Struct slotmap::Key

pub struct Key { /* fields omitted */ }

Key used to access stored values in a slot map.

Do not use a key from one slot map in another. The behavior is safe but non-sensical (and might panic in case of out-of-bounds). Keys implement Ord so they can be used in e.g. BTreeMap but their order is arbitrary.

Methods

impl Key

pub fn null() -> Self

Creates a new key that is always invalid and distinct from any non-null key. A null key can only be created through this method, or default initialization of Key.

A null key is always invalid, but an invalid key (that is, a key that has been removed from the slot map) does not become a null key. A null is safe to use with any safe method of any slot map instance.

Examples

let mut sm = SlotMap::<i32>::new();
let nk = Key::null();
assert!(nk.is_null());
assert_eq!(sm.get(nk), None);

pub fn is_null(self) -> bool

Checks if a key is null. There is only a single null key, that is a.is_null() && b.is_null() implies a == b.

Examples

let a = Key::null();
let b = Key::default();
assert_eq!(a, b);

Trait Implementations

impl<T: Slottable> Index<Key> for SlotMap<T>

type Output = T

The returned type after indexing.

fn index(&self, key: Key) -> &T

Performs the indexing (container[index]) operation.

impl<T: Slottable> IndexMut<Key> for SlotMap<T>

fn index_mut(&mut self, key: Key) -> &mut T

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

impl<T> Index<Key> for DenseSlotMap<T>

type Output = T

The returned type after indexing.

fn index(&self, key: Key) -> &T

Performs the indexing (container[index]) operation.

impl<T> IndexMut<Key> for DenseSlotMap<T>

fn index_mut(&mut self, key: Key) -> &mut T

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

impl Debug for Key

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

Formats the value using the given formatter.

impl Clone for Key

fn clone(&self) -> Key

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Key

impl PartialEq for Key

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

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

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

This method tests for !=.

impl Eq for Key

impl PartialOrd for Key

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

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

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

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

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

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

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

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

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

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

impl Ord for Key

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

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

impl Hash for Key

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 Default for Key

fn default() -> Self

Returns the "default value" for a type.