Expand description
An owning iterator over the entries of a BTreeMap
.
This struct
is created by the into_iter
method on BTreeMap
(provided by the IntoIterator
trait). See its documentation for more.
Trait Implementations
sourceimpl<K, V, A: Allocator> DoubleEndedIterator for IntoIter<K, V, A>
impl<K, V, A: Allocator> DoubleEndedIterator for IntoIter<K, V, A>
sourcefn next_back(&mut self) -> Option<(K, V)>
fn next_back(&mut self) -> Option<(K, V)>
Removes and returns an element from the end of the iterator. Read more
sourcefn advance_back_by(&mut self, n: usize) -> Result<(), usize>
fn advance_back_by(&mut self, n: usize) -> Result<(), usize>
Advances the iterator from the back by n
elements. Read more
1.37.0 · sourcefn nth_back(&mut self, n: usize) -> Option<Self::Item>
fn nth_back(&mut self, n: usize) -> Option<Self::Item>
Returns the n
th element from the end of the iterator. Read more
1.27.0 · sourcefn try_rfold<B, F, R>(&mut self, init: B, f: F) -> R where
F: FnMut(B, Self::Item) -> R,
R: Try<Output = B>,
fn try_rfold<B, F, R>(&mut self, init: B, f: F) -> R where
F: FnMut(B, Self::Item) -> R,
R: Try<Output = B>,
This is the reverse version of Iterator::try_fold()
: it takes
elements starting from the back of the iterator. Read more
sourceimpl<K, V, A: Allocator> ExactSizeIterator for IntoIter<K, V, A>
impl<K, V, A: Allocator> ExactSizeIterator for IntoIter<K, V, A>
sourceimpl<K, V, A: Allocator> Iterator for IntoIter<K, V, A>
impl<K, V, A: Allocator> Iterator for IntoIter<K, V, A>
sourcefn next(&mut self) -> Option<(K, V)>
fn next(&mut self) -> Option<(K, V)>
Advances the iterator and returns the next value. Read more
sourcefn size_hint(&self) -> (usize, Option<usize>)
fn size_hint(&self) -> (usize, Option<usize>)
Returns the bounds on the remaining length of the iterator. Read more
sourcefn count(self) -> usize
fn count(self) -> usize
Consumes the iterator, counting the number of iterations and returning it. Read more
sourcefn last(self) -> Option<Self::Item>
fn last(self) -> Option<Self::Item>
Consumes the iterator, returning the last element. Read more
sourcefn advance_by(&mut self, n: usize) -> Result<(), usize>
fn advance_by(&mut self, n: usize) -> Result<(), usize>
Advances the iterator by n
elements. Read more
sourcefn nth(&mut self, n: usize) -> Option<Self::Item>
fn nth(&mut self, n: usize) -> Option<Self::Item>
Returns the n
th element of the iterator. Read more
1.28.0 · sourcefn step_by(self, step: usize) -> StepBy<Self>
fn step_by(self, step: usize) -> StepBy<Self>
Creates an iterator starting at the same point, but stepping by the given amount at each iteration. Read more
sourcefn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter> where
U: IntoIterator<Item = Self::Item>,
fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter> where
U: IntoIterator<Item = Self::Item>,
Takes two iterators and creates a new iterator over both in sequence. Read more
sourcefn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter> where
U: IntoIterator,
fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter> where
U: IntoIterator,
‘Zips up’ two iterators into a single iterator of pairs. Read more
sourcefn intersperse(self, separator: Self::Item) -> Intersperse<Self> where
Self::Item: Clone,
fn intersperse(self, separator: Self::Item) -> Intersperse<Self> where
Self::Item: Clone,
Creates a new iterator which places a copy of separator
between adjacent
items of the original iterator. Read more
sourcefn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G> where
G: FnMut() -> Self::Item,
fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G> where
G: FnMut() -> Self::Item,
Creates a new iterator which places an item generated by separator
between adjacent items of the original iterator. Read more
sourcefn map<B, F>(self, f: F) -> Map<Self, F> where
F: FnMut(Self::Item) -> B,
fn map<B, F>(self, f: F) -> Map<Self, F> where
F: FnMut(Self::Item) -> B,
Takes a closure and creates an iterator which calls that closure on each element. Read more
1.21.0 · sourcefn for_each<F>(self, f: F) where
F: FnMut(Self::Item),
fn for_each<F>(self, f: F) where
F: FnMut(Self::Item),
Calls a closure on each element of an iterator. Read more
sourcefn filter<P>(self, predicate: P) -> Filter<Self, P> where
P: FnMut(&Self::Item) -> bool,
