Struct SgMap

pub struct SgMap<K: Ord + Default, V: Default, const N: usize> { /* private fields */ }

Safe, fallible, embedded-friendly ordered map.

Fallible APIs

• try_insert
• try_append
• try_extend
• try_from_iter

TryFrom isn’t implemented because it would collide with the blanket implementation. See this open GitHub issue from 2018, this is a known Rust limitation that should be fixed via specialization in the future.

Attribution Note

The majority of API examples and descriptions are adapted or directly copied from the standard library’s BTreeMap. The goal is to offer embedded developers familiar, ergonomic APIs on resource constrained systems that otherwise don’t get the luxury of dynamic collections.

Implementations

impl<K: Ord + Default, V: Default, const N: usize> SgMap<K, V, N>

pub fn new() -> Self

Makes a new, empty SgMap.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();

map.insert(1, "a");

pub fn set_rebal_param( &mut self, alpha_num: f32, alpha_denom: f32, ) -> Result<(), SgError>

The original scapegoat tree paper’s alpha, a, can be chosen in the range 0.5 <= a < 1.0. a tunes how “aggressively” the data structure self-balances. It controls the trade-off between total rebuild time and maximum height guarantees.

• As a approaches 0.5, the tree will rebalance more often. Ths means slower insertions, but faster lookups and deletions.

  • An a equal to 0.5 means a tree that always maintains a perfect balance (e.g.“complete” binary tree, at all times).

• As a approaches 1.0, the tree will rebalance less often. This means quicker insertions, but slower lookups and deletions.

  • If a reached 1.0, it’d mean a tree that never rebalances.

Returns Err if 0.5 <= alpha_num / alpha_denom < 1.0 isn’t true (invalid a, out of range).

Examples

use scapegoat::SgMap;

let mut map: SgMap<isize, isize, 10> = SgMap::new();

// Set 2/3, e.g. `a = 0.666...` (it's default value).
assert!(map.set_rebal_param(2.0, 3.0).is_ok());

pub fn rebal_param(&self) -> (f32, f32)

Get the current rebalance parameter, alpha, as a tuple of (alpha_numerator, alpha_denominator). See the corresponding setter method for more details.

Examples

use scapegoat::SgMap;

let mut map: SgMap<isize, isize, 10> = SgMap::new();

// Set 2/3, e.g. `a = 0.666...` (it's default value).
assert!(map.set_rebal_param(2.0, 3.0).is_ok());

// Get the currently set value
assert_eq!(map.rebal_param(), (2.0, 3.0));

pub fn capacity(&self) -> usize

Total capacity, e.g. maximum number of map pairs.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<usize, &str, 10>::new();

assert!(map.capacity() == 10);

pub fn keys(&self) -> Keys<'_, K, V, N>

Gets an iterator over the keys of the map, in sorted order.

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 10>::new();
a.insert(2, "b");
a.insert(1, "a");

let keys: Vec<_> = a.keys().cloned().collect();
assert_eq!(keys, [1, 2]);

pub fn into_keys(self) -> IntoKeys<K, V, N>

Creates a consuming iterator visiting all the keys, in sorted order. The map cannot be used after calling this. The iterator element type is K.

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 10>::new();
a.insert(2, "b");
a.insert(1, "a");

let keys: Vec<i32> = a.into_keys().collect();
assert_eq!(keys, [1, 2]);

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

Gets an iterator over the values of the map, in order by key.

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 10>::new();
a.insert(1, "hello");
a.insert(2, "goodbye");

let values: Vec<&str> = a.values().cloned().collect();
assert_eq!(values, ["hello", "goodbye"]);

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

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

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 10>::new();
a.insert(1, "hello");
a.insert(2, "goodbye");

let values: Vec<&str> = a.into_values().collect();
assert_eq!(values, ["hello", "goodbye"]);

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

Gets a mutable iterator over the values of the map, in order by key.

