Struct slotmap::hop::HopSlotMap[][src]

pub struct HopSlotMap<K: Key, V: Slottable> { /* fields omitted */ }
Expand description

Hop slot map, storage with stable unique keys.

See crate documentation for more details.

Implementations

Constructs a new, empty HopSlotMap.

Examples

let mut sm: HopSlotMap<_, i32> = HopSlotMap::new();

Creates an empty HopSlotMap with the given capacity.

The slot map will not reallocate until it holds at least capacity elements.

Examples

let mut sm: HopSlotMap<_, i32> = HopSlotMap::with_capacity(10);

Constructs a new, empty HopSlotMap with a custom key type.

Examples

new_key_type! {
    struct PositionKey;
}
let mut positions: HopSlotMap<PositionKey, i32> = HopSlotMap::with_key();

Creates an empty HopSlotMap with the given capacity and a custom key type.

The slot map will not reallocate until it holds at least capacity elements.

Examples

new_key_type! {
    struct MessageKey;
}
let mut messages = HopSlotMap::with_capacity_and_key(3);
let welcome: MessageKey = messages.insert("Welcome");
let good_day = messages.insert("Good day");
let hello = messages.insert("Hello");

Returns the number of elements in the slot map.

Examples

let mut sm = HopSlotMap::with_capacity(10);
sm.insert("len() counts actual elements, not capacity");
let key = sm.insert("removed elements don't count either");
sm.remove(key);
assert_eq!(sm.len(), 1);

Returns if the slot map is empty.

Examples

let mut sm = HopSlotMap::new();
let key = sm.insert("dummy");
assert_eq!(sm.is_empty(), false);
sm.remove(key);
assert_eq!(sm.is_empty(), true);

Returns the number of elements the HopSlotMap can hold without reallocating.

Examples

let sm: HopSlotMap<_, f64> = HopSlotMap::with_capacity(10);
assert_eq!(sm.capacity(), 10);

Reserves capacity for at least additional more elements to be inserted in the HopSlotMap. The collection may reserve more space to avoid frequent reallocations.

Panics

Panics if the new allocation size overflows usize.

Examples

let mut sm = HopSlotMap::new();
sm.insert("foo");
sm.reserve(32);
assert!(sm.capacity() >= 33);

Returns true if the slot map contains key.

Examples

let mut sm = HopSlotMap::new();
let key = sm.insert(42);
assert_eq!(sm.contains_key(key), true);
sm.remove(key);
assert_eq!(sm.contains_key(key), false);

Inserts a value into the slot map. Returns a unique key that can be used to access this value.

Panics

Panics if the number of elements in the slot map equals 232 - 2.

Examples

let mut sm = HopSlotMap::new();
let key = sm.insert(42);
assert_eq!(sm[key], 42);

Inserts a value given by f into the slot map. The key where the value will be stored is passed into f. This is useful to store values that contain their own key.

Panics

Panics if the number of elements in the slot map equals 232 - 2.

Examples

let mut sm = HopSlotMap::new();
let key = sm.insert_with_key(|k| (k, 20));
assert_eq!(sm[key], (key, 20));

Removes a key from the slot map, returning the value at the key if the key was not previously removed.

Examples

let mut sm = HopSlotMap::new();
let key = sm.insert(42);
assert_eq!(sm.remove(key), Some(42));
assert_eq!(sm.remove(key), None);

Retains only the elements specified by the predicate.

In other words, remove all key-value pairs (k, v) such that f(k, &mut v) returns false. This method invalidates any removed keys.

Examples

let mut sm = HopSlotMap::new();

let k1 = sm.insert(0);
let k2 = sm.insert(1);
let k3 = sm.insert(2);

sm.retain(|key, val| key == k1 || *val == 1);

assert!(sm.contains_key(k1));
assert!(sm.contains_key(k2));
assert!(!sm.contains_key(k3));

assert_eq!(2, sm.len());

Clears the slot map. Keeps the allocated memory for reuse.