fn filter<P>(self, predicate: P) -> Filter<Self, P> where
P: FnMut(&Self::Item) -> bool,
Creates an iterator which uses a closure to determine if an element should be yielded. Read more
sourcefn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where
F: FnMut(Self::Item) -> Option<B>,
fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where
F: FnMut(Self::Item) -> Option<B>,
Creates an iterator that both filters and maps. Read more
sourcefn enumerate(self) -> Enumerate<Self>
fn enumerate(self) -> Enumerate<Self>
Creates an iterator which gives the current iteration count as well as the next value. Read more
sourcefn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where
P: FnMut(&Self::Item) -> bool,
fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where
P: FnMut(&Self::Item) -> bool,
sourcefn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where
P: FnMut(&Self::Item) -> bool,
fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where
P: FnMut(&Self::Item) -> bool,
Creates an iterator that yields elements based on a predicate. Read more
1.57.0 · sourcefn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P> where
P: FnMut(Self::Item) -> Option<B>,
fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P> where
P: FnMut(Self::Item) -> Option<B>,
Creates an iterator that both yields elements based on a predicate and maps. Read more
sourcefn skip(self, n: usize) -> Skip<Self>
fn skip(self, n: usize) -> Skip<Self>
Creates an iterator that skips the first n
elements. Read more
sourcefn take(self, n: usize) -> Take<Self>
fn take(self, n: usize) -> Take<Self>
Creates an iterator that yields the first n
elements, or fewer
if the underlying iterator ends sooner. Read more
sourcefn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where
F: FnMut(&mut St, Self::Item) -> Option<B>,
fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where
F: FnMut(&mut St, Self::Item) -> Option<B>,
sourcefn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
U: IntoIterator,
F: FnMut(Self::Item) -> U,
fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where
U: IntoIterator,
F: FnMut(Self::Item) -> U,
Creates an iterator that works like map, but flattens nested structure. Read more
1.29.0 · sourcefn flatten(self) -> Flatten<Self> where
Self::Item: IntoIterator,
fn flatten(self) -> Flatten<Self> where
Self::Item: IntoIterator,
Creates an iterator that flattens nested structure. Read more
sourcefn inspect<F>(self, f: F) -> Inspect<Self, F> where
F: FnMut(&Self::Item),
fn inspect<F>(self, f: F) -> Inspect<Self, F> where
F: FnMut(&Self::Item),
Does something with each element of an iterator, passing the value on. Read more
sourcefn collect<B>(self) -> B where
B: FromIterator<Self::Item>,
fn collect<B>(self) -> B where
B: FromIterator<Self::Item>,
Transforms an iterator into a collection. Read more
sourcefn try_collect<B>(
&mut self
) -> <<Self::Item as Try>::Residual as Residual<B>>::TryType where
B: FromIterator<<Self::Item as Try>::Output>,
Self::Item: Try,
<Self::Item as Try>::Residual: Residual<B>,
fn try_collect<B>(
&mut self
) -> <<Self::Item as Try>::Residual as Residual<B>>::TryType where
B: FromIterator<<Self::Item as Try>::Output>,
Self::Item: Try,
<Self::Item as Try>::Residual: Residual<B>,
Fallibly transforms an iterator into a collection, short circuiting if a failure is encountered. Read more
sourcefn collect_into<E>(self, collection: &mut E) -> &mut E where
E: Extend<Self::Item>,
fn collect_into<E>(self, collection: &mut E) -> &mut E where
E: Extend<Self::Item>,
Collects all the items from an iterator into a collection. Read more
sourcefn partition<B, F>(self, f: F) -> (B, B) where
B: Default + Extend<Self::Item>,
F: FnMut(&Self::Item) -> bool,
fn partition<B, F>(self, f: F) -> (B, B) where
B: Default + Extend<Self::Item>,
F: FnMut(&Self::Item) -> bool,
Consumes an iterator, creating two collections from it. Read more
sourcefn partition_in_place<'a, T, P>(self, predicate: P) -> usize where
T: 'a,
Self: DoubleEndedIterator<Item = &'a mut T>,
P: FnMut(&T) -> bool,
fn partition_in_place<'a, T, P>(self, predicate: P) -> usize where
T: 'a,
Self: DoubleEndedIterator<Item = &'a mut T>,
P: FnMut(&T) -> bool,
Reorders the elements of this iterator in-place according to the given predicate,
such that all those that return true
precede all those that return false
.
