Struct merkletree::store::VecStore

pub struct VecStore<E: Element>(/* private fields */);

Methods from Deref<Target = [E]>

pub fn len(&self) -> usize

Returns the number of elements in the slice.

Examples

let a = [1, 2, 3];
assert_eq!(a.len(), 3);

pub fn is_empty(&self) -> bool

Returns true if the slice has a length of 0.

Examples

let a = [1, 2, 3];
assert!(!a.is_empty());

let b: &[i32] = &[];
assert!(b.is_empty());

pub fn first(&self) -> Option<&T>

Returns the first element of the slice, or None if it is empty.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&10), v.first());

let w: &[i32] = &[];
assert_eq!(None, w.first());

pub fn split_first(&self) -> Option<(&T, &[T])>

Returns the first and all the rest of the elements of the slice, or None if it is empty.

Examples

let x = &[0, 1, 2];

if let Some((first, elements)) = x.split_first() {
    assert_eq!(first, &0);
    assert_eq!(elements, &[1, 2]);
}

pub fn split_last(&self) -> Option<(&T, &[T])>

Returns the last and all the rest of the elements of the slice, or None if it is empty.

Examples

let x = &[0, 1, 2];

if let Some((last, elements)) = x.split_last() {
    assert_eq!(last, &2);
    assert_eq!(elements, &[0, 1]);
}

pub fn last(&self) -> Option<&T>

Returns the last element of the slice, or None if it is empty.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&30), v.last());

let w: &[i32] = &[];
assert_eq!(None, w.last());

pub fn first_chunk<const N: usize>(&self) -> Option<&[T; N]>

Return an array reference to the first N items in the slice.

If the slice is not at least N in length, this will return None.

Examples

let u = [10, 40, 30];
assert_eq!(Some(&[10, 40]), u.first_chunk::<2>());

let v: &[i32] = &[10];
assert_eq!(None, v.first_chunk::<2>());

let w: &[i32] = &[];
assert_eq!(Some(&[]), w.first_chunk::<0>());

pub fn split_first_chunk<const N: usize>(&self) -> Option<(&[T; N], &[T])>

Return an array reference to the first N items in the slice and the remaining slice.

If the slice is not at least N in length, this will return None.

Examples

let x = &[0, 1, 2];

if let Some((first, elements)) = x.split_first_chunk::<2>() {
    assert_eq!(first, &[0, 1]);
    assert_eq!(elements, &[2]);
}

assert_eq!(None, x.split_first_chunk::<4>());

pub fn split_last_chunk<const N: usize>(&self) -> Option<(&[T], &[T; N])>

Return an array reference to the last N items in the slice and the remaining slice.

If the slice is not at least N in length, this will return None.

Examples

let x = &[0, 1, 2];

if let Some((elements, last)) = x.split_last_chunk::<2>() {
    assert_eq!(elements, &[0]);
    assert_eq!(last, &[1, 2]);
}

assert_eq!(None, x.split_last_chunk::<4>());

pub fn last_chunk<const N: usize>(&self) -> Option<&[T; N]>

Return an array reference to the last N items in the slice.

If the slice is not at least N in length, this will return None.

Examples

let u = [10, 40, 30];
assert_eq!(Some(&[40, 30]), u.last_chunk::<2>());

let v: &[i32] = &[10];
assert_eq!(None, v.last_chunk::<2>());

let w: &[i32] = &[];
assert_eq!(Some(&[]), w.last_chunk::<0>());

pub fn get<I>(&self, index: I) -> Option<&<I as SliceIndex<[T]>>::Output>

where I: SliceIndex<[T]>,

Returns a reference to an element or subslice depending on the type of index.

• If given a position, returns a reference to the element at that position or None if out of bounds.
• If given a range, returns the subslice corresponding to that range, or None if out of bounds.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&40), v.get(1));
assert_eq!(Some(&[10, 40][..]), v.get(0..2));
assert_eq!(None, v.get(3));
assert_eq!(None, v.get(0..4));

pub unsafe fn get_unchecked<I>( &self, index: I, ) -> &<I as SliceIndex<[T]>>::Output

where I: SliceIndex<[T]>,

Returns a reference to an element or subslice, without doing bounds checking.

For a safe alternative see get.

Safety

Calling this method with an out-of-bounds index is undefined behavior even if the resulting reference is not used.

You can think of this like .get(index).unwrap_unchecked(). It’s UB to call .get_unchecked(len), even if you immediately convert to a pointer. And it’s UB to call .get_unchecked(..len + 1), .get_unchecked(..=len), or similar.

Examples

let x = &[1, 2, 4];

unsafe {
    assert_eq!(x.get_unchecked(1), &2);
}

pub fn as_ptr(&self) -> *const T

Returns a raw pointer to the slice’s buffer.

The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.

The caller must also ensure that the memory the pointer (non-transitively) points to is never written to (except inside an UnsafeCell) using this pointer or any pointer derived from it. If you need to mutate the contents of the slice, use as_mut_ptr.

Modifying the container referenced by this slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.

Examples

let x = &[1, 2, 4];
let x_ptr = x.as_ptr();

unsafe {
    for i in 0..x.len() {
        assert_eq!(x.get_unchecked(i), &*x_ptr.add(i));
    }
}

pub fn as_ptr_range(&self) -> Range<*const T>

Returns the two raw pointers spanning the slice.

The returned range is half-open, which means that the end pointer points one past the last element of the slice. This way, an empty slice is represented by two equal pointers, and the difference between the two pointers represents the size of the slice.

See as_ptr for warnings on using these pointers. The end pointer requires extra caution, as it does not point to a valid element in the slice.

This function is useful for interacting with foreign interfaces which use two pointers to refer to a range of elements in memory, as is common in C++.

It can also be useful to check if a pointer to an element refers to an element of this slice:

let a = [1, 2, 3];
let x = &a[1] as *const _;
let y = &5 as *const _;

assert!(a.as_ptr_range().contains(&x));
assert!(!a.as_ptr_range().contains(&y));

pub fn iter(&self) -> Iter<'_, T>

Returns an iterator over the slice.

The iterator yields all items from start to end.

Examples

let x = &[1, 2, 4];
let mut iterator = x.iter();

assert_eq!(iterator.next(), Some(&1));
assert_eq!(iterator.next(), Some(&2));
assert_eq!(iterator.next(), Some(&4));
assert_eq!(iterator.next(), None);

pub fn windows(&self, size: usize) -> Windows<'_, T>

Returns an iterator over all contiguous windows of length size. The windows overlap. If the slice is shorter than size, the iterator returns no values.

Panics

Panics if size is 0.

Examples

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.windows(3);
assert_eq!(iter.next().unwrap(), &['l', 'o', 'r']);
assert_eq!(iter.next().unwrap(), &['o', 'r', 'e']);
assert_eq!(iter.next().unwrap(), &['r', 'e', 'm']);
assert!(iter.next().is_none());

If the slice is shorter than size:

let slice = ['f', 'o', 'o'];
let mut iter = slice.windows(4);
assert!(iter.next().is_none());

There’s no windows_mut, as that existing would let safe code violate the “only one &mut at a time to the same thing” rule. However, you can sometimes use Cell::as_slice_of_cells in conjunction with windows to accomplish something similar:

use std::cell::Cell;

let mut array = ['R', 'u', 's', 't', ' ', '2', '0', '1', '5'];
let slice = &mut array[..];
let slice_of_cells: &[Cell<char>] = Cell::from_mut(slice).as_slice_of_cells();
for w in slice_of_cells.windows(3) {
    Cell::swap(&w[0], &w[2]);
}
assert_eq!(array, ['s', 't', ' ', '2', '0', '1', '5', 'u', 'R']);

pub fn chunks(&self, chunk_size: usize) -> Chunks<'_, T>

Returns an iterator over chunk_size elements of the slice at a time, starting at the beginning of the slice.

The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last chunk will not have length chunk_size.

See chunks_exact for a variant of this iterator that returns chunks of always exactly chunk_size elements, and rchunks for the same iterator but starting at the end of the slice.

Panics

Panics if chunk_size is 0.

Examples

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.chunks(2);
assert_eq!(iter.next().unwrap(), &['l', 'o']);
assert_eq!(iter.next().unwrap(), &['r', 'e']);
assert_eq!(iter.next().unwrap(), &['m']);
assert!(iter.next().is_none());

pub fn chunks_exact(&self, chunk_size: usize) -> ChunksExact<'_, T>

Returns an iterator over chunk_size elements of the slice at a time, starting at the beginning of the slice.

The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last up to chunk_size-1 elements will be omitted and can be retrieved from the remainder function of the iterator.

Due to each chunk having exactly chunk_size elements, the compiler can often optimize the resulting code better than in the case of chunks.

See chunks for a variant of this iterator that also returns the remainder as a smaller chunk, and rchunks_exact for the same iterator but starting at the end of the slice.

Panics

Panics if chunk_size is 0.

Examples

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.chunks_exact(2);
assert_eq!(iter.next().unwrap(), &['l', 'o']);
assert_eq!(iter.next().unwrap(), &['r', 'e']);
assert!(iter.next().is_none());
assert_eq!(iter.remainder(), &['m']);

pub unsafe fn as_chunks_unchecked<const N: usize>(&self) -> &[[T; N]]

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

Splits the slice into a slice of N-element arrays, assuming that there’s no remainder.

Safety

This may only be called when

• The slice splits exactly into N-element chunks (aka self.len() % N == 0).
• N != 0.

Examples

#![feature(slice_as_chunks)]
let slice: &[char] = &['l', 'o', 'r', 'e', 'm', '!'];
let chunks: &[[char; 1]] =
    // SAFETY: 1-element chunks never have remainder
    unsafe { slice.as_chunks_unchecked() };
assert_eq!(chunks, &[['l'], ['o'], ['r'], ['e'], ['m'], ['!']]);
let chunks: &[[char; 3]] =
    // SAFETY: The slice length (6) is a multiple of 3
    unsafe { slice.as_chunks_unchecked() };
assert_eq!(chunks, &[['l', 'o', 'r'], ['e', 'm', '!']]);

// These would be unsound:
// let chunks: &[[_; 5]] = slice.as_chunks_unchecked() // The slice length is not a multiple of 5
// let chunks: &[[_; 0]] = slice.as_chunks_unchecked() // Zero-length chunks are never allowed

pub fn as_chunks<const N: usize>(&self) -> (&[[T; N]], &[T])

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

Splits the slice into a slice of N-element arrays, starting at the beginning of the slice, and a remainder slice with length strictly less than N.