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 10>::new();
a.insert(1, String::from("hello"));
a.insert(2, String::from("goodbye"));

for value in a.values_mut() {
    value.push_str("!");
}

let values: Vec<String> = a.values().cloned().collect();
assert_eq!(values, [String::from("hello!"),
                    String::from("goodbye!")]);

pub fn append(&mut self, other: &mut SgMap<K, V, N>)

Moves all elements from other into self, leaving other empty.

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 10>::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");

let mut b = SgMap::<_, _, 10>::new();
b.insert(3, "d");
b.insert(4, "e");
b.insert(5, "f");

a.append(&mut b);

assert_eq!(a.len(), 5);
assert_eq!(b.len(), 0);

assert_eq!(a[&1], "a");
assert_eq!(a[&2], "b");
assert_eq!(a[&3], "d");
assert_eq!(a[&4], "e");
assert_eq!(a[&5], "f");

pub fn try_append(&mut self, other: &mut SgMap<K, V, N>) -> Result<(), SgError>

Attempts to move all elements from other into self, leaving other empty.

Examples

use core::iter::FromIterator;
use scapegoat::{SgMap, SgError};

let mut a = SgMap::<_, _, 10>::new();
a.try_insert(1, "a").is_ok();
a.try_insert(2, "b").is_ok();
a.try_insert(3, "c").is_ok();

let mut b = SgMap::<_, _, 10>::new();
b.try_insert(3, "d").is_ok(); // Overwrite previous
b.try_insert(4, "e").is_ok();
b.try_insert(5, "f").is_ok();

// Successful append
assert!(a.try_append(&mut b).is_ok());

// Elements moved
assert_eq!(a.len(), 5);
assert_eq!(b.len(), 0);

assert_eq!(a[&1], "a");
assert_eq!(a[&2], "b");
assert_eq!(a[&3], "d");
assert_eq!(a[&4], "e");
assert_eq!(a[&5], "f");

// Fill remaining capacity
let mut key = 6;
while a.len() < a.capacity() {
    assert!(a.try_insert(key, "filler").is_ok());
    key += 1;
}

// Full
assert!(a.is_full());

// More data
let mut c = SgMap::<_, _, 10>::from_iter([(11, "k"), (12, "l")]);
let mut d = SgMap::<_, _, 10>::from_iter([(1, "a2"), (2, "b2")]);

// Cannot append new pairs
assert_eq!(a.try_append(&mut c), Err(SgError::StackCapacityExceeded));

// Can still replace existing pairs
assert!(a.try_append(&mut d).is_ok());

pub fn insert(&mut self, key: K, val: V) -> Option<V>

where K: Ord,

Insert a key-value pair into the map. If the map did not have this key present, None is returned. If the map did have this key present, the value is updated, the old value is returned, and the key is updated. This accommodates types that can be == without being identical.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
assert_eq!(map.insert(37, "a"), None);
assert_eq!(map.is_empty(), false);

map.insert(37, "b");
assert_eq!(map.insert(37, "c"), Some("b"));
assert_eq!(map[&37], "c");

pub fn try_insert(&mut self, key: K, val: V) -> Result<Option<V>, SgError>

where K: Ord,

Insert a key-value pair into the map. Returns Err if the operation can’t be completed, else the Ok contains:

• None if the map did not have this key present.
• The old value if the map did have this key present (both the value and key are updated, this accommodates types that can be == without being identical).

Warning

Unlike other APIs in this crate, the semantics and return type of this API are NOT the same as BTreeMap’s nightly try_insert. For an equivalent, use try_insert_std.

Examples

use scapegoat::{SgMap, SgError};

let mut map = SgMap::<_, _, 10>::new();

// Add a new pair
assert_eq!(map.try_insert(37, "a"), Ok(None));
assert_eq!(map.is_empty(), false);

// Replace existing pair
map.insert(37, "b");
assert_eq!(map.try_insert(37, "c"), Ok(Some("b")));
assert_eq!(map[&37], "c");

// Fill remaining capacity
let mut key = 38;
while map.len() < map.capacity() {
    assert!(map.try_insert(key, "filler").is_ok());
    key += 1;
}

// Full
assert!(map.is_full());

// Cannot insert new pair
assert_eq!(map.try_insert(key, "out of bounds"), Err(SgError::StackCapacityExceeded));

// Can still replace existing pair
assert_eq!(map.try_insert(key - 1, "overwrite filler"), Ok(Some("filler")));

pub fn try_insert_std( &mut self, key: K, value: V, ) -> Result<&mut V, OccupiedError<'_, K, V, N>>

where K: Ord,

Tries to insert a key-value pair into the map, and returns a mutable reference to the value in the entry.