Returns the number of true
elements found. Read more
sourcefn is_partitioned<P>(self, predicate: P) -> bool where
P: FnMut(Self::Item) -> bool,
fn is_partitioned<P>(self, predicate: P) -> bool where
P: FnMut(Self::Item) -> bool,
Checks if the elements of this iterator are partitioned according to the given predicate,
such that all those that return true
precede all those that return false
. Read more
1.27.0 · sourcefn try_fold<B, F, R>(&mut self, init: B, f: F) -> R where
F: FnMut(B, Self::Item) -> R,
R: Try<Output = B>,
fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R where
F: FnMut(B, Self::Item) -> R,
R: Try<Output = B>,
An iterator method that applies a function as long as it returns successfully, producing a single, final value. Read more
1.27.0 · sourcefn try_for_each<F, R>(&mut self, f: F) -> R where
F: FnMut(Self::Item) -> R,
R: Try<Output = ()>,
fn try_for_each<F, R>(&mut self, f: F) -> R where
F: FnMut(Self::Item) -> R,
R: Try<Output = ()>,
An iterator method that applies a fallible function to each item in the iterator, stopping at the first error and returning that error. Read more
sourcefn fold<B, F>(self, init: B, f: F) -> B where
F: FnMut(B, Self::Item) -> B,
fn fold<B, F>(self, init: B, f: F) -> B where
F: FnMut(B, Self::Item) -> B,
Folds every element into an accumulator by applying an operation, returning the final result. Read more
1.51.0 · sourcefn reduce<F>(self, f: F) -> Option<Self::Item> where
F: FnMut(Self::Item, Self::Item) -> Self::Item,
fn reduce<F>(self, f: F) -> Option<Self::Item> where
F: FnMut(Self::Item, Self::Item) -> Self::Item,
Reduces the elements to a single one, by repeatedly applying a reducing operation. Read more
sourcefn try_reduce<F, R>(
&mut self,
f: F
) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType where
F: FnMut(Self::Item, Self::Item) -> R,
R: Try<Output = Self::Item>,
<R as Try>::Residual: Residual<Option<Self::Item>>,
fn try_reduce<F, R>(
&mut self,
f: F
) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType where
F: FnMut(Self::Item, Self::Item) -> R,
R: Try<Output = Self::Item>,
<R as Try>::Residual: Residual<Option<Self::Item>>,
Reduces the elements to a single one by repeatedly applying a reducing operation. If the closure returns a failure, the failure is propagated back to the caller immediately. Read more
sourcefn all<F>(&mut self, f: F) -> bool where
F: FnMut(Self::Item) -> bool,
fn all<F>(&mut self, f: F) -> bool where
F: FnMut(Self::Item) -> bool,
Tests if every element of the iterator matches a predicate. Read more
sourcefn any<F>(&mut self, f: F) -> bool where
F: FnMut(Self::Item) -> bool,
fn any<F>(&mut self, f: F) -> bool where
F: FnMut(Self::Item) -> bool,
Tests if any element of the iterator matches a predicate. Read more
sourcefn find<P>(&mut self, predicate: P) -> Option<Self::Item> where
P: FnMut(&Self::Item) -> bool,
fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where
P: FnMut(&Self::Item) -> bool,
Searches for an element of an iterator that satisfies a predicate. Read more
1.30.0 · sourcefn find_map<B, F>(&mut self, f: F) -> Option<B> where
F: FnMut(Self::Item) -> Option<B>,
fn find_map<B, F>(&mut self, f: F) -> Option<B> where
F: FnMut(Self::Item) -> Option<B>,
Applies function to the elements of iterator and returns the first non-none result. Read more
sourcefn try_find<F, R>(
&mut self,
f: F
) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType where
F: FnMut(&Self::Item) -> R,
R: Try<Output = bool>,
<R as Try>::Residual: Residual<Option<Self::Item>>,
fn try_find<F, R>(
&mut self,
f: F
) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType where
F: FnMut(&Self::Item) -> R,
R: Try<Output = bool>,
<R as Try>::Residual: Residual<Option<Self::Item>>,
Applies function to the elements of iterator and returns the first true result or the first error. Read more
sourcefn position<P>(&mut self, predicate: P) -> Option<usize> where
P: FnMut(Self::Item) -> bool,
