in the difference of `LinkedHashSet`s.
///
/// This `struct` is created by the [`difference`] method on [`LinkedHashSet`].
/// See its documentation for more.
///
/// [`LinkedHashSet`]: struct.LinkedHashSet.html
/// [`difference`]: struct.LinkedHashSet.html#method.difference
pub struct Difference<'a, T, S> {
// iterator of the first set
iter: Iter<'a, T>,
// the second set
other: &'a LinkedHashSet<T, S>,
}
/// A lazy iterator producing elements in the symmetric difference of `LinkedHashSet`s.
///
/// This `struct` is created by the [`symmetric_difference`] method on
/// [`LinkedHashSet`]. See its documentation for more.
///
/// [`LinkedHashSet`]: struct.LinkedHashSet.html
/// [`symmetric_difference`]: struct.LinkedHashSet.html#method.symmetric_difference
pub struct SymmetricDifference<'a, T, S> {
iter: Chain<Difference<'a, T, S>, Difference<'a, T, S>>,
}
/// A lazy iterator producing elements in the union of `LinkedHashSet`s.
///
/// This `struct` is created by the [`union`] method on [`LinkedHashSet`].
/// See its documentation for more.
///
/// [`LinkedHashSet`]: struct.LinkedHashSet.html
/// [`union`]: struct.LinkedHashSet.html#method.union
pub struct Union<'a, T, S> {
iter: Chain<Iter<'a, T>, Difference<'a, T, S>>,
}
impl<'a, T, S> IntoIterator for &'a LinkedHashSet<T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
type Item = &'a T;
type IntoIter = Iter<'a, T>;
fn into_iter(self) -> Iter<'a, T> {
self.iter()
}
}
impl<T, S> IntoIterator for LinkedHashSet<T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
type Item = T;
type IntoIter = IntoIter<T>;
/// Creates a consuming iterator, that is, one that moves each value out
/// of the set in insertion order. The set cannot be used after calling
/// this.
///
/// # Examples
///
/// ```
/// use linked_hash_set::LinkedHashSet;
/// let mut set = LinkedHashSet::new();
/// set.insert("a".to_string());
/// set.insert("b".to_string());
///
/// // Not possible to collect to a Vec<String> with a regular `.iter()`.
/// let v: Vec<String> = set.into_iter().collect();
///
/// // Will print in an insertion order.
/// for x in &v {
/// println!("{}", x);
/// }
/// ```
fn into_iter(self) -> IntoIter<T> {
IntoIter {
iter: self.map.into_iter(),
}
}
}
impl<'a, K> Clone for Iter<'a, K> {
fn clone(&self) -> Iter<'a, K> {
Iter {
iter: self.iter.clone(),
}
}
}
impl<'a, K> Iterator for Iter<'a, K> {
type Item = &'a K;
fn next(&mut self) -> Option<&'a K> {
self.iter.next()
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl<'a, K> ExactSizeIterator for Iter<'a, K> {
fn len(&self) -> usize {
self.iter.len()
}
}
impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
fn next_back(&mut self) -> Option<&'a T> {
self.iter.next_back()
}
}
impl<'a, K: fmt::Debug> fmt::Debug for Iter<'a, K> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
impl<K> Iterator for IntoIter<K> {
type Item = K;
fn next(&mut self) -> Option<K> {
self.iter.next().map(|(k, _)| k)
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl<K> ExactSizeIterator for IntoIter<K> {
fn len(&self) -> usize {
self.iter.len()
}
}
impl<K> DoubleEndedIterator for IntoIter<K> {
fn next_back(&mut self) -> Option<K> {
self.iter.next_back().map(|(k, _)| k)
}
}
// TODO Non-trivial port without private access to map
// impl<K: fmt::Debug> fmt::Debug for IntoIter<K> {
// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
// let entries_iter = self.iter
// .inner
// .iter()
// .map(|(k, _)| k);
// f.debug_list().entries(entries_iter).finish()
// }
// }
// TODO not in linked_hash_map
// impl<'a, K> Iterator for Drain<'a, K> {
// type Item = K;
//
// fn next(&mut self) -> Option<K> {
// self.iter.next().map(|(k, _)| k)
// }
// fn size_hint(&self) -> (usize, Option<usize>) {
// self.iter.size_hint()
// }
// }
// impl<'a, K> ExactSizeIterator for Drain<'a, K> {
// fn len(&self) -> usize {
// self.iter.len()
// }
// }
//
// impl<'a, K: fmt::Debug> fmt::Debug for Drain<'a, K> {
// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
// let entries_iter = self.iter
// .inner
// .iter()
// .map(|(k, _)| k);
// f.debug_list().entries(entries_iter).finish()
// }
// }
impl<'a, T, S> Clone for Intersection<'a, T, S> {
fn clone(&self) -> Intersection<'a, T, S> {
Intersection {
iter: self.iter.clone(),
..*self
}
}
}
impl<'a, T, S> Iterator for Intersection<'a, T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
type Item = &'a T;
fn next(&mut self) -> Option<&'a T> {
loop {
match self.iter.next() {
None => return None,
Some(elt) => {
if self.other.contains(elt) {
return Some(elt);
}
}
}
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
let (_, upper) = self.iter.size_hint();
(0, upper)
}
}
impl<'a, T, S> fmt::Debug for Intersection<'a, T, S>
where
T: fmt::Debug + Eq + Hash,
S: BuildHasher,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
impl<'a, T, S> Clone for Difference<'a, T, S> {
fn clone(&self) -> Difference<'a, T, S> {
Difference {
iter: self.iter.clone(),
..*self
}
}
}
impl<'a, T, S> Iterator for Difference<'a, T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
type Item = &'a T;
fn next(&mut self) -> Option<&'a T> {
loop {
match self.iter.next() {
None => return None,
Some(elt) => {
if !self.other.contains(elt) {
return Some(elt);
}
}
}
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
let (_, upper) = self.iter.size_hint();
(0, upper)
}
}
impl<'a, T, S> fmt::Debug for Difference<'a, T, S>
where
T: fmt::Debug + Eq + Hash,
S: BuildHasher,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
impl<'a, T, S> Clone for SymmetricDifference<'a, T, S> {
fn clone(&self) -> SymmetricDifference<'a, T, S> {
SymmetricDifference {
iter: self.iter.clone(),
}
}
}
impl<'a, T, S> Iterator for SymmetricDifference<'a, T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
type Item = &'a T;
fn next(&mut self) -> Option<&'a T> {
self.iter.next()
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl<'a, T, S> fmt::Debug for SymmetricDifference<'a, T, S>
where
T: fmt::Debug + Eq + Hash,
S: BuildHasher,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
impl<'a, T, S> Clone for Union<'a, T, S> {
fn clone(&self) -> Union<'a, T, S> {
Union {
iter: self.iter.clone(),
}
}
}
impl<'a, T, S> fmt::Debug for Union<'a, T, S>
where
T: fmt::Debug + Eq + Hash,
S: BuildHasher,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.clone()).finish()
}
}
impl<'a, T, S> Iterator for Union<'a, T, S>
where
T: Eq + Hash,
S: BuildHasher,
{
type Item = &'a T;
fn next(&mut self) -> Option<&'a T> {
self.iter.next()
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
// TODO does not currently work like HashSet-HashMap with linked_hash_map
// #[allow(dead_code)]