If the map already had this key present, nothing is updated, and an error containing the occupied entry and the value is returned.

Warning

The semantics and return type of this API match BTreeMap’s nightly try_insert, NOT the other try_* APIs in this crate. For a fallible insert, use try_insert.

Examples

Basic usage:

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
assert_eq!(map.try_insert_std(37, "a").unwrap(), &"a");

let err = map.try_insert_std(37, "b").unwrap_err();
assert_eq!(err.entry.key(), &37);
assert_eq!(err.entry.get(), &"a");
assert_eq!(err.value, "b");

pub fn try_extend<I: ExactSizeIterator + IntoIterator<Item = (K, V)>>( &mut self, iter: I, ) -> Result<(), SgError>

Attempt to extend a collection with the contents of an iterator.

Examples

use core::iter::FromIterator;
use scapegoat::{SgMap, SgError};

let mut a = SgMap::<_, _, 2>::new();
let mut b = SgMap::<_, _, 3>::from_iter([(1, "a"), (2, "b"), (3, "c")]);
let mut c = SgMap::<_, _, 2>::from_iter([(1, "a"), (2, "b")]);

// Too big
assert_eq!(a.try_extend(b.into_iter()), Err(SgError::StackCapacityExceeded));

// Fits
assert!(a.try_extend(c.into_iter()).is_ok());

Note

There is no TryExtend trait in core/std.

pub fn try_from_iter<I: ExactSizeIterator + IntoIterator<Item = (K, V)>>( iter: I, ) -> Result<Self, SgError>

Attempt conversion from an iterator. Will fail if iterator length exceeds u16::MAX.

Examples

use scapegoat::{SgMap, SgError};

const CAPACITY_1: usize = 1_000;
let vec: Vec<(usize, usize)> = (0..CAPACITY_1).map(|n|(n, n)).collect();
assert!(SgMap::<usize, usize, CAPACITY_1>::try_from_iter(vec.into_iter()).is_ok());

const CAPACITY_2: usize = (u16::MAX as usize) + 1;
let vec: Vec<(usize, usize)> = (0..CAPACITY_2).map(|n|(n, n)).collect();
assert_eq!(
    SgMap::<usize, usize, CAPACITY_2>::try_from_iter(vec.into_iter()),
    Err(SgError::MaximumCapacityExceeded)
);

Note

There is no TryFromIterator trait in core/std.

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

Gets an iterator over the entries of the map, sorted by key.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(3, "c");
map.insert(2, "b");
map.insert(1, "a");

for (key, value) in map.iter() {
    println!("{}: {}", key, value);
}

let (first_key, first_value) = map.iter().next().unwrap();
assert_eq!((*first_key, *first_value), (1, "a"));

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

Gets a mutable iterator over the entries of the map, sorted by key.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

// Add 10 to the value if the key isn't "a"
for (key, value) in map.iter_mut() {
    if key != &"a" {
        *value += 10;
    }
}

let (second_key, second_value) = map.iter().skip(1).next().unwrap();
assert_eq!((*second_key, *second_value), ("b", 12));

pub fn remove_entry<Q>(&mut self, key: &Q) -> Option<(K, V)>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Removes a key from the map, returning the stored key and value if the key was previously in the map.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "a");
assert_eq!(map.remove_entry(&1), Some((1, "a")));
assert_eq!(map.remove_entry(&1), None);

pub fn retain<F>(&mut self, f: F)

where K: Ord, F: FnMut(&K, &mut V) -> bool,

Retains only the elements specified by the predicate.