Panics

Panics if N is 0. This check will most probably get changed to a compile time error before this method gets stabilized.

Examples

#![feature(slice_as_chunks)]
let slice = ['l', 'o', 'r', 'e', 'm'];
let (chunks, remainder) = slice.as_chunks();
assert_eq!(chunks, &[['l', 'o'], ['r', 'e']]);
assert_eq!(remainder, &['m']);

If you expect the slice to be an exact multiple, you can combine let-else with an empty slice pattern:

#![feature(slice_as_chunks)]
let slice = ['R', 'u', 's', 't'];
let (chunks, []) = slice.as_chunks::<2>() else {
    panic!("slice didn't have even length")
};
assert_eq!(chunks, &[['R', 'u'], ['s', 't']]);

pub fn as_rchunks<const N: usize>(&self) -> (&[T], &[[T; N]])

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

Splits the slice into a slice of N-element arrays, starting at the end of the slice, and a remainder slice with length strictly less than N.

Panics

Panics if N is 0. This check will most probably get changed to a compile time error before this method gets stabilized.

Examples

#![feature(slice_as_chunks)]
let slice = ['l', 'o', 'r', 'e', 'm'];
let (remainder, chunks) = slice.as_rchunks();
assert_eq!(remainder, &['l']);
assert_eq!(chunks, &[['o', 'r'], ['e', 'm']]);

pub fn array_chunks<const N: usize>(&self) -> ArrayChunks<'_, T, N>

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

Returns an iterator over N elements of the slice at a time, starting at the beginning of the slice.

The chunks are array references and do not overlap. If N does not divide the length of the slice, then the last up to N-1 elements will be omitted and can be retrieved from the remainder function of the iterator.

This method is the const generic equivalent of chunks_exact.

Panics

Panics if N is 0. This check will most probably get changed to a compile time error before this method gets stabilized.

Examples

#![feature(array_chunks)]
let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.array_chunks();
assert_eq!(iter.next().unwrap(), &['l', 'o']);
assert_eq!(iter.next().unwrap(), &['r', 'e']);
assert!(iter.next().is_none());
assert_eq!(iter.remainder(), &['m']);

pub fn array_windows<const N: usize>(&self) -> ArrayWindows<'_, T, N>

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

Returns an iterator over overlapping windows of N elements of a slice, starting at the beginning of the slice.

This is the const generic equivalent of windows.

If N is greater than the size of the slice, it will return no windows.

Panics

Panics if N is 0. This check will most probably get changed to a compile time error before this method gets stabilized.

Examples

#![feature(array_windows)]
let slice = [0, 1, 2, 3];
let mut iter = slice.array_windows();
assert_eq!(iter.next().unwrap(), &[0, 1]);
assert_eq!(iter.next().unwrap(), &[1, 2]);
assert_eq!(iter.next().unwrap(), &[2, 3]);
assert!(iter.next().is_none());

pub fn rchunks(&self, chunk_size: usize) -> RChunks<'_, T>

Returns an iterator over chunk_size elements of the slice at a time, starting at the end of the slice.

The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last chunk will not have length chunk_size.

See rchunks_exact for a variant of this iterator that returns chunks of always exactly chunk_size elements, and chunks for the same iterator but starting at the beginning of the slice.

Panics

Panics if chunk_size is 0.

Examples

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.rchunks(2);
assert_eq!(iter.next().unwrap(), &['e', 'm']);
assert_eq!(iter.next().unwrap(), &['o', 'r']);
assert_eq!(iter.next().unwrap(), &['l']);
assert!(iter.next().is_none());

pub fn rchunks_exact(&self, chunk_size: usize) -> RChunksExact<'_, T>

Returns an iterator over chunk_size elements of the slice at a time, starting at the end of the slice.

The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last up to chunk_size-1 elements will be omitted and can be retrieved from the remainder function of the iterator.

Due to each chunk having exactly chunk_size elements, the compiler can often optimize the resulting code better than in the case of rchunks.

See rchunks for a variant of this iterator that also returns the remainder as a smaller chunk, and chunks_exact for the same iterator but starting at the beginning of the slice.

Panics

Panics if chunk_size is 0.

Examples

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.rchunks_exact(2);
assert_eq!(iter.next().unwrap(), &['e', 'm']);
assert_eq!(iter.next().unwrap(), &['o', 'r']);
assert!(iter.next().is_none());
assert_eq!(iter.remainder(), &['l']);

pub fn chunk_by<F>(&self, pred: F) -> ChunkBy<'_, T, F>

where F: FnMut(&T, &T) -> bool,

Returns an iterator over the slice producing non-overlapping runs of elements using the predicate to separate them.

The predicate is called for every pair of consecutive elements, meaning that it is called on slice[0] and slice[1], followed by slice[1] and slice[2], and so on.

Examples

let slice = &[1, 1, 1, 3, 3, 2, 2, 2];

let mut iter = slice.chunk_by(|a, b| a == b);

assert_eq!(iter.next(), Some(&[1, 1, 1][..]));
assert_eq!(iter.next(), Some(&[3, 3][..]));
assert_eq!(iter.next(), Some(&[2, 2, 2][..]));
assert_eq!(iter.next(), None);

This method can be used to extract the sorted subslices:

let slice = &[1, 1, 2, 3, 2, 3, 2, 3, 4];

let mut iter = slice.chunk_by(|a, b| a <= b);

assert_eq!(iter.next(), Some(&[1, 1, 2, 3][..]));
assert_eq!(iter.next(), Some(&[2, 3][..]));
assert_eq!(iter.next(), Some(&[2, 3, 4][..]));
assert_eq!(iter.next(), None);

pub fn split_at(&self, mid: usize) -> (&[T], &[T])

Divides one slice into two at an index.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Panics

Panics if mid > len. For a non-panicking alternative see split_at_checked.

Examples

let v = [1, 2, 3, 4, 5, 6];

{
   let (left, right) = v.split_at(0);
   assert_eq!(left, []);
   assert_eq!(right, [1, 2, 3, 4, 5, 6]);
}

{
    let (left, right) = v.split_at(2);
    assert_eq!(left, [1, 2]);
    assert_eq!(right, [3, 4, 5, 6]);
}

{
    let (left, right) = v.split_at(6);
    assert_eq!(left, [1, 2, 3, 4, 5, 6]);
    assert_eq!(right, []);
}

pub unsafe fn split_at_unchecked(&self, mid: usize) -> (&[T], &[T])

Divides one slice into two at an index, without doing bounds checking.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

For a safe alternative see split_at.

Safety

Calling this method with an out-of-bounds index is undefined behavior even if the resulting reference is not used. The caller has to ensure that 0 <= mid <= self.len().

Examples

let v = [1, 2, 3, 4, 5, 6];

unsafe {
   let (left, right) = v.split_at_unchecked(0);
   assert_eq!(left, []);
   assert_eq!(right, [1, 2, 3, 4, 5, 6]);
}

unsafe {
    let (left, right) = v.split_at_unchecked(2);
    assert_eq!(left, [1, 2]);
    assert_eq!(right, [3, 4, 5, 6]);
}

unsafe {
    let (left, right) = v.split_at_unchecked(6);
    assert_eq!(left, [1, 2, 3, 4, 5, 6]);
    assert_eq!(right, []);
}

pub fn split_at_checked(&self, mid: usize) -> Option<(&[T], &[T])>

Divides one slice into two at an index, returning None if the slice is too short.

If mid ≤ len returns a pair of slices where the first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Otherwise, if mid > len, returns None.

Examples

let v = [1, -2, 3, -4, 5, -6];

{
   let (left, right) = v.split_at_checked(0).unwrap();
   assert_eq!(left, []);
   assert_eq!(right, [1, -2, 3, -4, 5, -6]);
}

{
    let (left, right) = v.split_at_checked(2).unwrap();
    assert_eq!(left, [1, -2]);
    assert_eq!(right, [3, -4, 5, -6]);
}

{
    let (left, right) = v.split_at_checked(6).unwrap();
    assert_eq!(left, [1, -2, 3, -4, 5, -6]);
    assert_eq!(right, []);
}

assert_eq!(None, v.split_at_checked(7));

pub fn split<F>(&self, pred: F) -> Split<'_, T, F>

where F: FnMut(&T) -> bool,

Returns an iterator over subslices separated by elements that match pred. The matched element is not contained in the subslices.

Examples

let slice = [10, 40, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

If the first element is matched, an empty slice will be the first item returned by the iterator. Similarly, if the last element in the slice is matched, an empty slice will be the last item returned by the iterator:

let slice = [10, 40, 33];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[]);
assert!(iter.next().is_none());

If two matched elements are directly adjacent, an empty slice will be present between them:

let slice = [10, 6, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10]);
assert_eq!(iter.next().unwrap(), &[]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

pub fn split_inclusive<F>(&self, pred: F) -> SplitInclusive<'_, T, F>

where F: FnMut(&T) -> bool,

Returns an iterator over subslices separated by elements that match pred. The matched element is contained in the end of the previous subslice as a terminator.

Examples

let slice = [10, 40, 33, 20];
let mut iter = slice.split_inclusive(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40, 33]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

If the last element of the slice is matched, that element will be considered the terminator of the preceding slice. That slice will be the last item returned by the iterator.

let slice = [3, 10, 40, 33];
let mut iter = slice.split_inclusive(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[3]);
assert_eq!(iter.next().unwrap(), &[10, 40, 33]);
assert!(iter.next().is_none());

pub fn rsplit<F>(&self, pred: F) -> RSplit<'_, T, F>

where F: FnMut(&T) -> bool,

Returns an iterator over subslices separated by elements that match pred, starting at the end of the slice and working backwards. The matched element is not contained in the subslices.