// fn assert_covariance() {
// fn set<'new>(v: LinkedHashSet<&'static str>) -> LinkedHashSet<&'new str> {
// v
// }
// fn iter<'a, 'new>(v: Iter<'a, &'static str>) -> Iter<'a, &'new str> {
// v
// }
// fn into_iter<'new>(v: IntoIter<&'static str>) -> IntoIter<&'new str> {
// v
// }
// fn difference<'a, 'new>(v: Difference<'a, &'static str, RandomState>)
// -> Difference<'a, &'new str, RandomState> {
// v
// }
// fn symmetric_difference<'a, 'new>(v: SymmetricDifference<'a, &'static str, RandomState>)
// -> SymmetricDifference<'a, &'new str, RandomState> {
// v
// }
// fn intersection<'a, 'new>(v: Intersection<'a, &'static str, RandomState>)
// -> Intersection<'a, &'new str, RandomState> {
// v
// }
// fn union<'a, 'new>(v: Union<'a, &'static str, RandomState>)
// -> Union<'a, &'new str, RandomState> {
// v
// }
// fn drain<'new>(d: Drain<'static, &'static str>) -> Drain<'new, &'new str> {
// d
// }
// }
// Tests in common with `HashSet`
#[cfg(test)]
mod test_set {
use super::*;
#[test]
fn test_zero_capacities() {
type HS = LinkedHashSet<i32>;
let s = HS::new();
assert_eq!(s.capacity(), 0);
let s = HS::default();
assert_eq!(s.capacity(), 0);
let s = HS::with_hasher(RandomState::new());
assert_eq!(s.capacity(), 0);
let s = HS::with_capacity(0);
assert_eq!(s.capacity(), 0);
let s = HS::with_capacity_and_hasher(0, RandomState::new());
assert_eq!(s.capacity(), 0);
let mut s = HS::new();
s.insert(1);
s.insert(2);
s.remove(&1);
s.remove(&2);
s.shrink_to_fit();
assert_eq!(s.capacity(), 0);
let mut s = HS::new();
s.reserve(0);
assert_eq!(s.capacity(), 0);
}
#[test]
fn test_disjoint() {
let mut xs = LinkedHashSet::new();
let mut ys = LinkedHashSet::new();
assert!(xs.is_disjoint(&ys));
assert!(ys.is_disjoint(&xs));
assert!(xs.insert(5));
assert!(ys.insert(11));
assert!(xs.is_disjoint(&ys));
assert!(ys.is_disjoint(&xs));
assert!(xs.insert(7));
assert!(xs.insert(19));
assert!(xs.insert(4));
assert!(ys.insert(2));
assert!(ys.insert(-11));
assert!(xs.is_disjoint(&ys));
assert!(ys.is_disjoint(&xs));
assert!(ys.insert(7));
assert!(!xs.is_disjoint(&ys));
assert!(!ys.is_disjoint(&xs));
}
#[test]
fn test_subset_and_superset() {
let mut a = LinkedHashSet::new();
assert!(a.insert(0));
assert!(a.insert(5));
assert!(a.insert(11));
assert!(a.insert(7));
let mut b = LinkedHashSet::new();
assert!(b.insert(0));
assert!(b.insert(7));
assert!(b.insert(19));
assert!(b.insert(250));
assert!(b.insert(11));
assert!(b.insert(200));
assert!(!a.is_subset(&b));
assert!(!a.is_superset(&b));
assert!(!b.is_subset(&a));
assert!(!b.is_superset(&a));
assert!(b.insert(5));
assert!(a.is_subset(&b));
assert!(!a.is_superset(&b));
assert!(!b.is_subset(&a));
assert!(b.is_superset(&a));
}
#[test]
fn test_iterate() {
let mut a = LinkedHashSet::new();
for i in 0..32 {
assert!(a.insert(i));
}
let mut observed: u32 = 0;
for k in &a {
observed |= 1 << *k;
}
assert_eq!(observed, 0xFFFF_FFFF);
}
#[test]
fn test_intersection() {
let mut a = LinkedHashSet::new();
let mut b = LinkedHashSet::new();
assert!(a.insert(11));
assert!(a.insert(1));
assert!(a.insert(3));
assert!(a.insert(77));
assert!(a.insert(103));
assert!(a.insert(5));
assert!(a.insert(-5));
assert!(b.insert(2));
assert!(b.insert(11));
assert!(b.insert(77));
assert!(b.insert(-9));
assert!(b.insert(-42));
assert!(b.insert(5));
assert!(b.insert(3));
let mut i = 0;