In other words, remove all pairs (k, v) such that f(&k, &mut v) returns false. The elements are visited in ascending key order.

Examples

use scapegoat::SgMap;

let mut map: SgMap<i32, i32, 10> = (0..8).map(|x| (x, x*10)).collect();
// Keep only the elements with even-numbered keys.
map.retain(|&k, _| k % 2 == 0);
assert!(map.into_iter().eq(vec![(0, 0), (2, 20), (4, 40), (6, 60)]));

pub fn split_off<Q>(&mut self, key: &Q) -> SgMap<K, V, N>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Splits the collection into two at the given key. Returns everything after the given key, including the key.

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 10>::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");
a.insert(17, "d");
a.insert(41, "e");

let b = a.split_off(&3);

assert_eq!(a.len(), 2);
assert_eq!(b.len(), 3);

assert_eq!(a[&1], "a");
assert_eq!(a[&2], "b");

assert_eq!(b[&3], "c");
assert_eq!(b[&17], "d");
assert_eq!(b[&41], "e");

pub fn remove<Q>(&mut self, key: &Q) -> Option<V>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Removes a key from the map, returning the value at the key if the key was previously in the map.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "a");
assert_eq!(map.remove(&1), Some("a"));
assert_eq!(map.remove(&1), None);

pub fn get_key_value<Q>(&self, key: &Q) -> Option<(&K, &V)>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Returns the key-value pair corresponding to the supplied key.

The supplied key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "a");
assert_eq!(map.get_key_value(&1), Some((&1, &"a")));
assert_eq!(map.get_key_value(&2), None);

pub fn get<Q>(&self, key: &Q) -> Option<&V>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Returns a reference to the value corresponding to the key.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "a");
assert_eq!(map.get(&1), Some(&"a"));
assert_eq!(map.get(&2), None);

pub fn get_mut<Q>(&mut self, key: &Q) -> Option<&mut V>

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "a");
if let Some(x) = map.get_mut(&1) {
    *x = "b";
}
assert_eq!(map[&1], "b");

pub fn clear(&mut self)

Clears the map, removing all elements.

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 10>::new();
a.insert(1, "a");
a.clear();
assert!(a.is_empty());

pub fn contains_key<Q>(&self, key: &Q) -> bool

where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Returns true if the map contains a value for the specified key.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "a");
assert_eq!(map.contains_key(&1), true);
assert_eq!(map.contains_key(&2), false);

pub fn is_empty(&self) -> bool

Returns true if the map contains no elements.

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 10>::new();
assert!(a.is_empty());
a.insert(1, "a");
assert!(!a.is_empty());

pub fn is_full(&self) -> bool

Returns true if the map’s capacity is filled.

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 2>::new();
a.insert(1, "a");
assert!(!a.is_full());
a.insert(2, "b");
assert!(a.is_full());

pub fn first_key_value(&self) -> Option<(&K, &V)>

where K: Ord,

Returns a reference to the first key-value pair in the map. The key in this pair is the minimum key in the map.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
assert_eq!(map.first_key_value(), None);
map.insert(1, "b");
map.insert(2, "a");
assert_eq!(map.first_key_value(), Some((&1, &"b")));

pub fn first_key(&self) -> Option<&K>

where K: Ord,

Returns a reference to the first/minium key in the map, if any.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
assert_eq!(map.first_key_value(), None);
map.insert(1, "b");
map.insert(2, "a");
assert_eq!(map.first_key(), Some(&1));

pub fn pop_first(&mut self) -> Option<(K, V)>

where K: Ord,

Removes and returns the first element in the map. The key of this element is the minimum key that was in the map.

Examples

Draining elements in ascending order, while keeping a usable map each iteration.

