GeezerVison is showing doc.rust-lang.org — IntoIter in std::array - Rust Struct IntoIter 1.51.0 · Source pub struct IntoIter<T, const N: usize> { /* private fields */ }
Expand descriptionA by-value array iterator.
Implementations§
👎Deprecated since 1.59.0: use IntoIterator::into_iter instead
Creates a new iterator over the given array.
🔬This is a nightly-only experimental API. (array_into_iter_constructors #91583)
Creates an iterator over the elements in a partially-initialized buffer.
If you have a fully-initialized array, then use IntoIterator.
But this is useful for returning partial results from unsafe code.
§Safety
- The
buffer[initialized] elements must all be initialized.
- The range must be canonical, with
initialized.start <= initialized.end.
- The range must be in-bounds for the buffer, with
initialized.end <= N.
(Like how indexing [0][100..100] fails despite the range being empty.)
It’s sound to have more elements initialized than mentioned, though that
will most likely result in them being leaked.
§Examples
#![feature(array_into_iter_constructors)]
#![feature(maybe_uninit_uninit_array_transpose)]
use std::array::IntoIter;
use std::mem::MaybeUninit;
fn next_chunk<T: Copy, const N: usize>(
it: &mut impl Iterator<Item = T>,
) -> Result<[T; N], IntoIter<T, N>> {
let mut buffer = [const { MaybeUninit::uninit() }; N];
let mut i = 0;
while i < N {
match it.next() {
Some(x) => {
buffer[i].write(x);
i += 1;
}
None => {
// SAFETY: We've initialized the first `i` items
unsafe {
return Err(IntoIter::new_unchecked(buffer, 0..i));
}
}
}
}
// SAFETY: We've initialized all N items
unsafe { Ok(buffer.transpose().assume_init()) }
}
let r: [_; 4] = next_chunk(&mut (10..16)).unwrap();
assert_eq!(r, [10, 11, 12, 13]);
let r: IntoIter<_, 40> = next_chunk(&mut (10..16)).unwrap_err();
assert_eq!(r.collect::<Vec<_>>(), vec![10, 11, 12, 13, 14, 15]);
🔬This is a nightly-only experimental API. (array_into_iter_constructors #91583)
Creates an iterator over T which returns no elements.
If you just need an empty iterator, then use
iter::empty() instead.
And if you need an empty array, use [].
But this is useful when you need an array::IntoIter<T, N> specifically.
§Examples
#![feature(array_into_iter_constructors)]
use std::array::IntoIter;
let empty = IntoIter::<i32, 3>::empty();
assert_eq!(empty.len(), 0);
assert_eq!(empty.as_slice(), &[]);
let empty = IntoIter::<std::convert::Infallible, 200>::empty();
assert_eq!(empty.len(), 0);
[1, 2].into_iter() and [].into_iter() have different types
#![feature(array_into_iter_constructors)]
use std::array::IntoIter;
pub fn get_bytes(b: bool) -> IntoIter<i8, 4> {
if b {
[1, 2, 3, 4].into_iter()
} else {
[].into_iter() // error[E0308]: mismatched types
}
}
But using this method you can get an empty iterator of appropriate size:
ⓘ#![feature(array_into_iter_constructors)]
use std::array::IntoIter;
pub fn get_bytes(b: bool) -> IntoIter<i8, 4> {
if b {
[1, 2, 3, 4].into_iter()
} else {
IntoIter::empty()
}
}
assert_eq!(get_bytes(true).collect::<Vec<_>>(), vec![1, 2, 3, 4]);
assert_eq!(get_bytes(false).collect::<Vec<_>>(), vec![]);
Returns an immutable slice of all elements that have not been yielded
yet.
Returns a mutable slice of all elements that have not been yielded yet.
Trait Implementations§
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
Removes and returns an element from the end of the iterator. Read moreSource§fn rfold<Acc, Fold>(self, init: Acc, rfold: Fold) -> AccAn iterator method that reduces the iterator’s elements to a single,
final value, starting from the back. Read more
🔬This is a nightly-only experimental API. (iter_advance_by #77404) Advances the iterator from the back by n elements. Read more
🔬This is a nightly-only experimental API. (iter_next_chunk #98326) Advances from the back of the iterator and returns an array containing the next
N values in sequence. Read more
Returns the nth element from the end of the iterator. Read more
Searches for an element of an iterator from the back that satisfies a predicate. Read more
Executes the destructor for this type. Read more
🔬This is a nightly-only experimental API. (pin_ergonomics #130494) Execute the destructor for this type, but different to Drop::drop, it requires self
to be pinned. Read more
Returns the exact remaining length of the iterator. Read more
🔬This is a nightly-only experimental API. (exact_size_is_empty #35428) Returns true if the iterator is empty. Read more
The type of the elements being iterated over.