Examples

let slice = [11, 22, 33, 0, 44, 55];
let mut iter = slice.rsplit(|num| *num == 0);

assert_eq!(iter.next().unwrap(), &[44, 55]);
assert_eq!(iter.next().unwrap(), &[11, 22, 33]);
assert_eq!(iter.next(), None);

As with split(), if the first or last element is matched, an empty slice will be the first (or last) item returned by the iterator.

let v = &[0, 1, 1, 2, 3, 5, 8];
let mut it = v.rsplit(|n| *n % 2 == 0);
assert_eq!(it.next().unwrap(), &[]);
assert_eq!(it.next().unwrap(), &[3, 5]);
assert_eq!(it.next().unwrap(), &[1, 1]);
assert_eq!(it.next().unwrap(), &[]);
assert_eq!(it.next(), None);

pub fn splitn<F>(&self, n: usize, pred: F) -> SplitN<'_, T, F>

where F: FnMut(&T) -> bool,

Returns an iterator over subslices separated by elements that match pred, limited to returning at most n items. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once by numbers divisible by 3 (i.e., [10, 40], [20, 60, 50]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.splitn(2, |num| *num % 3 == 0) {
    println!("{group:?}");
}

pub fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<'_, T, F>

where F: FnMut(&T) -> bool,

Returns an iterator over subslices separated by elements that match pred limited to returning at most n items. This starts at the end of the slice and works backwards. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once, starting from the end, by numbers divisible by 3 (i.e., [50], [10, 40, 30, 20]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.rsplitn(2, |num| *num % 3 == 0) {
    println!("{group:?}");
}

pub fn split_once<F>(&self, pred: F) -> Option<(&[T], &[T])>

where F: FnMut(&T) -> bool,

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

Splits the slice on the first element that matches the specified predicate.

If any matching elements are present in the slice, returns the prefix before the match and suffix after. The matching element itself is not included. If no elements match, returns None.

Examples

#![feature(slice_split_once)]
let s = [1, 2, 3, 2, 4];
assert_eq!(s.split_once(|&x| x == 2), Some((
    &[1][..],
    &[3, 2, 4][..]
)));
assert_eq!(s.split_once(|&x| x == 0), None);

pub fn rsplit_once<F>(&self, pred: F) -> Option<(&[T], &[T])>

where F: FnMut(&T) -> bool,

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

Splits the slice on the last element that matches the specified predicate.

If any matching elements are present in the slice, returns the prefix before the match and suffix after. The matching element itself is not included. If no elements match, returns None.

Examples

#![feature(slice_split_once)]
let s = [1, 2, 3, 2, 4];
assert_eq!(s.rsplit_once(|&x| x == 2), Some((
    &[1, 2, 3][..],
    &[4][..]
)));
assert_eq!(s.rsplit_once(|&x| x == 0), None);

pub fn contains(&self, x: &T) -> bool

where T: PartialEq,

Returns true if the slice contains an element with the given value.

This operation is O(n).

Note that if you have a sorted slice, binary_search may be faster.

Examples

let v = [10, 40, 30];
assert!(v.contains(&30));
assert!(!v.contains(&50));

If you do not have a &T, but some other value that you can compare with one (for example, String implements PartialEq<str>), you can use iter().any:

let v = [String::from("hello"), String::from("world")]; // slice of `String`
assert!(v.iter().any(|e| e == "hello")); // search with `&str`
assert!(!v.iter().any(|e| e == "hi"));

pub fn starts_with(&self, needle: &[T]) -> bool

where T: PartialEq,

Returns true if needle is a prefix of the slice or equal to the slice.

Examples

let v = [10, 40, 30];
assert!(v.starts_with(&[10]));
assert!(v.starts_with(&[10, 40]));
assert!(v.starts_with(&v));
assert!(!v.starts_with(&[50]));
assert!(!v.starts_with(&[10, 50]));

Always returns true if needle is an empty slice:

let v = &[10, 40, 30];
assert!(v.starts_with(&[]));
let v: &[u8] = &[];
assert!(v.starts_with(&[]));

pub fn ends_with(&self, needle: &[T]) -> bool

where T: PartialEq,

Returns true if needle is a suffix of the slice or equal to the slice.

Examples

let v = [10, 40, 30];
assert!(v.ends_with(&[30]));
assert!(v.ends_with(&[40, 30]));
assert!(v.ends_with(&v));
assert!(!v.ends_with(&[50]));
assert!(!v.ends_with(&[50, 30]));

Always returns true if needle is an empty slice:

let v = &[10, 40, 30];
assert!(v.ends_with(&[]));
let v: &[u8] = &[];
assert!(v.ends_with(&[]));

pub fn strip_prefix<P>(&self, prefix: &P) -> Option<&[T]>

where P: SlicePattern<Item = T> + ?Sized, T: PartialEq,

Returns a subslice with the prefix removed.

If the slice starts with prefix, returns the subslice after the prefix, wrapped in Some. If prefix is empty, simply returns the original slice. If prefix is equal to the original slice, returns an empty slice.

If the slice does not start with prefix, returns None.

Examples

let v = &[10, 40, 30];
assert_eq!(v.strip_prefix(&[10]), Some(&[40, 30][..]));
assert_eq!(v.strip_prefix(&[10, 40]), Some(&[30][..]));
assert_eq!(v.strip_prefix(&[10, 40, 30]), Some(&[][..]));
assert_eq!(v.strip_prefix(&[50]), None);
assert_eq!(v.strip_prefix(&[10, 50]), None);

let prefix : &str = "he";
assert_eq!(b"hello".strip_prefix(prefix.as_bytes()),
           Some(b"llo".as_ref()));

pub fn strip_suffix<P>(&self, suffix: &P) -> Option<&[T]>

where P: SlicePattern<Item = T> + ?Sized, T: PartialEq,

Returns a subslice with the suffix removed.

If the slice ends with suffix, returns the subslice before the suffix, wrapped in Some. If suffix is empty, simply returns the original slice. If suffix is equal to the original slice, returns an empty slice.

If the slice does not end with suffix, returns None.

Examples

let v = &[10, 40, 30];
assert_eq!(v.strip_suffix(&[30]), Some(&[10, 40][..]));
assert_eq!(v.strip_suffix(&[40, 30]), Some(&[10][..]));
assert_eq!(v.strip_suffix(&[10, 40, 30]), Some(&[][..]));
assert_eq!(v.strip_suffix(&[50]), None);
assert_eq!(v.strip_suffix(&[50, 30]), None);

pub fn binary_search(&self, x: &T) -> Result<usize, usize>

where T: Ord,

Binary searches this slice for a given element. If the slice is not sorted, the returned result is unspecified and meaningless.

If the value is found then Result::Ok is returned, containing the index of the matching element. If there are multiple matches, then any one of the matches could be returned. The index is chosen deterministically, but is subject to change in future versions of Rust. If the value is not found then Result::Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

See also binary_search_by, binary_search_by_key, and partition_point.

Examples

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

assert_eq!(s.binary_search(&13),  Ok(9));
assert_eq!(s.binary_search(&4),   Err(7));
assert_eq!(s.binary_search(&100), Err(13));
let r = s.binary_search(&1);
assert!(match r { Ok(1..=4) => true, _ => false, });

If you want to find that whole range of matching items, rather than an arbitrary matching one, that can be done using partition_point:

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

let low = s.partition_point(|x| x < &1);
assert_eq!(low, 1);
let high = s.partition_point(|x| x <= &1);
assert_eq!(high, 5);
let r = s.binary_search(&1);
assert!((low..high).contains(&r.unwrap()));

assert!(s[..low].iter().all(|&x| x < 1));
assert!(s[low..high].iter().all(|&x| x == 1));
assert!(s[high..].iter().all(|&x| x > 1));

// For something not found, the "range" of equal items is empty
assert_eq!(s.partition_point(|x| x < &11), 9);
assert_eq!(s.partition_point(|x| x <= &11), 9);
assert_eq!(s.binary_search(&11), Err(9));

If you want to insert an item to a sorted vector, while maintaining sort order, consider using partition_point:

let mut s = vec![0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];
let num = 42;
let idx = s.partition_point(|&x| x <= num);
// If `num` is unique, `s.partition_point(|&x| x < num)` (with `<`) is equivalent to
// `s.binary_search(&num).unwrap_or_else(|x| x)`, but using `<=` will allow `insert`
// to shift less elements.
s.insert(idx, num);
assert_eq!(s, [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 42, 55]);

pub fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize>

where F: FnMut(&'a T) -> Ordering,

Binary searches this slice with a comparator function.

The comparator function should return an order code that indicates whether its argument is Less, Equal or Greater the desired target. If the slice is not sorted or if the comparator function does not implement an order consistent with the sort order of the underlying slice, the returned result is unspecified and meaningless.

If the value is found then Result::Ok is returned, containing the index of the matching element. If there are multiple matches, then any one of the matches could be returned. The index is chosen deterministically, but is subject to change in future versions of Rust. If the value is not found then Result::Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

See also binary_search, binary_search_by_key, and partition_point.

Examples

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

let seek = 13;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Ok(9));
let seek = 4;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(7));
let seek = 100;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(13));
let seek = 1;
let r = s.binary_search_by(|probe| probe.cmp(&seek));
assert!(match r { Ok(1..=4) => true, _ => false, });

pub fn binary_search_by_key<'a, B, F>( &'a self, b: &B, f: F, ) -> Result<usize, usize>

where F: FnMut(&'a T) -> B, B: Ord,

Binary searches this slice with a key extraction function.

Assumes that the slice is sorted by the key, for instance with sort_by_key using the same key extraction function. If the slice is not sorted by the key, the returned result is unspecified and meaningless.

If the value is found then Result::Ok is returned, containing the index of the matching element. If there are multiple matches, then any one of the matches could be returned. The index is chosen deterministically, but is subject to change in future versions of Rust. If the value is not found then Result::Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

See also binary_search, binary_search_by, and partition_point.