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "a");
map.insert(2, "b");
while let Some((key, _val)) = map.pop_first() {
    assert!((&map).into_iter().all(|(k, _v)| *k > key));
}
assert!(map.is_empty());

pub fn last_key_value(&self) -> Option<(&K, &V)>

where K: Ord,

Returns a reference to the last key-value pair in the map. The key in this pair is the maximum key in the map.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "b");
map.insert(2, "a");
assert_eq!(map.last_key_value(), Some((&2, &"a")));

pub fn last_key(&self) -> Option<&K>

where K: Ord,

Returns a reference to the last/maximum key in the map, if any.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "b");
map.insert(2, "a");
assert_eq!(map.last_key(), Some(&2));

pub fn pop_last(&mut self) -> Option<(K, V)>

where K: Ord,

Removes and returns the last element in the map. The key of this element is the maximum key that was in the map.

Examples

Draining elements in descending order, while keeping a usable map each iteration.

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "a");
map.insert(2, "b");
while let Some((key, _val)) = map.pop_last() {
    assert!((&map).into_iter().all(|(k, _v)| *k < key));
}
assert!(map.is_empty());

pub fn len(&self) -> usize

Returns the number of elements in the map.

Examples

use scapegoat::SgMap;

let mut a = SgMap::<_, _, 10>::new();
assert_eq!(a.len(), 0);
a.insert(1, "a");
assert_eq!(a.len(), 1);

pub fn entry(&mut self, key: K) -> Entry<'_, K, V, N>

Gets the given key’s corresponding entry in the map for in-place manipulation.

Examples

Basic usage:

use scapegoat::SgMap;

let mut count = SgMap::<&str, usize, 10>::new();

// count the number of occurrences of letters in the vec
for x in vec!["a", "b", "a", "c", "a", "b"] {
    *count.entry(x).or_insert(0) += 1;
}

assert_eq!(count["a"], 3);

pub fn first_entry(&mut self) -> Option<OccupiedEntry<'_, K, V, N>>

Returns the first entry in the map for in-place manipulation. The key of this entry is the minimum key in the map.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "a");
map.insert(2, "b");
if let Some(mut entry) = map.first_entry() {
    if *entry.key() > 0 {
        entry.insert("first");
    }
}
assert_eq!(*map.get(&1).unwrap(), "first");
assert_eq!(*map.get(&2).unwrap(), "b");

pub fn last_entry(&mut self) -> Option<OccupiedEntry<'_, K, V, N>>

Returns the last entry in the map for in-place manipulation. The key of this entry is the maximum key in the map.

Examples

use scapegoat::SgMap;

let mut map = SgMap::<_, _, 10>::new();
map.insert(1, "a");
map.insert(2, "b");
if let Some(mut entry) = map.last_entry() {
    if *entry.key() > 0 {
        entry.insert("last");
    }
}
assert_eq!(*map.get(&1).unwrap(), "a");
assert_eq!(*map.get(&2).unwrap(), "last");

pub fn range<T, R>(&self, range: R) -> Range<'_, K, V, N>

where T: Ord + ?Sized, K: Borrow<T> + Ord, R: RangeBounds<T>,

Constructs a double-ended iterator over a sub-range of elements in the map. The simplest way is to use the range syntax min..max, thus range(min..max) will yield elements from min (inclusive) to max (exclusive). The range may also be entered as (Bound<T>, Bound<T>), so for example range((Excluded(4), Included(10))) will yield a left-exclusive, right-inclusive range from 4 to 10.

Panics

Panics if range start > end. Panics if range start == end and both bounds are Excluded.

Examples

Basic usage:

use scapegoat::SgMap;
use core::ops::Bound::Included;

let mut map = SgMap::<_, _, 10>::new();
map.insert(3, "a");
map.insert(5, "b");
map.insert(8, "c");
for (&key, &value) in map.range((Included(&4), Included(&8))) {
    println!("{}: {}", key, value);
}
assert_eq!(Some((&5, &"b")), map.range(4..).next());

pub fn range_mut<T, R>(&mut self, range: R) -> RangeMut<'_, K, V, N>

where T: Ord + ?Sized, K: Borrow<T> + Ord, R: RangeBounds<T>,

Constructs a mutable single-ended iterator over a sub-range of elements in the map. The simplest way is to use the range syntax min..max, thus range(min..max) will yield elements from min (inclusive) to max (exclusive). The range may also be entered as (Bound<T>, Bound<T>), so for example range((Excluded(4), Included(10))) will yield a left-exclusive, right-inclusive range from 4 to 10.

