pub struct TryCmdLoaders(/* private fields */);
Expand description

Mapping of file extension to function that can load it.

Methods from Deref<Target = BTreeMap<OsString, fn(_: &Path) -> Result<TryCmd, Error>>>§

1.0.0 · source

pub fn clear(&mut self)

Clears the map, removing all elements.

Examples
use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(1, "a");
a.clear();
assert!(a.is_empty());
1.0.0 · source

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 std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
assert_eq!(map.get(&1), Some(&"a"));
assert_eq!(map.get(&2), None);
1.40.0 · source

pub fn get_key_value<Q>(&self, k: &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 std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
assert_eq!(map.get_key_value(&1), Some((&1, &"a")));
assert_eq!(map.get_key_value(&2), None);
1.66.0 · source

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

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

Examples
use std::collections::BTreeMap;

let mut map = BTreeMap::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")));
1.66.0 · source

pub fn first_entry(&mut self) -> Option<OccupiedEntry<'_, K, V, A>>where K: Ord,

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 std::collections::BTreeMap;

let mut map = BTreeMap::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");
1.66.0 · source

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 std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
map.insert(2, "b");
while let Some((key, _val)) = map.pop_first() {
    assert!(map.iter().all(|(k, _v)| *k > key));
}
assert!(map.is_empty());
1.66.0 · source

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

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

Examples
use std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "b");
map.insert(2, "a");
assert_eq!(map.last_key_value(), Some((&2, &"a")));
1.66.0 · source

pub fn last_entry(&mut self) -> Option<OccupiedEntry<'_, K, V, A>>where K: Ord,

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 std::collections::BTreeMap;

let mut map = BTreeMap::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");
1.66.0 · source

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 std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
map.insert(2, "b");
while let Some((key, _val)) = map.pop_last() {
    assert!(map.iter().all(|(k, _v)| *k < key));
}
assert!(map.is_empty());
1.0.0 · source

pub fn contains_key<Q>(&self, key: &Q) -> boolwhere 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 std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
assert_eq!(map.contains_key(&1), true);
assert_eq!(map.contains_key(&2), false);
1.0.0 · source

pub fn get_mut<Q>(&mut self, key: &Q) -> Option<&mut V>where K: Borrow<Q> + Ord, Q: Ord + ?Sized,

Returns a mutable 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 std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
if let Some(x) = map.get_mut(&1) {
    *x = "b";
}
assert_eq!(map[&1], "b");
1.0.0 · source

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

Inserts 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, and the old value is returned. The key is not updated, though; this matters for types that can be == without being identical. See the module-level documentation for more.

Examples
use std::collections::BTreeMap;

let mut map = BTreeMap::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");
source

pub fn try_insert( &mut self, key: K, value: V ) -> Result<&mut V, OccupiedError<'_, K, V, A>>where K: Ord,

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

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.

Examples
#![feature(map_try_insert)]

use std::collections::BTreeMap;

let mut map = BTreeMap::new();
assert_eq!(map.try_insert(37, "a").unwrap(), &"a");

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

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 std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
assert_eq!(map.remove(&1), Some("a"));
assert_eq!(map.remove(&1), None);
1.45.0 · source

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 std::collections::BTreeMap;

let mut map = BTreeMap::new();
map.insert(1, "a");
assert_eq!(map.remove_entry(&1), Some((1, "a")));
assert_eq!(map.remove_entry(&1), None);
1.53.0 · source

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) for which f(&k, &mut v) returns false. The elements are visited in ascending key order.

Examples
use std::collections::BTreeMap;

let mut map: BTreeMap<i32, i32> = (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)]));
1.11.0 · source

pub fn append(&mut self, other: &mut BTreeMap<K, V, A>)where K: Ord, A: Clone,

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

If a key from other is already present in self, the respective value from self will be overwritten with the respective value from other.