Examples

Looks up a series of four elements in a slice of pairs sorted by their second elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [(0, 0), (2, 1), (4, 1), (5, 1), (3, 1),
         (1, 2), (2, 3), (4, 5), (5, 8), (3, 13),
         (1, 21), (2, 34), (4, 55)];

assert_eq!(s.binary_search_by_key(&13, |&(a, b)| b),  Ok(9));
assert_eq!(s.binary_search_by_key(&4, |&(a, b)| b),   Err(7));
assert_eq!(s.binary_search_by_key(&100, |&(a, b)| b), Err(13));
let r = s.binary_search_by_key(&1, |&(a, b)| b);
assert!(match r { Ok(1..=4) => true, _ => false, });

pub unsafe fn align_to<U>(&self) -> (&[T], &[U], &[T])

Transmute the slice to a slice of another type, ensuring alignment of the types is maintained.

This method splits the slice into three distinct slices: prefix, correctly aligned middle slice of a new type, and the suffix slice. The middle part will be as big as possible under the given alignment constraint and element size.

This method has no purpose when either input element T or output element U are zero-sized and will return the original slice without splitting anything.

Safety

This method is essentially a transmute with respect to the elements in the returned middle slice, so all the usual caveats pertaining to transmute::<T, U> also apply here.

Examples

Basic usage:

unsafe {
    let bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7];
    let (prefix, shorts, suffix) = bytes.align_to::<u16>();
    // less_efficient_algorithm_for_bytes(prefix);
    // more_efficient_algorithm_for_aligned_shorts(shorts);
    // less_efficient_algorithm_for_bytes(suffix);
}

pub fn as_simd<const LANES: usize>(&self) -> (&[T], &[Simd<T, LANES>], &[T])

where Simd<T, LANES>: AsRef<[T; LANES]>, T: SimdElement, LaneCount<LANES>: SupportedLaneCount,

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

Split a slice into a prefix, a middle of aligned SIMD types, and a suffix.

This is a safe wrapper around slice::align_to, so inherits the same guarantees as that method.

Panics

This will panic if the size of the SIMD type is different from LANES times that of the scalar.

At the time of writing, the trait restrictions on Simd<T, LANES> keeps that from ever happening, as only power-of-two numbers of lanes are supported. It’s possible that, in the future, those restrictions might be lifted in a way that would make it possible to see panics from this method for something like LANES == 3.

Examples

#![feature(portable_simd)]
use core::simd::prelude::*;

let short = &[1, 2, 3];
let (prefix, middle, suffix) = short.as_simd::<4>();
assert_eq!(middle, []); // Not enough elements for anything in the middle

// They might be split in any possible way between prefix and suffix
let it = prefix.iter().chain(suffix).copied();
assert_eq!(it.collect::<Vec<_>>(), vec![1, 2, 3]);

fn basic_simd_sum(x: &[f32]) -> f32 {
    use std::ops::Add;
    let (prefix, middle, suffix) = x.as_simd();
    let sums = f32x4::from_array([
        prefix.iter().copied().sum(),
        0.0,
        0.0,
        suffix.iter().copied().sum(),
    ]);
    let sums = middle.iter().copied().fold(sums, f32x4::add);
    sums.reduce_sum()
}

let numbers: Vec<f32> = (1..101).map(|x| x as _).collect();
assert_eq!(basic_simd_sum(&numbers[1..99]), 4949.0);

pub fn is_sorted(&self) -> bool

where T: PartialOrd,

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

Checks if the elements of this slice are sorted.

That is, for each element a and its following element b, a <= b must hold. If the slice yields exactly zero or one element, true is returned.

Note that if Self::Item is only PartialOrd, but not Ord, the above definition implies that this function returns false if any two consecutive items are not comparable.

Examples

#![feature(is_sorted)]
let empty: [i32; 0] = [];

assert!([1, 2, 2, 9].is_sorted());
assert!(![1, 3, 2, 4].is_sorted());
assert!([0].is_sorted());
assert!(empty.is_sorted());
assert!(![0.0, 1.0, f32::NAN].is_sorted());

pub fn is_sorted_by<'a, F>(&'a self, compare: F) -> bool

where F: FnMut(&'a T, &'a T) -> bool,

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

Checks if the elements of this slice are sorted using the given comparator function.

Instead of using PartialOrd::partial_cmp, this function uses the given compare function to determine whether two elements are to be considered in sorted order.

Examples

#![feature(is_sorted)]

assert!([1, 2, 2, 9].is_sorted_by(|a, b| a <= b));
assert!(![1, 2, 2, 9].is_sorted_by(|a, b| a < b));

assert!([0].is_sorted_by(|a, b| true));
assert!([0].is_sorted_by(|a, b| false));

let empty: [i32; 0] = [];
assert!(empty.is_sorted_by(|a, b| false));
assert!(empty.is_sorted_by(|a, b| true));

pub fn is_sorted_by_key<'a, F, K>(&'a self, f: F) -> bool

where F: FnMut(&'a T) -> K, K: PartialOrd,

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

Checks if the elements of this slice are sorted using the given key extraction function.

Instead of comparing the slice’s elements directly, this function compares the keys of the elements, as determined by f. Apart from that, it’s equivalent to is_sorted; see its documentation for more information.

Examples

#![feature(is_sorted)]

assert!(["c", "bb", "aaa"].is_sorted_by_key(|s| s.len()));
assert!(![-2i32, -1, 0, 3].is_sorted_by_key(|n| n.abs()));

pub fn partition_point<P>(&self, pred: P) -> usize

where P: FnMut(&T) -> bool,

Returns the index of the partition point according to the given predicate (the index of the first element of the second partition).

The slice is assumed to be partitioned according to the given predicate. This means that all elements for which the predicate returns true are at the start of the slice and all elements for which the predicate returns false are at the end. For example, [7, 15, 3, 5, 4, 12, 6] is partitioned under the predicate x % 2 != 0 (all odd numbers are at the start, all even at the end).

If this slice is not partitioned, the returned result is unspecified and meaningless, as this method performs a kind of binary search.

See also binary_search, binary_search_by, and binary_search_by_key.

Examples

let v = [1, 2, 3, 3, 5, 6, 7];
let i = v.partition_point(|&x| x < 5);

assert_eq!(i, 4);
assert!(v[..i].iter().all(|&x| x < 5));
assert!(v[i..].iter().all(|&x| !(x < 5)));

If all elements of the slice match the predicate, including if the slice is empty, then the length of the slice will be returned:

let a = [2, 4, 8];
assert_eq!(a.partition_point(|x| x < &100), a.len());
let a: [i32; 0] = [];
assert_eq!(a.partition_point(|x| x < &100), 0);

If you want to insert an item to a sorted vector, while maintaining sort order:

let mut s = vec![0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];
let num = 42;
let idx = s.partition_point(|&x| x <= num);
s.insert(idx, num);
assert_eq!(s, [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 42, 55]);

pub fn utf8_chunks(&self) -> Utf8Chunks<'_>

Creates an iterator over the contiguous valid UTF-8 ranges of this slice, and the non-UTF-8 fragments in between.

Examples

This function formats arbitrary but mostly-UTF-8 bytes into Rust source code in the form of a C-string literal (c"...").

use std::fmt::Write as _;

pub fn cstr_literal(bytes: &[u8]) -> String {
    let mut repr = String::new();
    repr.push_str("c\"");
    for chunk in bytes.utf8_chunks() {
        for ch in chunk.valid().chars() {
            // Escapes \0, \t, \r, \n, \\, \', \", and uses \u{...} for non-printable characters.
            write!(repr, "{}", ch.escape_debug()).unwrap();
        }
        for byte in chunk.invalid() {
            write!(repr, "\\x{:02X}", byte).unwrap();
        }
    }
    repr.push('"');
    repr
}

fn main() {
    let lit = cstr_literal(b"\xferris the \xf0\x9f\xa6\x80\x07");
    let expected = stringify!(c"\xFErris the 🦀\u{7}");
    assert_eq!(lit, expected);
}

pub fn is_ascii(&self) -> bool

Checks if all bytes in this slice are within the ASCII range.

pub fn as_ascii(&self) -> Option<&[AsciiChar]>

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

If this slice is_ascii, returns it as a slice of ASCII characters, otherwise returns None.

pub unsafe fn as_ascii_unchecked(&self) -> &[AsciiChar]

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

Converts this slice of bytes into a slice of ASCII characters, without checking whether they’re valid.

Safety

Every byte in the slice must be in 0..=127, or else this is UB.

pub fn eq_ignore_ascii_case(&self, other: &[u8]) -> bool

Checks that two slices are an ASCII case-insensitive match.

Same as to_ascii_lowercase(a) == to_ascii_lowercase(b), but without allocating and copying temporaries.

pub fn escape_ascii(&self) -> EscapeAscii<'_>

Returns an iterator that produces an escaped version of this slice, treating it as an ASCII string.

Examples

let s = b"0\t\r\n'\"\\\x9d";
let escaped = s.escape_ascii().to_string();
assert_eq!(escaped, "0\\t\\r\\n\\'\\\"\\\\\\x9d");

pub fn trim_ascii_start(&self) -> &[u8]

Returns a byte slice with leading ASCII whitespace bytes removed.

‘Whitespace’ refers to the definition used by u8::is_ascii_whitespace.

Examples

assert_eq!(b" \t hello world\n".trim_ascii_start(), b"hello world\n");
assert_eq!(b"  ".trim_ascii_start(), b"");
assert_eq!(b"".trim_ascii_start(), b"");

pub fn trim_ascii_end(&self) -> &[u8]

Returns a byte slice with trailing ASCII whitespace bytes removed.

‘Whitespace’ refers to the definition used by u8::is_ascii_whitespace.

Examples

assert_eq!(b"\r hello world\n ".trim_ascii_end(), b"\r hello world");
assert_eq!(b"  ".trim_ascii_end(), b"");
assert_eq!(b"".trim_ascii_end(), b"");

pub fn trim_ascii(&self) -> &[u8]

Returns a byte slice with leading and trailing ASCII whitespace bytes removed.

‘Whitespace’ refers to the definition used by u8::is_ascii_whitespace.