Advances the iterator and returns the next value. Read more
Returns the bounds on the remaining length of the iterator. Read moreSource§fn fold<Acc, Fold>(self, init: Acc, fold: Fold) -> AccFolds every element into an accumulator by applying an operation,
returning the final result. Read more
An iterator method that applies a function as long as it returns
successfully, producing a single, final value. Read more
Consumes the iterator, counting the number of iterations and returning it. Read more
Consumes the iterator, returning the last element. Read more
🔬This is a nightly-only experimental API. (iter_advance_by #77404) Advances the iterator by n elements. Read more
🔬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
Returns the nth element of the iterator. Read more
Creates an iterator starting at the same point, but stepping by
the given amount at each iteration. Read more
Takes two iterators and creates a new iterator over both in sequence. Read more
‘Zips up’ two iterators into a single iterator of pairs. Read more
🔬This is a nightly-only experimental API. (iter_intersperse #79524) Creates a new iterator which places a copy of separator between items
of the original iterator. Read more
🔬This is a nightly-only experimental API. (iter_intersperse #79524) Creates a new iterator which places an item generated by separator
between items of the original iterator. Read more
Takes a closure and creates an iterator which calls that closure on each
element. Read more
Calls a closure on each element of an iterator. Read more
Creates an iterator which uses a closure to determine if an element
should be yielded. Read more
Creates an iterator that both filters and maps. Read more
Creates an iterator which gives the current iteration count as well as
the next value. Read more
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
Creates an iterator that skips elements based on a predicate. Read more
Creates an iterator that yields elements based on a predicate. Read more
Creates an iterator that both yields elements based on a predicate and maps. Read more
Creates an iterator that skips the first n elements. Read more
Creates an iterator that yields the first n elements, or fewer
if the underlying iterator ends sooner. Read more
An iterator adapter which, like fold, holds internal state, but
unlike fold, produces a new iterator. Read more
Creates an iterator that works like map, but flattens nested structure. Read more
Creates an iterator that flattens nested structure. Read more
🔬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
Does something with each element of an iterator, passing the value on. Read more
Creates a “by reference” adapter for this instance of Iterator. Read more
Transforms an iterator into a collection. Read more
🔬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
🔬This is a nightly-only experimental API. (iter_collect_into #94780) Collects all the items from an iterator into a collection. Read more
Consumes an iterator, creating two collections from it. Read more
🔬This is a nightly-only experimental API. (iter_partition_in_place #62543) 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
🔬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
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
Reduces the elements to a single one, by repeatedly applying a reducing
operation. Read more
🔬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
Tests if every element of the iterator matches a predicate. Read more
Tests if any element of the iterator matches a predicate. Read more
Searches for an element of an iterator that satisfies a predicate. Read more
Applies function to the elements of iterator and returns
the first non-none result. Read more
🔬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
Searches for an element in an iterator, returning its index. Read more
Searches for an element in an iterator from the right, returning its
index. Read more
Returns the maximum element of an iterator. Read more
Returns the minimum element of an iterator. Read more
Returns the element that gives the maximum value from the
specified function. Read more
Returns the element that gives the maximum value with respect to the
specified comparison function. Read more
Returns the element that gives the minimum value from the
specified function. Read more
Returns the element that gives the minimum value with respect to the
specified comparison function. Read more
Converts an iterator of pairs into a pair of containers. Read more
Creates an iterator which copies all of its elements. Read more
🔬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
Iterates over the entire iterator, multiplying all the elements. Read more
🔬This is a nightly-only experimental API. (iter_order_by #64295)
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
🔬This is a nightly-only experimental API. (iter_order_by #64295)
🔬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
Determines if the elements of this Iterator are not equal to those of
another. Read more
Checks if the elements of this iterator are sorted. Read more
Checks if the elements of this iterator are sorted using the given comparator function. Read more
Checks if the elements of this iterator are sorted using the given key extraction
function. Read moreAuto Trait Implementations§Blanket Implementations§
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more
🔬This is a nightly-only experimental API. (clone_to_uninit #126799) Performs copy-assignment from self to dest. Read more
Returns the argument unchanged.
Calls U::from(self).
That is, this conversion is whatever the implementation of
From<T> for U chooses to do.
The type of the elements being iterated over.
Which kind of iterator are we turning this into?
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
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. |