Panics

Panics if range start > end. Panics if range start == end and both bounds are Excluded.

Examples

Basic usage:

use scapegoat::SgMap;

let mut map: SgMap<_, _, 10> = ["Alice", "Bob", "Carol", "Cheryl"]
    .iter()
    .map(|&s| (s, 0))
    .collect();
for (_, balance) in map.range_mut("B".."Cheryl") {
    *balance += 100;
}
for (name, balance) in &map {
    println!("{} => {}", name, balance);
}

assert_eq!(map["Alice"], 0);
assert_eq!(map["Bob"], 100);

Trait Implementations

impl<K: Clone + Ord + Default, V: Clone + Default, const N: usize> Clone for SgMap<K, V, N>

fn clone(&self) -> SgMap<K, V, N>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<K, V, const N: usize> Debug for SgMap<K, V, N>

where K: Ord + Debug + Default, V: Debug + Default,

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

Formats the value using the given formatter.

impl<K: Default + Ord + Default, V: Default + Default, const N: usize> Default for SgMap<K, V, N>

fn default() -> SgMap<K, V, N>

Returns the “default value” for a type.

impl<'a, K, V, const N: usize> Extend<(&'a K, &'a V)> for SgMap<K, V, N>

where K: Ord + Copy + Default, V: Copy + Default,

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, V: Default, const N: usize> Extend<(K, V)> for SgMap<K, V, N>

where K: Ord + Default,

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

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: Default, const N: usize> From<[(K, V); N]> for SgMap<K, V, N>

where K: Ord + Default,

fn from(arr: [(K, V); N]) -> Self

use scapegoat::SgMap;

let map1 = SgMap::from([(1, 2), (3, 4)]);
let map2: SgMap<_, _, 2> = [(1, 2), (3, 4)].into();
assert_eq!(map1, map2);

Warning

TryFrom isn’t implemented because it would collide with the blanket implementation. See this open GitHub issue from 2018, this is a known Rust limitation that should be fixed via specialization in the future.

impl<K, V: Default, const N: usize> FromIterator<(K, V)> for SgMap<K, V, N>

where K: Ord + Default,

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

Creates a value from an iterator.

impl<K: Hash + Ord + Default, V: Hash + Default, const N: usize> Hash for SgMap<K, V, N>

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, V: Default, Q, const N: usize> Index<&Q> for SgMap<K, V, N>

where K: Borrow<Q> + Ord + Default, Q: Ord + ?Sized,

fn index(&self, key: &Q) -> &Self::Output

Returns a reference to the value corresponding to the supplied key.

Panics

Panics if the key is not present in the SgMap.

type Output = V

The returned type after indexing.

impl<'a, K: Ord + Default, V: Default, const N: usize> IntoIterator for &'a SgMap<K, V, N>

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

The type of the elements being iterated over.

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

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<K: Ord + Default, V: Default, const N: usize> IntoIterator for SgMap<K, V, N>

type Item = (K, V)

The type of the elements being iterated over.

type IntoIter = IntoIter<K, V, N>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<K: Ord + Ord + Default, V: Ord + Default, const N: usize> Ord for SgMap<K, V, N>

fn cmp(&self, other: &SgMap<K, V, N>) -> 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,

Restrict a value to a certain interval.

impl<K: PartialEq + Ord + Default, V: PartialEq + Default, const N: usize> PartialEq for SgMap<K, V, N>

fn eq(&self, other: &SgMap<K, V, N>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

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

impl<K: PartialOrd + Ord + Default, V: PartialOrd + Default, const N: usize> PartialOrd for SgMap<K, V, N>

fn partial_cmp(&self, other: &SgMap<K, V, N>) -> Option<Ordering>

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl<K: Eq + Ord + Default, V: Eq + Default, const N: usize> Eq for SgMap<K, V, N>

impl<K: Ord + Default, V: Default, const N: usize> StructuralPartialEq for SgMap<K, V, N>