Examples

assert_eq!(b"\r hello world\n ".trim_ascii(), b"hello world");
assert_eq!(b"  ".trim_ascii(), b"");
assert_eq!(b"".trim_ascii(), b"");

pub fn as_flattened(&self) -> &[T]

Takes a &[[T; N]], and flattens it to a &[T].

Panics

This panics if the length of the resulting slice would overflow a usize.

This is only possible when flattening a slice of arrays of zero-sized types, and thus tends to be irrelevant in practice. If size_of::<T>() > 0, this will never panic.

Examples

assert_eq!([[1, 2, 3], [4, 5, 6]].as_flattened(), &[1, 2, 3, 4, 5, 6]);

assert_eq!(
    [[1, 2, 3], [4, 5, 6]].as_flattened(),
    [[1, 2], [3, 4], [5, 6]].as_flattened(),
);

let slice_of_empty_arrays: &[[i32; 0]] = &[[], [], [], [], []];
assert!(slice_of_empty_arrays.as_flattened().is_empty());

let empty_slice_of_arrays: &[[u32; 10]] = &[];
assert!(empty_slice_of_arrays.as_flattened().is_empty());

pub fn as_str(&self) -> &str

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

Views this slice of ASCII characters as a UTF-8 str.

pub fn as_bytes(&self) -> &[u8]

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

Views this slice of ASCII characters as a slice of u8 bytes.

pub fn to_ascii_uppercase(&self) -> Vec<u8>

Returns a vector containing a copy of this slice where each byte is mapped to its ASCII upper case equivalent.

ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.

To uppercase the value in-place, use make_ascii_uppercase.

pub fn to_ascii_lowercase(&self) -> Vec<u8>

Returns a vector containing a copy of this slice where each byte is mapped to its ASCII lower case equivalent.

ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.

To lowercase the value in-place, use make_ascii_lowercase.

pub fn to_vec(&self) -> Vec<T>

where T: Clone,

Copies self into a new Vec.

Examples

let s = [10, 40, 30];
let x = s.to_vec();
// Here, `s` and `x` can be modified independently.

pub fn to_vec_in<A>(&self, alloc: A) -> Vec<T, A>

where A: Allocator, T: Clone,

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

Copies self into a new Vec with an allocator.

Examples

#![feature(allocator_api)]

use std::alloc::System;

let s = [10, 40, 30];
let x = s.to_vec_in(System);
// Here, `s` and `x` can be modified independently.

pub fn repeat(&self, n: usize) -> Vec<T>

where T: Copy,

Creates a vector by copying a slice n times.

Panics

This function will panic if the capacity would overflow.

Examples

Basic usage:

assert_eq!([1, 2].repeat(3), vec![1, 2, 1, 2, 1, 2]);

A panic upon overflow:

// this will panic at runtime
b"0123456789abcdef".repeat(usize::MAX);

pub fn concat<Item>(&self) -> <[T] as Concat<Item>>::Output

where [T]: Concat<Item>, Item: ?Sized,

Flattens a slice of T into a single value Self::Output.

Examples

assert_eq!(["hello", "world"].concat(), "helloworld");
assert_eq!([[1, 2], [3, 4]].concat(), [1, 2, 3, 4]);

pub fn join<Separator>( &self, sep: Separator, ) -> <[T] as Join<Separator>>::Output

where [T]: Join<Separator>,

Flattens a slice of T into a single value Self::Output, placing a given separator between each.

Examples

assert_eq!(["hello", "world"].join(" "), "hello world");
assert_eq!([[1, 2], [3, 4]].join(&0), [1, 2, 0, 3, 4]);
assert_eq!([[1, 2], [3, 4]].join(&[0, 0][..]), [1, 2, 0, 0, 3, 4]);

pub fn connect<Separator>( &self, sep: Separator, ) -> <[T] as Join<Separator>>::Output

where [T]: Join<Separator>,

👎Deprecated since 1.3.0: renamed to join

Flattens a slice of T into a single value Self::Output, placing a given separator between each.

Examples

assert_eq!(["hello", "world"].connect(" "), "hello world");
assert_eq!([[1, 2], [3, 4]].connect(&0), [1, 2, 0, 3, 4]);

Trait Implementations

impl<E: Clone + Element> Clone for VecStore<E>

fn clone(&self) -> VecStore<E>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<E: Debug + Element> Debug for VecStore<E>

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

Formats the value using the given formatter.

impl<E: Default + Element> Default for VecStore<E>

fn default() -> VecStore<E>

Returns the “default value” for a type.

impl<E: Element> Deref for VecStore<E>

type Target = [E]

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<'a, E: Element> IndexedParallelIterator for &'a VecStore<E>

fn drive<C>(self, consumer: C) -> C::Result

where C: Consumer<Self::Item>,

Internal method used to define the behavior of this parallel iterator. You should not need to call this directly.

fn len(&self) -> usize

Produces an exact count of how many items this iterator will produce, presuming no panic occurs.

fn with_producer<CB>(self, callback: CB) -> CB::Output

where CB: ProducerCallback<Self::Item>,

Internal method used to define the behavior of this parallel iterator. You should not need to call this directly.

fn by_exponential_blocks(self) -> ExponentialBlocks<Self>

Divides an iterator into sequential blocks of exponentially-increasing size.

fn by_uniform_blocks(self, block_size: usize) -> UniformBlocks<Self>

Divides an iterator into sequential blocks of the given size.

fn collect_into_vec(self, target: &mut Vec<Self::Item>)

Collects the results of the iterator into the specified vector. The vector is always cleared before execution begins. If possible, reusing the vector across calls can lead to better performance since it reuses the same backing buffer.

fn unzip_into_vecs<A, B>(self, left: &mut Vec<A>, right: &mut Vec<B>)

where Self: IndexedParallelIterator<Item = (A, B)>, A: Send, B: Send,

Unzips the results of the iterator into the specified vectors. The vectors are always cleared before execution begins. If possible, reusing the vectors across calls can lead to better performance since they reuse the same backing buffer.

fn zip<Z>(self, zip_op: Z) -> Zip<Self, <Z as IntoParallelIterator>::Iter>

where Z: IntoParallelIterator, <Z as IntoParallelIterator>::Iter: IndexedParallelIterator,

Iterates over tuples (A, B), where the items A are from this iterator and B are from the iterator given as argument. Like the zip method on ordinary iterators, if the two iterators are of unequal length, you only get the items they have in common.

fn zip_eq<Z>(self, zip_op: Z) -> ZipEq<Self, <Z as IntoParallelIterator>::Iter>

where Z: IntoParallelIterator, <Z as IntoParallelIterator>::Iter: IndexedParallelIterator,

The same as Zip, but requires that both iterators have the same length.

fn interleave<I>( self, other: I, ) -> Interleave<Self, <I as IntoParallelIterator>::Iter>

where I: IntoParallelIterator<Item = Self::Item>, <I as IntoParallelIterator>::Iter: IndexedParallelIterator<Item = Self::Item>,

Interleaves elements of this iterator and the other given iterator. Alternately yields elements from this iterator and the given iterator, until both are exhausted. If one iterator is exhausted before the other, the last elements are provided from the other.

fn interleave_shortest<I>( self, other: I, ) -> InterleaveShortest<Self, <I as IntoParallelIterator>::Iter>

where I: IntoParallelIterator<Item = Self::Item>, <I as IntoParallelIterator>::Iter: IndexedParallelIterator<Item = Self::Item>,

Interleaves elements of this iterator and the other given iterator, until one is exhausted.

fn chunks(self, chunk_size: usize) -> Chunks<Self>

Splits an iterator up into fixed-size chunks.

fn fold_chunks<T, ID, F>( self, chunk_size: usize, identity: ID, fold_op: F, ) -> FoldChunks<Self, ID, F>

where ID: Fn() -> T + Send + Sync, F: Fn(T, Self::Item) -> T + Send + Sync, T: Send,

Splits an iterator into fixed-size chunks, performing a sequential fold() on each chunk.

fn fold_chunks_with<T, F>( self, chunk_size: usize, init: T, fold_op: F, ) -> FoldChunksWith<Self, T, F>

where T: Send + Clone, F: Fn(T, Self::Item) -> T + Send + Sync,

Splits an iterator into fixed-size chunks, performing a sequential fold() on each chunk.

fn partial_cmp<I>(self, other: I) -> Option<Ordering>

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialOrd<<I as IntoParallelIterator>::Item>,

Lexicographically compares the elements of this ParallelIterator with those of another.

fn eq<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialEq<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are equal to those of another

fn ne<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialEq<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are unequal to those of another

fn lt<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialOrd<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are lexicographically less than those of another.

fn le<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialOrd<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are less or equal to those of another.

fn gt<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialOrd<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are lexicographically greater than those of another.

fn ge<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialOrd<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are less or equal to those of another.

fn enumerate(self) -> Enumerate<Self>

Yields an index along with each item.

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

Creates an iterator that steps by the given amount

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

Creates an iterator that skips the first n elements.

