## ExtractIf

# Struct ExtractIf

1.91.0 · Source

    pub struct ExtractIf<'a, T, R, F, A: Allocator + Clone = Global> { /* private fields */ }

Expand description

An iterator produced by calling `extract_if` on BTreeSet.

## Trait Implementations§

1.91.0 · Source§

### impl<T, R, F, A> Debug for ExtractIf<'_, T, R, F, A>
where T: Debug, A: Allocator + Clone,

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

Formats the value using the given formatter. Read more
1.91.0 · Source§

### impl<T, R, F, A: Allocator + Clone> Iterator for ExtractIf<'_, T, R, F, A>
where T: PartialOrd, R: RangeBounds<T>, F: FnMut(&T) -> bool,

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#### type Item = T

The type of the elements being iterated over.
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#### fn next(&mut self) -> Option<T>

Advances the iterator and returns the next value. Read more
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#### fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the iterator. Read more
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#### fn next_chunk<const N: usize>( &mut self, ) -> Result<[Self::Item; N], IntoIter<Self::Item, N>>
where Self: Sized,

🔬This is a nightly-only experimental API. (`iter_next_chunk` #98326)
Advances the iterator and returns an array containing the next `N` values. Read more
1.0.0 · Source§

#### fn count(self) -> usize
where Self: Sized,

Consumes the iterator, counting the number of iterations and returning it. Read more
1.0.0 · Source§

#### fn last(self) -> Option<Self::Item>
where Self: Sized,

Consumes the iterator, returning the last element. Read more
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#### fn advance_by(&mut self, n: usize) -> Result<(), NonZero<usize>>

🔬This is a nightly-only experimental API. (`iter_advance_by` #77404)
Advances the iterator by `n` elements. Read more
1.0.0 · Source§

#### fn nth(&mut self, n: usize) -> Option<Self::Item>

Returns the `n`th element of the iterator. Read more
1.28.0 · Source§

#### fn step_by(self, step: usize) -> StepBy<Self>
where Self: Sized,

Creates an iterator starting at the same point, but stepping by the given amount at each iteration. Read more
1.0.0 · Source§

#### fn chain<U>(self, other: U) -> Chain<Self, <U as IntoIterator>::IntoIter>
where Self: Sized, U: IntoIterator<Item = Self::Item>,

Takes two iterators and creates a new iterator over both in sequence. Read more
1.0.0 · Source§

#### fn zip<U>(self, other: U) -> Zip<Self, <U as IntoIterator>::IntoIter>
where Self: Sized, U: IntoIterator,

‘Zips up’ two iterators into a single iterator of pairs. Read more
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#### fn intersperse(self, separator: Self::Item) -> Intersperse<Self>
where Self: Sized, Self::Item: Clone,

🔬This is a nightly-only experimental API. (`iter_intersperse` #79524)
Creates a new iterator which places a copy of `separator` between adjacent items of the original iterator. Read more
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#### fn intersperse_with<G>(self, separator: G) -> IntersperseWith<Self, G>
where Self: Sized, G: FnMut() -> Self::Item,

🔬This is a nightly-only experimental API. (`iter_intersperse` #79524)
Creates a new iterator which places an item generated by `separator` between adjacent items of the original iterator. Read more
1.0.0 · Source§

#### fn map<B, F>(self, f: F) -> Map<Self, F>
where Self: Sized, F: FnMut(Self::Item) -> B,

Takes a closure and creates an iterator which calls that closure on each element. Read more
1.21.0 · Source§

#### fn for_each<F>(self, f: F)
where Self: Sized, F: FnMut(Self::Item),

Calls a closure on each element of an iterator. Read more
1.0.0 · Source§

#### fn filter<P>(self, predicate: P) -> Filter<Self, P>
where Self: Sized, P: FnMut(&Self::Item) -> bool,

Creates an iterator which uses a closure to determine if an element should be yielded. Read more
1.0.0 · Source§

#### fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F>
where Self: Sized, F: FnMut(Self::Item) -> Option<B>,

Creates an iterator that both filters and maps. Read more
1.0.0 · Source§

#### fn enumerate(self) -> Enumerate<Self>
where Self: Sized,

Creates an iterator which gives the current iteration count as well as the next value. Read more
1.0.0 · Source§

#### fn peekable(self) -> Peekable<Self>
where Self: Sized,

Creates an iterator which can use the `peek` and `peek_mut` methods to look at the next element of the iterator without consuming it. See their documentation for more information. Read more
1.0.0 · Source§

#### fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P>
where Self: Sized, P: FnMut(&Self::Item) -> bool,

Creates an iterator that `skip`s elements based on a predicate. Read more
1.0.0 · Source§

#### fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P>
where Self: Sized, P: FnMut(&Self::Item) -> bool,

Creates an iterator that yields elements based on a predicate. Read more
1.57.0 · Source§

#### fn map_while<B, P>(self, predicate: P) -> MapWhile<Self, P>
where Self: Sized, P: FnMut(Self::Item) -> Option<B>,

Creates an iterator that both yields elements based on a predicate and maps. Read more
1.0.0 · Source§

#### fn skip(self, n: usize) -> Skip<Self>
where Self: Sized,

Creates an iterator that skips the first `n` elements. Read more
1.0.0 · Source§

#### fn take(self, n: usize) -> Take<Self>
where Self: Sized,

Creates an iterator that yields the first `n` elements, or fewer if the underlying iterator ends sooner. Read more
1.0.0 · Source§

#### fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F>
where Self: Sized, F: FnMut(&mut St, Self::Item) -> Option<B>,

An iterator adapter which, like `fold`, holds internal state, but unlike `fold`, produces a new iterator. Read more
1.0.0 · Source§

#### fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>
where Self: Sized, U: IntoIterator, F: FnMut(Self::Item) -> U,

Creates an iterator that works like map, but flattens nested structure. Read more
1.29.0 · Source§

#### fn flatten(self) -> Flatten<Self>
where Self: Sized, Self::Item: IntoIterator,

Creates an iterator that flattens nested structure. Read more
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#### fn map_windows<F, R, const N: usize>(self, f: F) -> MapWindows<Self, F, N>
where Self: Sized, F: FnMut(&[Self::Item; N]) -> R,

🔬This is a nightly-only experimental API. (`iter_map_windows` #87155)
Calls the given function `f` for each contiguous window of size `N` over `self` and returns an iterator over the outputs of `f`. Like `slice::windows()`, the windows during mapping overlap as well. Read more
1.0.0 · Source§

#### fn fuse(self) -> Fuse<Self>
where Self: Sized,

Creates an iterator which ends after the first `None`. Read more
1.0.0 · Source§

#### fn inspect<F>(self, f: F) -> Inspect<Self, F>
where Self: Sized, F: FnMut(&Self::Item),

Does something with each element of an iterator, passing the value on. Read more
1.0.0 · Source§

#### fn by_ref(&mut self) -> &mut Self
where Self: Sized,

Creates a “by reference” adapter for this instance of `Iterator`. Read more
1.0.0 · Source§

#### fn collect<B>(self) -> B
where B: FromIterator<Self::Item>, Self: Sized,

Transforms an iterator into a collection. Read more
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#### fn try_collect<B>( &mut self, ) -> <<Self::Item as Try>::Residual as Residual<B>>::TryType
where Self: Sized, Self::Item: Try, <Self::Item as Try>::Residual: Residual<B>, B: FromIterator<<Self::Item as Try>::Output>,

🔬This is a nightly-only experimental API. (`iterator_try_collect` #94047)
Fallibly transforms an iterator into a collection, short circuiting if a failure is encountered. Read more
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#### fn collect_into<E>(self, collection: &mut E) -> &mut E
where E: Extend<Self::Item>, Self: Sized,

🔬This is a nightly-only experimental API. (`iter_collect_into` #94780)
Collects all the items from an iterator into a collection. Read more
1.0.0 · Source§

#### fn partition<B, F>(self, f: F) -> (B, B)
where Self: Sized, B: Default + Extend<Self::Item>, F: FnMut(&Self::Item) -> bool,

Consumes an iterator, creating two collections from it. Read more
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#### fn is_partitioned<P>(self, predicate: P) -> bool
where Self: Sized, P: FnMut(Self::Item) -> bool,

🔬This is a nightly-only experimental API. (`iter_is_partitioned` #62544)
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 · Source§

#### fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R
where Self: Sized, 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 · Source§

#### fn try_for_each<F, R>(&mut self, f: F) -> R
where Self: Sized, 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
1.0.0 · Source§

#### fn fold<B, F>(self, init: B, f: F) -> B
where Self: Sized, 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 · Source§

#### fn reduce<F>(self, f: F) -> Option<Self::Item>
where Self: Sized, F: FnMut(Self::Item, Self::Item) -> Self::Item,

Reduces the elements to a single one, by repeatedly applying a reducing operation. Read more
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#### fn try_reduce<R>( &mut self, f: impl FnMut(Self::Item, Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<<R as Try>::Output>>>::TryType
where Self: Sized, R: Try<Output = Self::Item>, <R as Try>::Residual: Residual<Option<Self::Item>>,

🔬This is a nightly-only experimental API. (`iterator_try_reduce` #87053)
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
1.0.0 · Source§

