Struct enum_map::EnumMap

pub struct EnumMap<K: EnumArray<V>, V> { /* private fields */ }

An enum mapping.

This internally uses an array which stores a value for each possible enum value. To work, it requires implementation of internal (private, although public due to macro limitations) trait which allows extracting information about an enum, which can be automatically generated using #[derive(Enum)] macro.

Additionally, bool and u8 automatically derives from Enum. While u8 is not technically an enum, it’s convenient to consider it like one. In particular, reverse-complement in benchmark game could be using u8 as an enum.

Examples

use enum_map::{enum_map, Enum, EnumMap};

#[derive(Enum)]
enum Example {
    A,
    B,
    C,
}

let mut map = EnumMap::default();
// new initializes map with default values
assert_eq!(map[Example::A], 0);
map[Example::A] = 3;
assert_eq!(map[Example::A], 3);

Implementations

impl<K: EnumArray<V>, V> EnumMap<K, V>

pub fn values(&self) -> Values<'_, V>

An iterator visiting all values. The iterator type is &V.

Examples

use enum_map::enum_map;

let map = enum_map! { false => 3, true => 4 };
let mut values = map.values();
assert_eq!(values.next(), Some(&3));
assert_eq!(values.next(), Some(&4));
assert_eq!(values.next(), None);

pub fn values_mut(&mut self) -> ValuesMut<'_, V>

An iterator visiting all values mutably. The iterator type is &mut V.

Examples

use enum_map::enum_map;

let mut map = enum_map! { _ => 2 };
for value in map.values_mut() {
    *value += 2;
}
assert_eq!(map[false], 4);
assert_eq!(map[true], 4);

pub fn into_values(self) -> IntoValues<K, V>

Creates a consuming iterator visiting all the values. The map cannot be used after calling this. The iterator element type is V.

Examples

use enum_map::enum_map;

let mut map = enum_map! { false => "hello", true => "goodbye" };
assert_eq!(map.into_values().collect::<Vec<_>>(), ["hello", "goodbye"]);

impl<K: EnumArray<V>, V: Default> EnumMap<K, V>

pub fn clear(&mut self)

Clear enum map with default values.

Examples

use enum_map::{Enum, EnumMap};

#[derive(Enum)]
enum Example {
    A,
    B,
}

let mut enum_map = EnumMap::<_, String>::default();
enum_map[Example::B] = "foo".into();
enum_map.clear();
assert_eq!(enum_map[Example::A], "");
assert_eq!(enum_map[Example::B], "");

impl<K: EnumArray<V>, V> EnumMap<K, V>

pub const fn from_array(array: K::Array) -> EnumMap<K, V>

Creates an enum map from array.

pub fn from_fn<F>(cb: F) -> Self

where F: FnMut(K) -> V,

Create an enum map, where each value is the returned value from cb using provided enum key.

use enum_map::{enum_map, Enum, EnumMap};

#[derive(Enum, PartialEq, Debug)]
enum Example {
    A,
    B,
}

let map = EnumMap::from_fn(|k| k == Example::A);
assert_eq!(map, enum_map! { Example::A => true, Example::B => false })

pub fn iter(&self) -> Iter<'_, K, V>

Returns an iterator over enum map.

The iteration order is deterministic, and when using Enum derive it will be the order in which enum variants are declared.

Examples

use enum_map::{enum_map, Enum};

#[derive(Enum, PartialEq)]
enum E {
    A,
    B,
    C,
}

let map = enum_map! { E::A => 1, E::B => 2, E::C => 3};
assert!(map.iter().eq([(E::A, &1), (E::B, &2), (E::C, &3)]));

pub fn iter_mut(&mut self) -> IterMut<'_, K, V>

Returns a mutable iterator over enum map.

pub const fn len(&self) -> usize

Returns number of elements in enum map.

pub fn swap(&mut self, a: K, b: K)

Swaps two indexes.

Examples

use enum_map::enum_map;

let mut map = enum_map! { false => 0, true => 1 };
map.swap(false, true);
assert_eq!(map[false], 1);
assert_eq!(map[true], 0);

pub fn into_array(self) -> K::Array

Consumes an enum map and returns the underlying array.

The order of elements is deterministic, and when using Enum derive it will be the order in which enum variants are declared.

Examples

use enum_map::{enum_map, Enum};

#[derive(Enum, PartialEq)]
enum E {
    A,
    B,
    C,
}

let map = enum_map! { E::A => 1, E::B => 2, E::C => 3};
assert_eq!(map.into_array(), [1, 2, 3]);

pub const fn as_array(&self) -> &K::Array

Returns a reference to the underlying array.

The order of elements is deterministic, and when using Enum derive it will be the order in which enum variants are declared.

Examples

use enum_map::{enum_map, Enum};

#[derive(Enum, PartialEq)]
enum E {
    A,
    B,
    C,
}

let map = enum_map! { E::A => 1, E::B => 2, E::C => 3};
assert_eq!(map.as_array(), &[1, 2, 3]);

pub fn as_mut_array(&mut self) -> &mut K::Array

Returns a mutable reference to the underlying array.