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

Creates an iterator that yields the first n elements.

fn position_any<P>(self, predicate: P) -> Option<usize>

where P: Fn(Self::Item) -> bool + Sync + Send,

Searches for some item in the parallel iterator that matches the given predicate, and returns its index. Like ParallelIterator::find_any, the parallel search will not necessarily find the first match, and once a match is found we’ll attempt to stop processing any more.

fn position_first<P>(self, predicate: P) -> Option<usize>

where P: Fn(Self::Item) -> bool + Sync + Send,

Searches for the sequentially first item in the parallel iterator that matches the given predicate, and returns its index.

fn position_last<P>(self, predicate: P) -> Option<usize>

where P: Fn(Self::Item) -> bool + Sync + Send,

Searches for the sequentially last item in the parallel iterator that matches the given predicate, and returns its index.

fn positions<P>(self, predicate: P) -> Positions<Self, P>

where P: Fn(Self::Item) -> bool + Sync + Send,

Searches for items in the parallel iterator that match the given predicate, and returns their indices.

fn rev(self) -> Rev<Self>

Produces a new iterator with the elements of this iterator in reverse order.

fn with_min_len(self, min: usize) -> MinLen<Self>

Sets the minimum length of iterators desired to process in each rayon job. Rayon will not split any smaller than this length, but of course an iterator could already be smaller to begin with.

fn with_max_len(self, max: usize) -> MaxLen<Self>

Sets the maximum length of iterators desired to process in each rayon job. Rayon will try to split at least below this length, unless that would put it below the length from with_min_len(). For example, given min=10 and max=15, a length of 16 will not be split any further.

impl<E: Element> IndexedParallelIterator for VecStore<E>

fn drive<C>(self, consumer: C) -> C::Result

where C: Consumer<Self::Item>,

Internal method used to define the behavior of this parallel iterator. You should not need to call this directly.

fn len(&self) -> usize

Produces an exact count of how many items this iterator will produce, presuming no panic occurs.

fn with_producer<CB>(self, callback: CB) -> CB::Output

where CB: ProducerCallback<Self::Item>,

Internal method used to define the behavior of this parallel iterator. You should not need to call this directly.

fn by_exponential_blocks(self) -> ExponentialBlocks<Self>

Divides an iterator into sequential blocks of exponentially-increasing size.

fn by_uniform_blocks(self, block_size: usize) -> UniformBlocks<Self>

Divides an iterator into sequential blocks of the given size.

fn collect_into_vec(self, target: &mut Vec<Self::Item>)

Collects the results of the iterator into the specified vector. The vector is always cleared before execution begins. If possible, reusing the vector across calls can lead to better performance since it reuses the same backing buffer.

fn unzip_into_vecs<A, B>(self, left: &mut Vec<A>, right: &mut Vec<B>)

where Self: IndexedParallelIterator<Item = (A, B)>, A: Send, B: Send,

Unzips the results of the iterator into the specified vectors. The vectors are always cleared before execution begins. If possible, reusing the vectors across calls can lead to better performance since they reuse the same backing buffer.

fn zip<Z>(self, zip_op: Z) -> Zip<Self, <Z as IntoParallelIterator>::Iter>

where Z: IntoParallelIterator, <Z as IntoParallelIterator>::Iter: IndexedParallelIterator,

Iterates over tuples (A, B), where the items A are from this iterator and B are from the iterator given as argument. Like the zip method on ordinary iterators, if the two iterators are of unequal length, you only get the items they have in common.

fn zip_eq<Z>(self, zip_op: Z) -> ZipEq<Self, <Z as IntoParallelIterator>::Iter>

where Z: IntoParallelIterator, <Z as IntoParallelIterator>::Iter: IndexedParallelIterator,

The same as Zip, but requires that both iterators have the same length.

fn interleave<I>( self, other: I, ) -> Interleave<Self, <I as IntoParallelIterator>::Iter>

where I: IntoParallelIterator<Item = Self::Item>, <I as IntoParallelIterator>::Iter: IndexedParallelIterator<Item = Self::Item>,

Interleaves elements of this iterator and the other given iterator. Alternately yields elements from this iterator and the given iterator, until both are exhausted. If one iterator is exhausted before the other, the last elements are provided from the other.

fn interleave_shortest<I>( self, other: I, ) -> InterleaveShortest<Self, <I as IntoParallelIterator>::Iter>

where I: IntoParallelIterator<Item = Self::Item>, <I as IntoParallelIterator>::Iter: IndexedParallelIterator<Item = Self::Item>,

Interleaves elements of this iterator and the other given iterator, until one is exhausted.

fn chunks(self, chunk_size: usize) -> Chunks<Self>

Splits an iterator up into fixed-size chunks.

fn fold_chunks<T, ID, F>( self, chunk_size: usize, identity: ID, fold_op: F, ) -> FoldChunks<Self, ID, F>

where ID: Fn() -> T + Send + Sync, F: Fn(T, Self::Item) -> T + Send + Sync, T: Send,

Splits an iterator into fixed-size chunks, performing a sequential fold() on each chunk.

fn fold_chunks_with<T, F>( self, chunk_size: usize, init: T, fold_op: F, ) -> FoldChunksWith<Self, T, F>

where T: Send + Clone, F: Fn(T, Self::Item) -> T + Send + Sync,

Splits an iterator into fixed-size chunks, performing a sequential fold() on each chunk.

fn partial_cmp<I>(self, other: I) -> Option<Ordering>

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialOrd<<I as IntoParallelIterator>::Item>,

Lexicographically compares the elements of this ParallelIterator with those of another.

fn eq<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialEq<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are equal to those of another

fn ne<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialEq<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are unequal to those of another

fn lt<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialOrd<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are lexicographically less than those of another.

fn le<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialOrd<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are less or equal to those of another.

fn gt<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialOrd<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are lexicographically greater than those of another.

fn ge<I>(self, other: I) -> bool

where I: IntoParallelIterator, <I as IntoParallelIterator>::Iter: IndexedParallelIterator, Self::Item: PartialOrd<<I as IntoParallelIterator>::Item>,

Determines if the elements of this ParallelIterator are less or equal to those of another.

fn enumerate(self) -> Enumerate<Self>

Yields an index along with each item.

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

Creates an iterator that steps by the given amount

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

Creates an iterator that skips the first n elements.

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

Creates an iterator that yields the first n elements.

fn position_any<P>(self, predicate: P) -> Option<usize>

where P: Fn(Self::Item) -> bool + Sync + Send,

Searches for some item in the parallel iterator that matches the given predicate, and returns its index. Like ParallelIterator::find_any, the parallel search will not necessarily find the first match, and once a match is found we’ll attempt to stop processing any more.

fn position_first<P>(self, predicate: P) -> Option<usize>

where P: Fn(Self::Item) -> bool + Sync + Send,

Searches for the sequentially first item in the parallel iterator that matches the given predicate, and returns its index.

fn position_last<P>(self, predicate: P) -> Option<usize>

where P: Fn(Self::Item) -> bool + Sync + Send,

Searches for the sequentially last item in the parallel iterator that matches the given predicate, and returns its index.

fn positions<P>(self, predicate: P) -> Positions<Self, P>

where P: Fn(Self::Item) -> bool + Sync + Send,

Searches for items in the parallel iterator that match the given predicate, and returns their indices.

fn rev(self) -> Rev<Self>

Produces a new iterator with the elements of this iterator in reverse order.

fn with_min_len(self, min: usize) -> MinLen<Self>

Sets the minimum length of iterators desired to process in each rayon job. Rayon will not split any smaller than this length, but of course an iterator could already be smaller to begin with.

fn with_max_len(self, max: usize) -> MaxLen<Self>

Sets the maximum length of iterators desired to process in each rayon job. Rayon will try to split at least below this length, unless that would put it below the length from with_min_len(). For example, given min=10 and max=15, a length of 16 will not be split any further.

impl<'a, E: Element> ParallelIterator for &'a VecStore<E>

type Item = E

The type of item that this parallel iterator produces. For example, if you use the for_each method, this is the type of item that your closure will be invoked with.

fn drive_unindexed<C>(self, consumer: C) -> C::Result

where C: UnindexedConsumer<Self::Item>,

Internal method used to define the behavior of this parallel iterator. You should not need to call this directly.

fn opt_len(&self) -> Option<usize>

Internal method used to define the behavior of this parallel iterator. You should not need to call this directly.

fn for_each<OP>(self, op: OP)

where OP: Fn(Self::Item) + Sync + Send,

Executes OP on each item produced by the iterator, in parallel.

fn for_each_with<OP, T>(self, init: T, op: OP)

where OP: Fn(&mut T, Self::Item) + Sync + Send, T: Send + Clone,

Executes OP on the given init value with each item produced by the iterator, in parallel.

fn for_each_init<OP, INIT, T>(self, init: INIT, op: OP)

where OP: Fn(&mut T, Self::Item) + Sync + Send, INIT: Fn() -> T + Sync + Send,

Executes OP on a value returned by init with each item produced by the iterator, in parallel.

fn try_for_each<OP, R>(self, op: OP) -> R

where OP: Fn(Self::Item) -> R + Sync + Send, R: Try<Output = ()> + Send,

Executes a fallible OP on each item produced by the iterator, in parallel.

fn try_for_each_with<OP, T, R>(self, init: T, op: OP) -> R

where OP: Fn(&mut T, Self::Item) -> R + Sync + Send, T: Send + Clone, R: Try<Output = ()> + Send,

Executes a fallible OP on the given init value with each item produced by the iterator, in parallel.

fn try_for_each_init<OP, INIT, T, R>(self, init: INIT, op: OP) -> R

where OP: Fn(&mut T, Self::Item) -> R + Sync + Send, INIT: Fn() -> T + Sync + Send, R: Try<Output = ()> + Send,

Executes a fallible OP on a value returned by init with each item produced by the iterator, in parallel.

fn count(self) -> usize

Counts the number of items in this parallel iterator.

fn map<F, R>(self, map_op: F) -> Map<Self, F>

where F: Fn(Self::Item) -> R + Sync + Send, R: Send,

Applies map_op to each item of this iterator, producing a new iterator with the results.

fn map_with<F, T, R>(self, init: T, map_op: F) -> MapWith<Self, T, F>

where F: Fn(&mut T, Self::Item) -> R + Sync + Send, T: Send + Clone, R: Send,

Applies map_op to the given init value with each item of this iterator, producing a new iterator with the results.

fn map_init<F, INIT, T, R>( self, init: INIT, map_op: F, ) -> MapInit<Self, INIT, F>

where F: Fn(&mut T, Self::Item) -> R + Sync + Send, INIT: Fn() -> T + Sync + Send, R: Send,

Applies map_op to a value returned by init with each item of this iterator, producing a new iterator with the results.

fn cloned<'a, T>(self) -> Cloned<Self>

where T: 'a + Clone + Send, Self: ParallelIterator<Item = &'a T>,

Creates an iterator which clones all of its elements. This may be useful when you have an iterator over &T, but you need T, and that type implements Clone. See also copied().