#### fn all<F>(&mut self, f: F) -> bool
where Self: Sized, F: FnMut(Self::Item) -> bool,

Tests if every element of the iterator matches a predicate. Read more
1.0.0 · Source§

#### fn any<F>(&mut self, f: F) -> bool
where Self: Sized, F: FnMut(Self::Item) -> bool,

Tests if any element of the iterator matches a predicate. Read more
1.0.0 · Source§

#### fn find<P>(&mut self, predicate: P) -> Option<Self::Item>
where Self: Sized, P: FnMut(&Self::Item) -> bool,

Searches for an element of an iterator that satisfies a predicate. Read more
1.30.0 · Source§

#### fn find_map<B, F>(&mut self, f: F) -> Option<B>
where Self: Sized, F: FnMut(Self::Item) -> Option<B>,

Applies function to the elements of iterator and returns the first non-none result. Read more
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#### fn try_find<R>( &mut self, f: impl FnMut(&Self::Item) -> R, ) -> <<R as Try>::Residual as Residual<Option<Self::Item>>>::TryType
where Self: Sized, R: Try<Output = bool>, <R as Try>::Residual: Residual<Option<Self::Item>>,

🔬This is a nightly-only experimental API. (`try_find` #63178)
Applies function to the elements of iterator and returns the first true result or the first error. Read more
1.0.0 · Source§

#### fn position<P>(&mut self, predicate: P) -> Option<usize>
where Self: Sized, P: FnMut(Self::Item) -> bool,

Searches for an element in an iterator, returning its index. Read more
1.0.0 · Source§

#### fn max(self) -> Option<Self::Item>
where Self: Sized, Self::Item: Ord,

Returns the maximum element of an iterator. Read more
1.0.0 · Source§

#### fn min(self) -> Option<Self::Item>
where Self: Sized, Self::Item: Ord,

Returns the minimum element of an iterator. Read more
1.6.0 · Source§

#### fn max_by_key<B, F>(self, f: F) -> Option<Self::Item>
where B: Ord, Self: Sized, F: FnMut(&Self::Item) -> B,

Returns the element that gives the maximum value from the specified function. Read more
1.15.0 · Source§

#### fn max_by<F>(self, compare: F) -> Option<Self::Item>
where Self: Sized, 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 · Source§

#### fn min_by_key<B, F>(self, f: F) -> Option<Self::Item>
where B: Ord, Self: Sized, F: FnMut(&Self::Item) -> B,

Returns the element that gives the minimum value from the specified function. Read more
1.15.0 · Source§

#### fn min_by<F>(self, compare: F) -> Option<Self::Item>
where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> Ordering,

Returns the element that gives the minimum value with respect to the specified comparison function. Read more
1.0.0 · Source§

#### fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)
where FromA: Default + Extend<A>, FromB: Default + Extend<B>, Self: Sized + Iterator<Item = (A, B)>,

Converts an iterator of pairs into a pair of containers. Read more
1.36.0 · Source§

#### fn copied<'a, T>(self) -> Copied<Self>
where T: Copy + 'a, Self: Sized + Iterator<Item = &'a T>,

Creates an iterator which copies all of its elements. Read more
1.0.0 · Source§

#### fn cloned<'a, T>(self) -> Cloned<Self>
where T: Clone + 'a, Self: Sized + Iterator<Item = &'a T>,

Creates an iterator which `clone`s all of its elements. Read more
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#### fn array_chunks<const N: usize>(self) -> ArrayChunks<Self, N>
where Self: Sized,

🔬This is a nightly-only experimental API. (`iter_array_chunks` #100450)
Returns an iterator over `N` elements of the iterator at a time. Read more
1.11.0 · Source§

#### fn sum<S>(self) -> S
where Self: Sized, S: Sum<Self::Item>,

Sums the elements of an iterator. Read more
1.11.0 · Source§

#### fn product<P>(self) -> P
where Self: Sized, P: Product<Self::Item>,

Iterates over the entire iterator, multiplying all the elements Read more
1.5.0 · Source§

#### fn cmp<I>(self, other: I) -> Ordering
where I: IntoIterator<Item = Self::Item>, Self::Item: Ord, Self: Sized,

Lexicographically compares the elements of this `Iterator` with those of another. Read more
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#### fn cmp_by<I, F>(self, other: I, cmp: F) -> Ordering
where Self: Sized, I: IntoIterator, F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Ordering,

🔬This is a nightly-only experimental API. (`iter_order_by` #64295)
Lexicographically compares the elements of this `Iterator` with those of another with respect to the specified comparison function. Read more
1.5.0 · Source§