fn position<P>(&mut self, predicate: P) -> Option<usize> where
P: FnMut(Self::Item) -> bool,
Searches for an element in an iterator, returning its index. Read more
sourcefn rposition<P>(&mut self, predicate: P) -> Option<usize> where
P: FnMut(Self::Item) -> bool,
Self: ExactSizeIterator + DoubleEndedIterator,
fn rposition<P>(&mut self, predicate: P) -> Option<usize> where
P: FnMut(Self::Item) -> bool,
Self: ExactSizeIterator + DoubleEndedIterator,
Searches for an element in an iterator from the right, returning its index. Read more
sourcefn max(self) -> Option<Self::Item> where
Self::Item: Ord,
fn max(self) -> Option<Self::Item> where
Self::Item: Ord,
Returns the maximum element of an iterator. Read more
sourcefn min(self) -> Option<Self::Item> where
Self::Item: Ord,
fn min(self) -> Option<Self::Item> where
Self::Item: Ord,
Returns the minimum element of an iterator. Read more
1.6.0 · sourcefn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where
B: Ord,
F: FnMut(&Self::Item) -> B,
fn max_by_key<B, F>(self, f: F) -> Option<Self::Item> where
B: Ord,
F: FnMut(&Self::Item) -> B,
Returns the element that gives the maximum value from the specified function. Read more
1.15.0 · sourcefn max_by<F>(self, compare: F) -> Option<Self::Item> where
F: FnMut(&Self::Item, &Self::Item) -> Ordering,
fn max_by<F>(self, compare: F) -> Option<Self::Item> where
F: FnMut(&Self::Item, &Self::Item) -> Ordering,
Returns the element that gives the maximum value with respect to the specified comparison function. Read more
1.6.0 · sourcefn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where
B: Ord,
F: FnMut(&Self::Item) -> B,
fn min_by_key<B, F>(self, f: F) -> Option<Self::Item> where
B: Ord,
F: FnMut(&Self::Item) -> B,
Returns the element that gives the minimum value from the specified function. Read more
1.15.0 · sourcefn min_by<F>(self, compare: F) -> Option<Self::Item> where
F: FnMut(&Self::Item, &Self::Item) -> Ordering,
fn min_by<F>(self, compare: F) -> Option<Self::Item> where
F: FnMut(&Self::Item, &Self::Item) -> Ordering,
Returns the element that gives the minimum value with respect to the specified comparison function. Read more
sourcefn rev(self) -> Rev<Self> where
Self: DoubleEndedIterator,
fn rev(self) -> Rev<Self> where
Self: DoubleEndedIterator,
Reverses an iterator’s direction. Read more
sourcefn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where
FromA: Default + Extend<A>,
FromB: Default + Extend<B>,
Self: Iterator<Item = (A, B)>,
fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where
FromA: Default + Extend<A>,
FromB: Default + Extend<B>,
Self: Iterator<Item = (A, B)>,
Converts an iterator of pairs into a pair of containers. Read more
1.36.0 · sourcefn copied<'a, T>(self) -> Copied<Self> where
T: 'a + Copy,
Self: Iterator<Item = &'a T>,
fn copied<'a, T>(self) -> Copied<Self> where
T: 'a + Copy,
Self: Iterator<Item = &'a T>,
Creates an iterator which copies all of its elements. Read more
1.11.0 · sourcefn sum<S>(self) -> S where
S: Sum<Self::Item>,
fn sum<S>(self) -> S where
S: Sum<Self::Item>,
Sums the elements of an iterator. Read more
1.11.0 · sourcefn product<P>(self) -> P where
P: Product<Self::Item>,
fn product<P>(self) -> P where
P: Product<Self::Item>,
Iterates over the entire iterator, multiplying all the elements Read more
1.5.0 · sourcefn cmp<I>(self, other: I) -> Ordering where
I: IntoIterator<Item = Self::Item>,
Self::Item: Ord,
fn cmp<I>(self, other: I) -> Ordering where
I: IntoIterator<Item = Self::Item>,
Self::Item: Ord,
Lexicographically compares the elements of this Iterator
with those
of another. Read more
sourcefn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering where
I: IntoIterator,
F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Ordering,
fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering where
I: IntoIterator,
F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Ordering,
Lexicographically compares the elements of this Iterator