let expected = [3, 5, 11, 77];
for x in a.intersection(&b) {
assert!(expected.contains(x));
i += 1
}
assert_eq!(i, expected.len());
}
#[test]
fn test_difference() {
let mut a = LinkedHashSet::new();
let mut b = LinkedHashSet::new();
assert!(a.insert(1));
assert!(a.insert(3));
assert!(a.insert(5));
assert!(a.insert(9));
assert!(a.insert(11));
assert!(b.insert(3));
assert!(b.insert(9));
let mut i = 0;
let expected = [1, 5, 11];
for x in a.difference(&b) {
assert!(expected.contains(x));
i += 1
}
assert_eq!(i, expected.len());
}
#[test]
fn test_symmetric_difference() {
let mut a = LinkedHashSet::new();
let mut b = LinkedHashSet::new();
assert!(a.insert(1));
assert!(a.insert(3));
assert!(a.insert(5));
assert!(a.insert(9));
assert!(a.insert(11));
assert!(b.insert(-2));
assert!(b.insert(3));
assert!(b.insert(9));
assert!(b.insert(14));
assert!(b.insert(22));
let mut i = 0;
let expected = [-2, 1, 5, 11, 14, 22];
for x in a.symmetric_difference(&b) {
assert!(expected.contains(x));
i += 1
}
assert_eq!(i, expected.len());
}
#[test]
fn test_union() {
let mut a = LinkedHashSet::new();
let mut b = LinkedHashSet::new();
assert!(a.insert(1));
assert!(a.insert(3));
assert!(a.insert(5));
assert!(a.insert(9));
assert!(a.insert(11));
assert!(a.insert(16));
assert!(a.insert(19));
assert!(a.insert(24));
assert!(b.insert(-2));
assert!(b.insert(1));
assert!(b.insert(5));
assert!(b.insert(9));
assert!(b.insert(13));
assert!(b.insert(19));
let mut i = 0;
let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24];
for x in a.union(&b) {
assert!(expected.contains(x));
i += 1
}
assert_eq!(i, expected.len());
}
#[test]
fn test_from_iter() {
let xs = [1, 2, 3, 4, 5, 6, 7, 8, 9];
let set: LinkedHashSet<_> = xs.iter().cloned().collect();
for x in &xs {
assert!(set.contains(x));
}
}
#[test]
fn test_move_iter() {
let hs = {
let mut hs = LinkedHashSet::new();
hs.insert('a');
hs.insert('b');
hs
};
let v = hs.into_iter().collect::<Vec<char>>();
assert!(v == ['a', 'b'] || v == ['b', 'a']);
}
#[test]
fn test_eq() {
// These constants once happened to expose a bug in insert().
// I'm keeping them around to prevent a regression.
let mut s1 = LinkedHashSet::new();
s1.insert(1);
s1.insert(2);
s1.insert(3);
let mut s2 = LinkedHashSet::new();
s2.insert(1);
s2.insert(2);
assert!(s1 != s2);
s2.insert(3);
assert_eq!(s1, s2);
}
#[test]
fn test_show() {
let mut set = LinkedHashSet::new();
let empty = LinkedHashSet::<i32>::new();
set.insert(1);
set.insert(2);
let set_str = format!("{:?}", set);
assert!(set_str == "{1, 2}" || set_str == "{2, 1}");
assert_eq!(format!("{:?}", empty), "{}");
}
// #[test]
// fn test_trivial_drain() {
// let mut s = LinkedHashSet::<i32>::new();
// for _ in s.drain() {}
// assert!(s.is_empty());
// drop(s);
//
// let mut s = LinkedHashSet::<i32>::new();
// drop(s.drain());
// assert!(s.is_empty());
// }
// #[test]
// fn test_drain() {
// let mut s: LinkedHashSet<_> = (1..100).collect();
//
// // try this a bunch of times to make sure we don't screw up internal state.
// for _ in 0..20 {
// assert_eq!(s.len(), 99);
//
// {
// let mut last_i = 0;
// let mut d = s.drain();
// for (i, x) in d.by_ref().take(50).enumerate() {
// last_i = i;
// assert!(x != 0);
// }
// assert_eq!(last_i, 49);
// }
//
// for _ in &s {
// panic!("s should be empty!");
// }
//
// // reset to try again.
