Struct heapless::IndexSet[−][src]

pub struct IndexSet<T, N, S> where
    T: Eq + Hash,
    N: ArrayLength<Bucket<T, ()>> + ArrayLength<Option<Pos>>,  { /* fields omitted */ }
Expand description

Fixed capacity IndexSet.

Note that you cannot use IndexSet directly, since it is generic around the hashing algorithm in use. Pick a concrete instantiation like FnvIndexSet instead or create your own.

Note that the capacity of the IndexSet must be a power of 2.

Examples

Since IndexSet cannot be used directly, we’re using its FnvIndexSet instantiation for this example.

use heapless::FnvIndexSet;
use heapless::consts::*;

// A hash set with a capacity of 16 elements allocated on the stack
let mut books = FnvIndexSet::<_, U16>::new();

// Add some books.
books.insert("A Dance With Dragons").unwrap();
books.insert("To Kill a Mockingbird").unwrap();
books.insert("The Odyssey").unwrap();
books.insert("The Great Gatsby").unwrap();

// 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");

// Iterate over everything.
for book in &books {
    println!("{}", book);
}

Implementations

Creates an empty IndexSet

Returns the number of elements the set can hold

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let set = FnvIndexSet::<i32, U16>::new();
assert_eq!(set.capacity(), 16);

Return an iterator over the values of the set, in their order

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let mut set = FnvIndexSet::<_, U16>::new();
set.insert("a").unwrap();
set.insert("b").unwrap();

// Will print in an arbitrary order.
for x in set.iter() {
    println!("{}", x);
}

Visits the values representing the difference, i.e. the values that are in self but not in other.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let mut a: FnvIndexSet<_, U16> = [1, 2, 3].iter().cloned().collect();
let mut b: FnvIndexSet<_, U16> = [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: FnvIndexSet<_, U16> = a.difference(&b).collect();
assert_eq!(diff, [1].iter().collect::<FnvIndexSet<_, U16>>());

// Note that difference is not symmetric,
// and `b - a` means something else:
let diff: FnvIndexSet<_, U16> = b.difference(&a).collect();
assert_eq!(diff, [4].iter().collect::<FnvIndexSet<_, U16>>());

Visits the values representing the symmetric difference, i.e. the values that are in self or in other but not in both.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let mut a: FnvIndexSet<_, U16> = [1, 2, 3].iter().cloned().collect();
let mut b: FnvIndexSet<_, U16> = [4, 2, 3, 4].iter().cloned().collect();

// Print 1, 4 in that order order.
for x in a.symmetric_difference(&b) {
    println!("{}", x);
}

let diff1: FnvIndexSet<_, U16> = a.symmetric_difference(&b).collect();
let diff2: FnvIndexSet<_, U16> = b.symmetric_difference(&a).collect();

assert_eq!(diff1, diff2);
assert_eq!(diff1, [1, 4].iter().collect::<FnvIndexSet<_, U16>>());

Visits the values representing the intersection, i.e. the values that are both in self and other.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let mut a: FnvIndexSet<_, U16> = [1, 2, 3].iter().cloned().collect();
let mut b: FnvIndexSet<_, U16> = [4, 2, 3, 4].iter().cloned().collect();

// Print 2, 3 in that order.
for x in a.intersection(&b) {
    println!("{}", x);
}

let intersection: FnvIndexSet<_, U16> = a.intersection(&b).collect();
assert_eq!(intersection, [2, 3].iter().collect::<FnvIndexSet<_, U16>>());

Visits the values representing the union, i.e. all the values in self or other, without duplicates.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let mut a: FnvIndexSet<_, U16> = [1, 2, 3].iter().cloned().collect();
let mut b: FnvIndexSet<_, U16> = [4, 2, 3, 4].iter().cloned().collect();

// Print 1, 2, 3, 4 in that order.
for x in a.union(&b) {
    println!("{}", x);
}

let union: FnvIndexSet<_, U16> = a.union(&b).collect();
assert_eq!(union, [1, 2, 3, 4].iter().collect::<FnvIndexSet<_, U16>>());

Returns the number of elements in the set.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let mut v: FnvIndexSet<_, U16> = FnvIndexSet::new();
assert_eq!(v.len(), 0);
v.insert(1).unwrap();
assert_eq!(v.len(), 1);

Returns true if the set contains no elements.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let mut v: FnvIndexSet<_, U16> = FnvIndexSet::new();
assert!(v.is_empty());
v.insert(1).unwrap();
assert!(!v.is_empty());

Clears the set, removing all values.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let mut v: FnvIndexSet<_, U16> = FnvIndexSet::new();
v.insert(1).unwrap();
v.clear();
assert!(v.is_empty());

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 heapless::FnvIndexSet;
use heapless::consts::*;

let set: FnvIndexSet<_, U16> = [1, 2, 3].iter().cloned().collect();
assert_eq!(set.contains(&1), true);
assert_eq!(set.contains(&4), false);

Returns true if self has no elements in common with other. This is equivalent to checking for an empty intersection.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let a: FnvIndexSet<_, U16> = [1, 2, 3].iter().cloned().collect();
let mut b = FnvIndexSet::<_, U16>::new();

assert_eq!(a.is_disjoint(&b), true);
b.insert(4).unwrap();
assert_eq!(a.is_disjoint(&b), true);
b.insert(1).unwrap();
assert_eq!(a.is_disjoint(&b), false);

Returns true if the set is a subset of another, i.e. other contains at least all the values in self.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let sup: FnvIndexSet<_, U16> = [1, 2, 3].iter().cloned().collect();
let mut set = FnvIndexSet::<_, U16>::new();

assert_eq!(set.is_subset(&sup), true);
set.insert(2).unwrap();
assert_eq!(set.is_subset(&sup), true);
set.insert(4).unwrap();
assert_eq!(set.is_subset(&sup), false);

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let sub: FnvIndexSet<_, U16> = [1, 2].iter().cloned().collect();
let mut set = FnvIndexSet::<_, U16>::new();

assert_eq!(set.is_superset(&sub), false);

set.insert(0).unwrap();
set.insert(1).unwrap();
assert_eq!(set.is_superset(&sub), false);

set.insert(2).unwrap();
assert_eq!(set.is_superset(&sub), true);

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.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let mut set = FnvIndexSet::<_, U16>::new();

assert_eq!(set.insert(2).unwrap(), true);
assert_eq!(set.insert(2).unwrap(), false);
assert_eq!(set.len(), 1);

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.

Examples

use heapless::FnvIndexSet;
use heapless::consts::*;

let mut set = FnvIndexSet::<_, U16>::new();

set.insert(2).unwrap();
assert_eq!(set.remove(&2), true);
assert_eq!(set.remove(&2), false);

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Returns the “default value” for a type. Read more

Extends a collection with the contents of an iterator. Read more

🔬 This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

🔬 This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements. Read more

Extends a collection with the contents of an iterator. Read more

🔬 This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

🔬 This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements. Read more

Creates a value from an iterator. Read more

The type of the elements being iterated over.

Which kind of iterator are we turning this into?

Creates an iterator from a value. Read more

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Performs the conversion.

Performs the conversion.

Should always be Self

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.