Examples

let mut sm = HopSlotMap::new();
for i in 0..10 {
    sm.insert(i);
}
assert_eq!(sm.len(), 10);
sm.clear();
assert_eq!(sm.len(), 0);

Clears the slot map, returning all key-value pairs in arbitrary order as an iterator. Keeps the allocated memory for reuse.

Even if the iterator is not (fully) consumed, when it goes out of scope all remaining elements are cleared.

Examples

let mut sm = HopSlotMap::new();
let k = sm.insert(0);
let v: Vec<_> = sm.drain().collect();
assert_eq!(sm.len(), 0);
assert_eq!(v, vec![(k, 0)]);

Returns a reference to the value corresponding to the key.

Examples

let mut sm = HopSlotMap::new();
let key = sm.insert("bar");
assert_eq!(sm.get(key), Some(&"bar"));
sm.remove(key);
assert_eq!(sm.get(key), None);

Returns a reference to the value corresponding to the key without version or bounds checking.

Safety

This should only be used if contains_key(key) is true. Otherwise it is dangerous undefined behavior.

Examples

let mut sm = HopSlotMap::new();
let key = sm.insert("bar");
assert_eq!(unsafe { sm.get_unchecked(key) }, &"bar");
sm.remove(key);
// sm.get_unchecked(key) is now dangerous!

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

Examples

let mut sm = HopSlotMap::new();
let key = sm.insert(3.5);
if let Some(x) = sm.get_mut(key) {
    *x += 3.0;
}
assert_eq!(sm[key], 6.5);

Returns a mutable reference to the value corresponding to the key without version or bounds checking.

Safety

This should only be used if contains_key(key) is true. Otherwise it is dangerous undefined behavior.

Examples

let mut sm = HopSlotMap::new();
let key = sm.insert("foo");
unsafe { *sm.get_unchecked_mut(key) = "bar" };
assert_eq!(sm[key], "bar");
sm.remove(key);
// sm.get_unchecked_mut(key) is now dangerous!

An iterator visiting all key-value pairs in arbitrary order. The iterator element type is (K, &'a V).

Examples

let mut sm = HopSlotMap::new();
let k0 = sm.insert(0);
let k1 = sm.insert(1);
let k2 = sm.insert(2);

for (k, v) in sm.iter() {
    println!("key: {:?}, val: {}", k, v);
}

An iterator visiting all key-value pairs in arbitrary order, with mutable references to the values. The iterator element type is (K, &'a mut V).

Examples

let mut sm = HopSlotMap::new();
let k0 = sm.insert(10);
let k1 = sm.insert(20);
let k2 = sm.insert(30);

for (k, v) in sm.iter_mut() {
    if k != k1 {
        *v *= -1;
    }
}

assert_eq!(sm[k0], -10);
assert_eq!(sm[k1], 20);
assert_eq!(sm[k2], -30);

An iterator visiting all keys in arbitrary order. The iterator element type is K.

Examples

let mut sm = HopSlotMap::new();
let k0 = sm.insert(10);
let k1 = sm.insert(20);
let k2 = sm.insert(30);
let keys: HashSet<_> = sm.keys().collect();
let check: HashSet<_> = vec![k0, k1, k2].into_iter().collect();
assert_eq!(keys, check);

An iterator visiting all values in arbitrary order. The iterator element type is &'a V.

Examples

let mut sm = HopSlotMap::new();
let k0 = sm.insert(10);
let k1 = sm.insert(20);
let k2 = sm.insert(30);
let values: HashSet<_> = sm.values().collect();
let check: HashSet<_> = vec![&10, &20, &30].into_iter().collect();
assert_eq!(values, check);

An iterator visiting all values mutably in arbitrary order. The iterator element type is &'a mut V.

Examples

let mut sm = HopSlotMap::new();
sm.insert(1);
sm.insert(2);
sm.insert(3);
sm.values_mut().for_each(|n| { *n *= 3 });
let values: HashSet<_> = sm.into_iter().map(|(_k, v)| v).collect();
let check: HashSet<_> = vec![3, 6, 9].into_iter().collect();
assert_eq!(values, check);

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

The returned type after indexing.

Performs the indexing (container[index]) operation. Read more

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

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

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

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.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

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

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

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.