// s.extend(1..100);
// }
// }
// #[test]
// fn test_replace() {
// use std::hash;
//
// #[derive(Debug)]
// struct Foo(&'static str, i32);
//
// impl PartialEq for Foo {
// fn eq(&self, other: &Self) -> bool {
// self.0 == other.0
// }
// }
//
// impl Eq for Foo {}
//
// impl hash::Hash for Foo {
// fn hash<H: hash::Hasher>(&self, h: &mut H) {
// self.0.hash(h);
// }
// }
//
// let mut s = LinkedHashSet::new();
// assert_eq!(s.replace(Foo("a", 1)), None);
// assert_eq!(s.len(), 1);
// assert_eq!(s.replace(Foo("a", 2)), Some(Foo("a", 1)));
// assert_eq!(s.len(), 1);
//
// let mut it = s.iter();
// assert_eq!(it.next(), Some(&Foo("a", 2)));
// assert_eq!(it.next(), None);
// }
#[test]
fn test_extend_ref() {
let mut a = LinkedHashSet::new();
a.insert(1);
a.extend(&[2, 3, 4]);
assert_eq!(a.len(), 4);
assert!(a.contains(&1));
assert!(a.contains(&2));
assert!(a.contains(&3));
assert!(a.contains(&4));
let mut b = LinkedHashSet::new();
b.insert(5);
b.insert(6);
a.extend(&b);
assert_eq!(a.len(), 6);
assert!(a.contains(&1));
assert!(a.contains(&2));
assert!(a.contains(&3));
assert!(a.contains(&4));
assert!(a.contains(&5));
assert!(a.contains(&6));
}
// #[test]
// fn test_retain() {
// let xs = [1, 2, 3, 4, 5, 6];
// let mut set: LinkedHashSet<isize> = xs.iter().cloned().collect();
// set.retain(|&k| k % 2 == 0);
// assert_eq!(set.len(), 3);
// assert!(set.contains(&2));
// assert!(set.contains(&4));
// assert!(set.contains(&6));
// }
}
// Tests for `LinkedHashSet` functionality over `HashSet`
#[cfg(test)]
mod test_linked {
use super::*;
macro_rules! set {
($($el:expr),*) => {{
let mut set = LinkedHashSet::new();
$(
set.insert($el);
)*
set
}}
}
#[test]
fn order_is_maintained() {
let set = set![123, 234, 56, 677];
assert_eq!(set.into_iter().collect::<Vec<_>>(), vec![123, 234, 56, 677]);
}
#[test]
fn clone_order_is_maintained() {
let set = set![123, 234, 56, 677];
assert_eq!(
set.clone().into_iter().collect::<Vec<_>>(),
vec![123, 234, 56, 677]
);
}
#[test]
fn delegate_front() {
let set = set![123, 234, 56, 677];
assert_eq!(set.front(), Some(&123));
}
#[test]
fn delegate_pop_front() {
let mut set = set![123, 234, 56, 677];
assert_eq!(set.pop_front(), Some(123));
assert_eq!(set.into_iter().collect::<Vec<_>>(), vec![234, 56, 677]);
}
#[test]
fn delegate_back() {
let mut set = set![123, 234, 56, 677];
assert_eq!(set.back(), Some(&677));
}
#[test]
fn delegate_pop_back() {
let mut set = set![123, 234, 56, 677];
assert_eq!(set.pop_back(), Some(677));
assert_eq!(set.into_iter().collect::<Vec<_>>(), vec![123, 234, 56]);
}
#[test]
fn double_ended_iter() {
let set = set![123, 234, 56, 677];
let mut iter = set.iter();
assert_eq!(iter.next(), Some(&123));
assert_eq!(iter.next(), Some(&234));
assert_eq!(iter.next_back(), Some(&677));
assert_eq!(iter.next_back(), Some(&56));
assert_eq!(iter.next(), None);
assert_eq!(iter.next_back(), None);
}
#[test]
fn double_ended_into_iter() {
let mut iter = set![123, 234, 56, 677].into_iter();
assert_eq!(iter.next(), Some(123));
assert_eq!(iter.next_back(), Some(677));
assert_eq!(iter.next_back(), Some(56));
assert_eq!(iter.next_back(), Some(234));
assert_eq!(iter.next(), None);
assert_eq!(iter.next_back(), None);
}
}