with those
of another with respect to the specified comparison function. Read more
1.5.0 · sourcefn partial_cmp<I>(self, other: I) -> Option<Ordering> where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
fn partial_cmp<I>(self, other: I) -> Option<Ordering> where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
Lexicographically compares the elements of this Iterator
with those
of another. Read more
sourcefn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering> where
I: IntoIterator,
F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Option<Ordering>,
fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering> where
I: IntoIterator,
F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Option<Ordering>,
Lexicographically compares the elements of this Iterator
with those
of another with respect to the specified comparison function. Read more
1.5.0 · sourcefn eq<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialEq<<I as IntoIterator>::Item>,
fn eq<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialEq<<I as IntoIterator>::Item>,
sourcefn eq_by<I, F>(self, other: I, eq: F) -> bool where
I: IntoIterator,
F: FnMut(Self::Item, <I as IntoIterator>::Item) -> bool,
fn eq_by<I, F>(self, other: I, eq: F) -> bool where
I: IntoIterator,
F: FnMut(Self::Item, <I as IntoIterator>::Item) -> bool,
1.5.0 · sourcefn ne<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialEq<<I as IntoIterator>::Item>,
fn ne<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialEq<<I as IntoIterator>::Item>,
1.5.0 · sourcefn lt<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
fn lt<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
Determines if the elements of this Iterator
are lexicographically
less than those of another. Read more
1.5.0 · sourcefn le<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
fn le<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
Determines if the elements of this Iterator
are lexicographically
less or equal to those of another. Read more
1.5.0 · sourcefn gt<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
fn gt<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
Determines if the elements of this Iterator
are lexicographically
greater than those of another. Read more
1.5.0 · sourcefn ge<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
fn ge<I>(self, other: I) -> bool where
I: IntoIterator,
Self::Item: PartialOrd<<I as IntoIterator>::Item>,
Determines if the elements of this Iterator
are lexicographically
greater than or equal to those of another. Read more
sourcefn is_sorted(self) -> bool where
Self::Item: PartialOrd<Self::Item>,
fn is_sorted(self) -> bool where
Self::Item: PartialOrd<Self::Item>,
Checks if the elements of this iterator are sorted. Read more
sourcefn is_sorted_by<F>(self, compare: F) -> bool where
F: FnMut(&Self::Item, &Self::Item) -> Option<Ordering>,
fn is_sorted_by<F>(self, compare: F) -> bool where
F: FnMut(&Self::Item, &Self::Item) -> Option<Ordering>,
Checks if the elements of this iterator are sorted using the given comparator function. Read more
sourcefn is_sorted_by_key<F, K>(self, f: F) -> bool where
F: FnMut(Self::Item) -> K,
K: PartialOrd<K>,
fn is_sorted_by_key<F, K>(self, f: F) -> bool where
F: FnMut(Self::Item) -> K,
K: PartialOrd<K>,
Checks if the elements of this iterator are sorted using the given key extraction function. Read more
impl<K, V, A: Allocator> FusedIterator for IntoIter<K, V, A>
Auto Trait Implementations
impl<K, V, A> RefUnwindSafe for IntoIter<K, V, A> where
A: RefUnwindSafe,
K: RefUnwindSafe,
V: RefUnwindSafe,
impl<K, V, A> Send for IntoIter<K, V, A> where
A: Send,
K: Send,
V: Send,
impl<K, V, A> Sync for IntoIter<K, V, A> where
A: Sync,
K: Sync,
V: Sync,
impl<K, V, A> Unpin for IntoIter<K, V, A> where
A: Unpin,
impl<K, V, A> UnwindSafe for IntoIter<K, V, A> where
A: UnwindSafe,
K: RefUnwindSafe,
V: RefUnwindSafe,
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more