#### fn partial_cmp<I>(self, other: I) -> Option<Ordering>
where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,

Lexicographically compares the `PartialOrd` elements of this `Iterator` with those of another. The comparison works like short-circuit evaluation, returning a result without comparing the remaining elements. As soon as an order can be determined, the evaluation stops and a result is returned. Read more
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#### fn partial_cmp_by<I, F>(self, other: I, partial_cmp: F) -> Option<Ordering>
where Self: Sized, I: IntoIterator, F: FnMut(Self::Item, <I as IntoIterator>::Item) -> Option<Ordering>,

🔬This is a nightly-only experimental API. (`iter_order_by` #64295)
Lexicographically compares the elements of this `Iterator` with those of another with respect to the specified comparison function. Read more
1.5.0 · Source§

#### fn eq<I>(self, other: I) -> bool
where I: IntoIterator, Self::Item: PartialEq<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this `Iterator` are equal to those of another. Read more
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#### fn eq_by<I, F>(self, other: I, eq: F) -> bool
where Self: Sized, I: IntoIterator, F: FnMut(Self::Item, <I as IntoIterator>::Item) -> bool,

🔬This is a nightly-only experimental API. (`iter_order_by` #64295)
Determines if the elements of this `Iterator` are equal to those of another with respect to the specified equality function. Read more
1.5.0 · Source§

#### fn ne<I>(self, other: I) -> bool
where I: IntoIterator, Self::Item: PartialEq<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this `Iterator` are not equal to those of another. Read more
1.5.0 · Source§

#### fn lt<I>(self, other: I) -> bool
where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this `Iterator` are lexicographically less than those of another. Read more
1.5.0 · Source§

#### fn le<I>(self, other: I) -> bool
where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this `Iterator` are lexicographically less or equal to those of another. Read more
1.5.0 · Source§

#### fn gt<I>(self, other: I) -> bool
where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this `Iterator` are lexicographically greater than those of another. Read more
1.5.0 · Source§

#### fn ge<I>(self, other: I) -> bool
where I: IntoIterator, Self::Item: PartialOrd<<I as IntoIterator>::Item>, Self: Sized,

Determines if the elements of this `Iterator` are lexicographically greater than or equal to those of another. Read more
1.82.0 · Source§

#### fn is_sorted(self) -> bool
where Self: Sized, Self::Item: PartialOrd,

Checks if the elements of this iterator are sorted. Read more
1.82.0 · Source§

#### fn is_sorted_by<F>(self, compare: F) -> bool
where Self: Sized, F: FnMut(&Self::Item, &Self::Item) -> bool,

Checks if the elements of this iterator are sorted using the given comparator function. Read more
1.82.0 · Source§

#### fn is_sorted_by_key<F, K>(self, f: F) -> bool
where Self: Sized, F: FnMut(Self::Item) -> K, K: PartialOrd,

Checks if the elements of this iterator are sorted using the given key extraction function. Read more
1.91.0 · Source§

### impl<T, R, F, A: Allocator + Clone> FusedIterator for ExtractIf<'_, T, R, F, A>
where T: PartialOrd, R: RangeBounds<T>, F: FnMut(&T) -> bool,

## Auto Trait Implementations§

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### impl<'a, T, R, F, A> Freeze for ExtractIf<'a, T, R, F, A>
where F: Freeze, A: Freeze, R: Freeze,

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### impl<'a, T, R, F, A> RefUnwindSafe for ExtractIf<'a, T, R, F, A>
where F: RefUnwindSafe, A: RefUnwindSafe, R: RefUnwindSafe, T: RefUnwindSafe,

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### impl<'a, T, R, F, A> Send for ExtractIf<'a, T, R, F, A>
where F: Send, A: Send, R: Send, T: Send,

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### impl<'a, T, R, F, A> Sync for ExtractIf<'a, T, R, F, A>
where F: Sync, A: Sync, R: Sync, T: Sync,

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### impl<'a, T, R, F, A> Unpin for ExtractIf<'a, T, R, F, A>
where F: Unpin, A: Unpin, R: Unpin,

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### impl<'a, T, R, F, A = Global> !UnwindSafe for ExtractIf<'a, T, R, F, A>

## Blanket Implementations§

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### impl<T> Any for T
where 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 T
where 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 T
where 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> 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 T
where 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<I> IntoIterator for I
where I: Iterator,

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#### type Item = <I as Iterator>::Item

The type of the elements being iterated over.
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#### type IntoIter = I

Which kind of iterator are we turning this into?
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#### fn into_iter(self) -> I

Creates an iterator from a value. Read more
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### impl<T, U> TryFrom<U> for T
where 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 T
where 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.