fn copied<'a, T>(self) -> Copied<Self>

where T: 'a + Copy + Send, Self: ParallelIterator<Item = &'a T>,

Creates an iterator which copies all of its elements. This may be useful when you have an iterator over &T, but you need T, and that type implements Copy. See also cloned().

fn inspect<OP>(self, inspect_op: OP) -> Inspect<Self, OP>

where OP: Fn(&Self::Item) + Sync + Send,

Applies inspect_op to a reference to each item of this iterator, producing a new iterator passing through the original items. This is often useful for debugging to see what’s happening in iterator stages.

fn update<F>(self, update_op: F) -> Update<Self, F>

where F: Fn(&mut Self::Item) + Sync + Send,

Mutates each item of this iterator before yielding it.

fn filter<P>(self, filter_op: P) -> Filter<Self, P>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Applies filter_op to each item of this iterator, producing a new iterator with only the items that gave true results.

fn filter_map<P, R>(self, filter_op: P) -> FilterMap<Self, P>

where P: Fn(Self::Item) -> Option<R> + Sync + Send, R: Send,

Applies filter_op to each item of this iterator to get an Option, producing a new iterator with only the items from Some results.

fn flat_map<F, PI>(self, map_op: F) -> FlatMap<Self, F>

where F: Fn(Self::Item) -> PI + Sync + Send, PI: IntoParallelIterator,

Applies map_op to each item of this iterator to get nested parallel iterators, producing a new parallel iterator that flattens these back into one.

fn flat_map_iter<F, SI>(self, map_op: F) -> FlatMapIter<Self, F>

where F: Fn(Self::Item) -> SI + Sync + Send, SI: IntoIterator, <SI as IntoIterator>::Item: Send,

Applies map_op to each item of this iterator to get nested serial iterators, producing a new parallel iterator that flattens these back into one.

fn reduce<OP, ID>(self, identity: ID, op: OP) -> Self::Item

where OP: Fn(Self::Item, Self::Item) -> Self::Item + Sync + Send, ID: Fn() -> Self::Item + Sync + Send,

Reduces the items in the iterator into one item using op. The argument identity should be a closure that can produce “identity” value which may be inserted into the sequence as needed to create opportunities for parallel execution. So, for example, if you are doing a summation, then identity() ought to produce something that represents the zero for your type (but consider just calling sum() in that case).

fn reduce_with<OP>(self, op: OP) -> Option<Self::Item>

where OP: Fn(Self::Item, Self::Item) -> Self::Item + Sync + Send,

Reduces the items in the iterator into one item using op. If the iterator is empty, None is returned; otherwise, Some is returned.

fn fold<T, ID, F>(self, identity: ID, fold_op: F) -> Fold<Self, ID, F>

where F: Fn(T, Self::Item) -> T + Sync + Send, ID: Fn() -> T + Sync + Send, T: Send,

Parallel fold is similar to sequential fold except that the sequence of items may be subdivided before it is folded. Consider a list of numbers like 22 3 77 89 46. If you used sequential fold to add them (fold(0, |a,b| a+b), you would wind up first adding 0 + 22, then 22 + 3, then 25 + 77, and so forth. The parallel fold works similarly except that it first breaks up your list into sublists, and hence instead of yielding up a single sum at the end, it yields up multiple sums. The number of results is nondeterministic, as is the point where the breaks occur.

fn fold_with<F, T>(self, init: T, fold_op: F) -> FoldWith<Self, T, F>

where F: Fn(T, Self::Item) -> T + Sync + Send, T: Send + Clone,

Applies fold_op to the given init value with each item of this iterator, finally producing the value for further use.

fn try_fold<T, R, ID, F>( self, identity: ID, fold_op: F, ) -> TryFold<Self, R, ID, F>

where F: Fn(T, Self::Item) -> R + Sync + Send, ID: Fn() -> T + Sync + Send, R: Try<Output = T> + Send,

Performs a fallible parallel fold.

fn try_fold_with<F, T, R>(self, init: T, fold_op: F) -> TryFoldWith<Self, R, F>

where F: Fn(T, Self::Item) -> R + Sync + Send, R: Try<Output = T> + Send, T: Clone + Send,

Performs a fallible parallel fold with a cloneable init value.

fn sum<S>(self) -> S

where S: Send + Sum<Self::Item> + Sum,

Sums up the items in the iterator.

fn product<P>(self) -> P

where P: Send + Product<Self::Item> + Product,

Multiplies all the items in the iterator.

fn min_by<F>(self, f: F) -> Option<Self::Item>

where F: Sync + Send + Fn(&Self::Item, &Self::Item) -> Ordering,

Computes the minimum of all the items in the iterator with respect to the given comparison function. If the iterator is empty, None is returned; otherwise, Some(min) is returned.

fn min_by_key<K, F>(self, f: F) -> Option<Self::Item>

where K: Ord + Send, F: Sync + Send + Fn(&Self::Item) -> K,

Computes the item that yields the minimum value for the given function. If the iterator is empty, None is returned; otherwise, Some(item) is returned.

fn max_by<F>(self, f: F) -> Option<Self::Item>

where F: Sync + Send + Fn(&Self::Item, &Self::Item) -> Ordering,

Computes the maximum of all the items in the iterator with respect to the given comparison function. If the iterator is empty, None is returned; otherwise, Some(max) is returned.

fn max_by_key<K, F>(self, f: F) -> Option<Self::Item>

where K: Ord + Send, F: Sync + Send + Fn(&Self::Item) -> K,

Computes the item that yields the maximum value for the given function. If the iterator is empty, None is returned; otherwise, Some(item) is returned.

fn chain<C>(self, chain: C) -> Chain<Self, <C as IntoParallelIterator>::Iter>

where C: IntoParallelIterator<Item = Self::Item>,

Takes two iterators and creates a new iterator over both.

fn find_any<P>(self, predicate: P) -> Option<Self::Item>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Searches for some item in the parallel iterator that matches the given predicate and returns it. This operation is similar to find on sequential iterators but the item returned may not be the first one in the parallel sequence which matches, since we search the entire sequence in parallel.

fn find_first<P>(self, predicate: P) -> Option<Self::Item>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Searches for the sequentially first item in the parallel iterator that matches the given predicate and returns it.

fn find_last<P>(self, predicate: P) -> Option<Self::Item>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Searches for the sequentially last item in the parallel iterator that matches the given predicate and returns it.

fn find_map_any<P, R>(self, predicate: P) -> Option<R>

where P: Fn(Self::Item) -> Option<R> + Sync + Send, R: Send,

Applies the given predicate to the items in the parallel iterator and returns any non-None result of the map operation.

fn find_map_first<P, R>(self, predicate: P) -> Option<R>

where P: Fn(Self::Item) -> Option<R> + Sync + Send, R: Send,

Applies the given predicate to the items in the parallel iterator and returns the sequentially first non-None result of the map operation.

fn find_map_last<P, R>(self, predicate: P) -> Option<R>

where P: Fn(Self::Item) -> Option<R> + Sync + Send, R: Send,

Applies the given predicate to the items in the parallel iterator and returns the sequentially last non-None result of the map operation.

fn any<P>(self, predicate: P) -> bool

where P: Fn(Self::Item) -> bool + Sync + Send,

Searches for some item in the parallel iterator that matches the given predicate, and if so returns true. Once a match is found, we’ll attempt to stop process the rest of the items. Proving that there’s no match, returning false, does require visiting every item.

fn all<P>(self, predicate: P) -> bool

where P: Fn(Self::Item) -> bool + Sync + Send,

Tests that every item in the parallel iterator matches the given predicate, and if so returns true. If a counter-example is found, we’ll attempt to stop processing more items, then return false.

fn while_some<T>(self) -> WhileSome<Self>

where Self: ParallelIterator<Item = Option<T>>, T: Send,

Creates an iterator over the Some items of this iterator, halting as soon as any None is found.

fn panic_fuse(self) -> PanicFuse<Self>

Wraps an iterator with a fuse in case of panics, to halt all threads as soon as possible.

fn collect<C>(self) -> C

where C: FromParallelIterator<Self::Item>,

Creates a fresh collection containing all the elements produced by this parallel iterator.

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)

where Self: ParallelIterator<Item = (A, B)>, FromA: Default + Send + ParallelExtend<A>, FromB: Default + Send + ParallelExtend<B>, A: Send, B: Send,

Unzips the items of a parallel iterator into a pair of arbitrary ParallelExtend containers.

fn partition<A, B, P>(self, predicate: P) -> (A, B)

where A: Default + Send + ParallelExtend<Self::Item>, B: Default + Send + ParallelExtend<Self::Item>, P: Fn(&Self::Item) -> bool + Sync + Send,

Partitions the items of a parallel iterator into a pair of arbitrary ParallelExtend containers. Items for which the predicate returns true go into the first container, and the rest go into the second.

fn partition_map<A, B, P, L, R>(self, predicate: P) -> (A, B)

where A: Default + Send + ParallelExtend<L>, B: Default + Send + ParallelExtend<R>, P: Fn(Self::Item) -> Either<L, R> + Sync + Send, L: Send, R: Send,

Partitions and maps the items of a parallel iterator into a pair of arbitrary ParallelExtend containers. Either::Left items go into the first container, and Either::Right items go into the second.

fn take_any(self, n: usize) -> TakeAny<Self>

Creates an iterator that yields n elements from anywhere in the original iterator.

fn skip_any(self, n: usize) -> SkipAny<Self>

Creates an iterator that skips n elements from anywhere in the original iterator.

fn take_any_while<P>(self, predicate: P) -> TakeAnyWhile<Self, P>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Creates an iterator that takes elements from anywhere in the original iterator until the given predicate returns false.

fn skip_any_while<P>(self, predicate: P) -> SkipAnyWhile<Self, P>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Creates an iterator that skips elements from anywhere in the original iterator until the given predicate returns false.

fn collect_vec_list(self) -> LinkedList<Vec<Self::Item>>

Collects this iterator into a linked list of vectors.

impl<E: Element> ParallelIterator for VecStore<E>

type Item = E

The type of item that this parallel iterator produces. For example, if you use the for_each method, this is the type of item that your closure will be invoked with.