The order of elements is deterministic, and when using Enum derive it will be the order in which enum variants are declared.

Examples

use enum_map::{enum_map, Enum};

#[derive(Enum, PartialEq)]
enum E {
    A,
    B,
    C,
}

let mut map = enum_map! { E::A => 1, E::B => 2, E::C => 3};
map.as_mut_array()[1] = 42;
assert_eq!(map.as_array(), &[1, 42, 3]);

pub fn as_slice(&self) -> &[V]

Converts an enum map to a slice representing values.

The order of elements is deterministic, and when using Enum derive it will be the order in which enum variants are declared.

Examples

use enum_map::{enum_map, Enum};

#[derive(Enum, PartialEq)]
enum E {
    A,
    B,
    C,
}

let map = enum_map! { E::A => 1, E::B => 2, E::C => 3};
assert_eq!(map.as_slice(), &[1, 2, 3]);

pub fn as_mut_slice(&mut self) -> &mut [V]

Converts a mutable enum map to a mutable slice representing values.

pub fn map<F, T>(self, f: F) -> EnumMap<K, T>

where F: FnMut(K, V) -> T, K: EnumArray<T>,

Returns an enum map with function f applied to each element in order.

Examples

use enum_map::enum_map;

let a = enum_map! { false => 0, true => 1 };
let b = a.map(|_, x| f64::from(x) + 0.5);
assert_eq!(b, enum_map! { false => 0.5, true => 1.5 });

Trait Implementations

impl<'a, K: EnumArray<V>, V: Arbitrary<'a>> Arbitrary<'a> for EnumMap<K, V>

Requires crate feature "arbitrary"

fn arbitrary(u: &mut Unstructured<'a>) -> Result<EnumMap<K, V>>

Generate an arbitrary value of Self from the given unstructured data.

fn size_hint(depth: usize) -> (usize, Option<usize>)

Get a size hint for how many bytes out of an Unstructured this type needs to construct itself.

fn arbitrary_take_rest(u: Unstructured<'a>) -> Result<Self, Error>

Generate an arbitrary value of Self from the entirety of the given unstructured data.

impl<K: EnumArray<V>, V> Clone for EnumMap<K, V>

where K::Array: Clone,

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<K: EnumArray<V> + Debug, V: Debug> Debug for EnumMap<K, V>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<K: EnumArray<V>, V: Default> Default for EnumMap<K, V>

fn default() -> Self

Returns the “default value” for a type.

impl<'de, K, V> Deserialize<'de> for EnumMap<K, V>

where K: EnumArray<V> + EnumArray<Option<V>> + Deserialize<'de>, V: Deserialize<'de>,

Requires crate feature "serde"

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl<'a, K, V> Extend<(&'a K, &'a V)> for EnumMap<K, V>

where K: EnumArray<V> + Copy, V: Copy,

fn extend<I: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iter: I)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

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

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

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

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

impl<K: EnumArray<V>, V> Extend<(K, V)> for EnumMap<K, V>

fn extend<I: IntoIterator<Item = (K, V)>>(&mut self, iter: I)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

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

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

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

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

impl<K, V> FromIterator<(K, V)> for EnumMap<K, V>

where Self: Default, K: EnumArray<V>,

fn from_iter<I: IntoIterator<Item = (K, V)>>(iter: I) -> Self

Creates a value from an iterator.

impl<K: EnumArray<V>, V: Hash> Hash for EnumMap<K, V>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<K: EnumArray<V>, V> Index<K> for EnumMap<K, V>

type Output = V

The returned type after indexing.

fn index(&self, key: K) -> &V

Performs the indexing (container[index]) operation.

impl<K: EnumArray<V>, V> IndexMut<K> for EnumMap<K, V>

fn index_mut(&mut self, key: K) -> &mut V

Performs the mutable indexing (container[index]) operation.

impl<'a, K: EnumArray<V>, V> IntoIterator for &'a EnumMap<K, V>

type Item = (K, &'a V)

The type of the elements being iterated over.

type IntoIter = Iter<'a, K, V>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a, K: EnumArray<V>, V> IntoIterator for &'a mut EnumMap<K, V>

type Item = (K, &'a mut V)

The type of the elements being iterated over.

type IntoIter = IterMut<'a, K, V>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<K: EnumArray<V>, V> IntoIterator for EnumMap<K, V>

type Item = (K, V)

The type of the elements being iterated over.

type IntoIter = IntoIter<K, V>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<K: EnumArray<V>, V: Ord> Ord for EnumMap<K, V>

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl<K: EnumArray<V>, V: PartialEq> PartialEq for EnumMap<K, V>

fn eq(&self, other: &Self) -> bool

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

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<K: EnumArray<V>, V: PartialOrd> PartialOrd for EnumMap<K, V>

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<K: EnumArray<V> + Serialize, V: Serialize> Serialize for EnumMap<K, V>

Requires crate feature "serde"

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl<K: EnumArray<V>, V> Copy for EnumMap<K, V>

where K::Array: Copy,

impl<K: EnumArray<V>, V: Eq> Eq for EnumMap<K, V>