Examples
use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c"); // Note: Key (3) also present in b.

let mut b = BTreeMap::new();
b.insert(3, "d"); // Note: Key (3) also present in a.
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"); // Note: "c" has been overwritten.
assert_eq!(a[&4], "e");
assert_eq!(a[&5], "f");
1.17.0 · source

pub fn range<T, R>(&self, range: R) -> Range<'_, K, V>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
use std::collections::BTreeMap;
use std::ops::Bound::Included;

let mut map = BTreeMap::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());
1.17.0 · source

pub fn range_mut<T, R>(&mut self, range: R) -> RangeMut<'_, K, V>where T: Ord + ?Sized, K: Borrow<T> + Ord, R: RangeBounds<T>,

Constructs a mutable 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
use std::collections::BTreeMap;

let mut map: BTreeMap<&str, i32> =
    [("Alice", 0), ("Bob", 0), ("Carol", 0), ("Cheryl", 0)].into();
for (_, balance) in map.range_mut("B".."Cheryl") {
    *balance += 100;
}
for (name, balance) in &map {
    println!("{name} => {balance}");
}
1.0.0 · source

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

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

Examples
use std::collections::BTreeMap;

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

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

assert_eq!(count["a"], 3);
assert_eq!(count["b"], 2);
assert_eq!(count["c"], 1);
1.11.0 · source

pub fn split_off<Q>(&mut self, key: &Q) -> BTreeMap<K, V, A>where Q: Ord + ?Sized, K: Borrow<Q> + Ord, A: Clone,

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

Examples
use std::collections::BTreeMap;

let mut a = BTreeMap::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");
source

pub fn extract_if<F>(&mut self, pred: F) -> ExtractIf<'_, K, V, F, A>where K: Ord, F: FnMut(&K, &mut V) -> bool,

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

Creates an iterator that visits all elements (key-value pairs) in ascending key order and uses a closure to determine if an element should be removed. If the closure returns true, the element is removed from the map and yielded. If the closure returns false, or panics, the element remains in the map and will not be yielded.

The iterator also lets you mutate the value of each element in the closure, regardless of whether you choose to keep or remove it.

If the returned ExtractIf is not exhausted, e.g. because it is dropped without iterating or the iteration short-circuits, then the remaining elements will be retained. Use retain with a negated predicate if you do not need the returned iterator.

Examples

Splitting a map into even and odd keys, reusing the original map:

#![feature(btree_extract_if)]
use std::collections::BTreeMap;

let mut map: BTreeMap<i32, i32> = (0..8).map(|x| (x, x)).collect();
let evens: BTreeMap<_, _> = map.extract_if(|k, _v| k % 2 == 0).collect();
let odds = map;
assert_eq!(evens.keys().copied().collect::<Vec<_>>(), [0, 2, 4, 6]);
assert_eq!(odds.keys().copied().collect::<Vec<_>>(), [1, 3, 5, 7]);
1.0.0 · source

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

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

Examples
use std::collections::BTreeMap;

let mut map = BTreeMap::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"));
1.0.0 · source

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

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

Examples
use std::collections::BTreeMap;

let mut map = BTreeMap::from([
   ("a", 1),
   ("b", 2),
   ("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;
    }
}
1.0.0 · source

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

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

Examples
use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(2, "b");
a.insert(1, "a");

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

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

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

Examples
use std::collections::BTreeMap;

let mut a = BTreeMap::new();
a.insert(1, "hello");
a.insert(2, "goodbye");

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

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

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

Examples
use std::collections::BTreeMap;

let mut a = BTreeMap::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!")]);
1.0.0 · source

pub fn len(&self) -> usize

Returns the number of elements in the map.

Examples
use std::collections::BTreeMap;

let mut a = BTreeMap::new();
assert_eq!(a.len(), 0);
a.insert(1, "a");
assert_eq!(a.len(), 1);
1.0.0 · source

pub fn is_empty(&self) -> bool

Returns true if the map contains no elements.

Examples
use std::collections::BTreeMap;

let mut a = BTreeMap::new();
assert!(a.is_empty());
a.insert(1, "a");
assert!(!a.is_empty());
source

pub fn lower_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, K, V>where K: Borrow<Q> + Ord, Q: Ord,

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

Returns a Cursor pointing at the first element that is above the given bound.

