Struct enum_map::EnumMap

pub struct EnumMap<K: Internal<V>, V> { /* fields omitted */ }

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(EnumMap)] from enum_map_derive crate.

Additionally, bool and u8 automatically derives from EnumMap. 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

extern crate enum_map;
#[macro_use]
extern crate enum_map_derive;

use enum_map::EnumMap;

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

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

Methods

impl<K: Internal<V>, V: Default> EnumMap<K, V> where
    K::Array: Default, 

fn new() -> Self

Creates an enum map with default values.

extern crate enum_map;
#[macro_use]
extern crate enum_map_derive;

use enum_map::EnumMap;

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

fn main() {
    let enum_map = EnumMap::<_, i32>::new();
    assert_eq!(enum_map[Example::A], 0);
}

impl<K: Internal<V>, V> EnumMap<K, V>

fn len(&self) -> usize

Returns number of elements in enum map.

fn is_empty(&self) -> bool

Returns whether the enum variant set is empty.

This isn't particularly useful, as there is no real reason to use enum map for enums without variants. However, it is provided for consistency with data structures providing len method (and I will admit, to avoid clippy warnings).

Examples

extern crate enum_map;
#[macro_use]
extern crate enum_map_derive;

use enum_map::EnumMap;

#[derive(EnumMap)]
enum Void {}

#[derive(EnumMap)]
enum SingleVariant {
    Variant,
}

fn main() {
    assert_eq!(EnumMap::<Void, ()>::new().is_empty(), true);
    assert_eq!(EnumMap::<SingleVariant, ()>::new().is_empty(), false);
}

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

Returns an iterator over enum map.

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

Returns a mutable iterator over enum map.

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

Swaps two indexes.

Examples

#[macro_use]
extern crate enum_map;

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

Trait Implementations

impl<K: Internal<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: Internal<V>, V> Copy for EnumMap<K, V> where
    K::Array: Copy, 

impl<K: Internal<V>, V> PartialEq for EnumMap<K, V> where
    K::Array: PartialEq, 

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 !=.

impl<K: Internal<V>, V> Eq for EnumMap<K, V> where
    K::Array: Eq, 

impl<K: Internal<V>, V> Hash for EnumMap<K, V> where
    K::Array: Hash, 

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, 

Feeds a slice of this type into the given [Hasher].

impl<K: Internal<V>, V> Default for EnumMap<K, V> where
    K::Array: Default, 

fn default() -> Self

Returns the "default value" for a type.

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

type Output = V

The returned type after indexing

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

The method for the indexing (container[index]) operation

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

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

The method for the mutable indexing (container[index]) operation

impl<'a, K: Internal<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: Internal<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: Debug + Internal<V>, V: Debug> Debug for EnumMap<K, V> where
    K::Array: Debug, 

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<F: FnMut(K) -> V, K: Internal<V>, V> From<F> for EnumMap<K, V>

fn from(f: F) -> Self

Performs the conversion.