If no such element exists then a cursor pointing at the “ghost” non-element is returned.

Passing Bound::Unbounded will return a cursor pointing at the first element of the map.

Examples
#![feature(btree_cursors)]

use std::collections::BTreeMap;
use std::ops::Bound;

let mut a = BTreeMap::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");
a.insert(4, "c");
let cursor = a.lower_bound(Bound::Included(&2));
assert_eq!(cursor.key(), Some(&2));
let cursor = a.lower_bound(Bound::Excluded(&2));
assert_eq!(cursor.key(), Some(&3));
source

pub fn lower_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, K, V, A>where K: Borrow<Q> + Ord, Q: Ord,

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

Returns a CursorMut pointing at the first element that is above the given bound.

If no such element exists then a cursor pointing at the “ghost” non-element is returned.

Passing Bound::Unbounded will return a cursor pointing at the first element of the map.

Examples
#![feature(btree_cursors)]

use std::collections::BTreeMap;
use std::ops::Bound;

let mut a = BTreeMap::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");
a.insert(4, "c");
let cursor = a.lower_bound_mut(Bound::Included(&2));
assert_eq!(cursor.key(), Some(&2));
let cursor = a.lower_bound_mut(Bound::Excluded(&2));
assert_eq!(cursor.key(), Some(&3));
source

pub fn upper_bound<Q>(&self, bound: Bound<&Q>) -> Cursor<'_, K, V>where K: Borrow<Q> + Ord, Q: Ord,

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

Returns a Cursor pointing at the last element that is below the given bound.

If no such element exists then a cursor pointing at the “ghost” non-element is returned.

Passing Bound::Unbounded will return a cursor pointing at the last element of the map.

Examples
#![feature(btree_cursors)]

use std::collections::BTreeMap;
use std::ops::Bound;

let mut a = BTreeMap::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");
a.insert(4, "c");
let cursor = a.upper_bound(Bound::Included(&3));
assert_eq!(cursor.key(), Some(&3));
let cursor = a.upper_bound(Bound::Excluded(&3));
assert_eq!(cursor.key(), Some(&2));
source

pub fn upper_bound_mut<Q>(&mut self, bound: Bound<&Q>) -> CursorMut<'_, K, V, A>where K: Borrow<Q> + Ord, Q: Ord,

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

Returns a CursorMut pointing at the last element that is below the given bound.

If no such element exists then a cursor pointing at the “ghost” non-element is returned.

Passing Bound::Unbounded will return a cursor pointing at the last element of the map.

Examples
#![feature(btree_cursors)]

use std::collections::BTreeMap;
use std::ops::Bound;

let mut a = BTreeMap::new();
a.insert(1, "a");
a.insert(2, "b");
a.insert(3, "c");
a.insert(4, "c");
let cursor = a.upper_bound_mut(Bound::Included(&3));
assert_eq!(cursor.key(), Some(&3));
let cursor = a.upper_bound_mut(Bound::Excluded(&3));
assert_eq!(cursor.key(), Some(&2));

Trait Implementations§

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impl Clone for TryCmdLoaders

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fn clone(&self) -> TryCmdLoaders

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
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impl Debug for TryCmdLoaders

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

Formats the value using the given formatter. Read more
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impl Default for TryCmdLoaders

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fn default() -> Self

Returns the “default value” for a type. Read more
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impl Deref for TryCmdLoaders

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type Target = BTreeMap<OsString, fn(_: &Path) -> Result<TryCmd, Error>>

The resulting type after dereferencing.
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fn deref(&self) -> &Self::Target

Dereferences the value.
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impl DerefMut for TryCmdLoaders

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fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

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Blanket Implementations§

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> DynClone for Twhere T: Clone,

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fn __clone_box(&self, _: Private) -> *mut ()

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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> Pointable for T

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const ALIGN: usize = _

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> ToOwned for Twhere T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.