fn drive_unindexed<C>(self, consumer: C) -> C::Result

where C: UnindexedConsumer<Self::Item>,

Internal method used to define the behavior of this parallel iterator. You should not need to call this directly.

fn opt_len(&self) -> Option<usize>

Internal method used to define the behavior of this parallel iterator. You should not need to call this directly.

fn for_each<OP>(self, op: OP)

where OP: Fn(Self::Item) + Sync + Send,

Executes OP on each item produced by the iterator, in parallel.

fn for_each_with<OP, T>(self, init: T, op: OP)

where OP: Fn(&mut T, Self::Item) + Sync + Send, T: Send + Clone,

Executes OP on the given init value with each item produced by the iterator, in parallel.

fn for_each_init<OP, INIT, T>(self, init: INIT, op: OP)

where OP: Fn(&mut T, Self::Item) + Sync + Send, INIT: Fn() -> T + Sync + Send,

Executes OP on a value returned by init with each item produced by the iterator, in parallel.

fn try_for_each<OP, R>(self, op: OP) -> R

where OP: Fn(Self::Item) -> R + Sync + Send, R: Try<Output = ()> + Send,

Executes a fallible OP on each item produced by the iterator, in parallel.

fn try_for_each_with<OP, T, R>(self, init: T, op: OP) -> R

where OP: Fn(&mut T, Self::Item) -> R + Sync + Send, T: Send + Clone, R: Try<Output = ()> + Send,

Executes a fallible OP on the given init value with each item produced by the iterator, in parallel.

fn try_for_each_init<OP, INIT, T, R>(self, init: INIT, op: OP) -> R

where OP: Fn(&mut T, Self::Item) -> R + Sync + Send, INIT: Fn() -> T + Sync + Send, R: Try<Output = ()> + Send,

Executes a fallible OP on a value returned by init with each item produced by the iterator, in parallel.

fn count(self) -> usize

Counts the number of items in this parallel iterator.

fn map<F, R>(self, map_op: F) -> Map<Self, F>

where F: Fn(Self::Item) -> R + Sync + Send, R: Send,

Applies map_op to each item of this iterator, producing a new iterator with the results.

fn map_with<F, T, R>(self, init: T, map_op: F) -> MapWith<Self, T, F>

where F: Fn(&mut T, Self::Item) -> R + Sync + Send, T: Send + Clone, R: Send,

Applies map_op to the given init value with each item of this iterator, producing a new iterator with the results.

fn map_init<F, INIT, T, R>( self, init: INIT, map_op: F, ) -> MapInit<Self, INIT, F>

where F: Fn(&mut T, Self::Item) -> R + Sync + Send, INIT: Fn() -> T + Sync + Send, R: Send,

Applies map_op to a value returned by init with each item of this iterator, producing a new iterator with the results.

fn cloned<'a, T>(self) -> Cloned<Self>

where T: 'a + Clone + Send, Self: ParallelIterator<Item = &'a T>,

Creates an iterator which clones all of its elements. This may be useful when you have an iterator over &T, but you need T, and that type implements Clone. See also copied().

fn copied<'a, T>(self) -> Copied<Self>

where T: 'a + Copy + Send, Self: ParallelIterator<Item = &'a T>,

Creates an iterator which copies all of its elements. This may be useful when you have an iterator over &T, but you need T, and that type implements Copy. See also cloned().

fn inspect<OP>(self, inspect_op: OP) -> Inspect<Self, OP>

where OP: Fn(&Self::Item) + Sync + Send,

Applies inspect_op to a reference to each item of this iterator, producing a new iterator passing through the original items. This is often useful for debugging to see what’s happening in iterator stages.

fn update<F>(self, update_op: F) -> Update<Self, F>

where F: Fn(&mut Self::Item) + Sync + Send,

Mutates each item of this iterator before yielding it.

fn filter<P>(self, filter_op: P) -> Filter<Self, P>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Applies filter_op to each item of this iterator, producing a new iterator with only the items that gave true results.

fn filter_map<P, R>(self, filter_op: P) -> FilterMap<Self, P>

where P: Fn(Self::Item) -> Option<R> + Sync + Send, R: Send,

Applies filter_op to each item of this iterator to get an Option, producing a new iterator with only the items from Some results.

fn flat_map<F, PI>(self, map_op: F) -> FlatMap<Self, F>

where F: Fn(Self::Item) -> PI + Sync + Send, PI: IntoParallelIterator,

Applies map_op to each item of this iterator to get nested parallel iterators, producing a new parallel iterator that flattens these back into one.

fn flat_map_iter<F, SI>(self, map_op: F) -> FlatMapIter<Self, F>

where F: Fn(Self::Item) -> SI + Sync + Send, SI: IntoIterator, <SI as IntoIterator>::Item: Send,

Applies map_op to each item of this iterator to get nested serial iterators, producing a new parallel iterator that flattens these back into one.

fn reduce<OP, ID>(self, identity: ID, op: OP) -> Self::Item

where OP: Fn(Self::Item, Self::Item) -> Self::Item + Sync + Send, ID: Fn() -> Self::Item + Sync + Send,

Reduces the items in the iterator into one item using op. The argument identity should be a closure that can produce “identity” value which may be inserted into the sequence as needed to create opportunities for parallel execution. So, for example, if you are doing a summation, then identity() ought to produce something that represents the zero for your type (but consider just calling sum() in that case).

fn reduce_with<OP>(self, op: OP) -> Option<Self::Item>

where OP: Fn(Self::Item, Self::Item) -> Self::Item + Sync + Send,

Reduces the items in the iterator into one item using op. If the iterator is empty, None is returned; otherwise, Some is returned.

fn fold<T, ID, F>(self, identity: ID, fold_op: F) -> Fold<Self, ID, F>

where F: Fn(T, Self::Item) -> T + Sync + Send, ID: Fn() -> T + Sync + Send, T: Send,

Parallel fold is similar to sequential fold except that the sequence of items may be subdivided before it is folded. Consider a list of numbers like 22 3 77 89 46. If you used sequential fold to add them (fold(0, |a,b| a+b), you would wind up first adding 0 + 22, then 22 + 3, then 25 + 77, and so forth. The parallel fold works similarly except that it first breaks up your list into sublists, and hence instead of yielding up a single sum at the end, it yields up multiple sums. The number of results is nondeterministic, as is the point where the breaks occur.

fn fold_with<F, T>(self, init: T, fold_op: F) -> FoldWith<Self, T, F>

where F: Fn(T, Self::Item) -> T + Sync + Send, T: Send + Clone,

Applies fold_op to the given init value with each item of this iterator, finally producing the value for further use.

fn try_fold<T, R, ID, F>( self, identity: ID, fold_op: F, ) -> TryFold<Self, R, ID, F>

where F: Fn(T, Self::Item) -> R + Sync + Send, ID: Fn() -> T + Sync + Send, R: Try<Output = T> + Send,

Performs a fallible parallel fold.

fn try_fold_with<F, T, R>(self, init: T, fold_op: F) -> TryFoldWith<Self, R, F>

where F: Fn(T, Self::Item) -> R + Sync + Send, R: Try<Output = T> + Send, T: Clone + Send,

Performs a fallible parallel fold with a cloneable init value.

fn sum<S>(self) -> S

where S: Send + Sum<Self::Item> + Sum,

Sums up the items in the iterator.

fn product<P>(self) -> P

where P: Send + Product<Self::Item> + Product,

Multiplies all the items in the iterator.

fn min_by<F>(self, f: F) -> Option<Self::Item>

where F: Sync + Send + Fn(&Self::Item, &Self::Item) -> Ordering,

Computes the minimum of all the items in the iterator with respect to the given comparison function. If the iterator is empty, None is returned; otherwise, Some(min) is returned.

fn min_by_key<K, F>(self, f: F) -> Option<Self::Item>

where K: Ord + Send, F: Sync + Send + Fn(&Self::Item) -> K,

Computes the item that yields the minimum value for the given function. If the iterator is empty, None is returned; otherwise, Some(item) is returned.

fn max_by<F>(self, f: F) -> Option<Self::Item>

where F: Sync + Send + Fn(&Self::Item, &Self::Item) -> Ordering,

Computes the maximum of all the items in the iterator with respect to the given comparison function. If the iterator is empty, None is returned; otherwise, Some(max) is returned.

fn max_by_key<K, F>(self, f: F) -> Option<Self::Item>

where K: Ord + Send, F: Sync + Send + Fn(&Self::Item) -> K,

Computes the item that yields the maximum value for the given function. If the iterator is empty, None is returned; otherwise, Some(item) is returned.

fn chain<C>(self, chain: C) -> Chain<Self, <C as IntoParallelIterator>::Iter>

where C: IntoParallelIterator<Item = Self::Item>,

Takes two iterators and creates a new iterator over both.

fn find_any<P>(self, predicate: P) -> Option<Self::Item>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Searches for some item in the parallel iterator that matches the given predicate and returns it. This operation is similar to find on sequential iterators but the item returned may not be the first one in the parallel sequence which matches, since we search the entire sequence in parallel.

fn find_first<P>(self, predicate: P) -> Option<Self::Item>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Searches for the sequentially first item in the parallel iterator that matches the given predicate and returns it.

fn find_last<P>(self, predicate: P) -> Option<Self::Item>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Searches for the sequentially last item in the parallel iterator that matches the given predicate and returns it.

fn find_map_any<P, R>(self, predicate: P) -> Option<R>

where P: Fn(Self::Item) -> Option<R> + Sync + Send, R: Send,

Applies the given predicate to the items in the parallel iterator and returns any non-None result of the map operation.

fn find_map_first<P, R>(self, predicate: P) -> Option<R>

where P: Fn(Self::Item) -> Option<R> + Sync + Send, R: Send,

Applies the given predicate to the items in the parallel iterator and returns the sequentially first non-None result of the map operation.

fn find_map_last<P, R>(self, predicate: P) -> Option<R>

where P: Fn(Self::Item) -> Option<R> + Sync + Send, R: Send,

Applies the given predicate to the items in the parallel iterator and returns the sequentially last non-None result of the map operation.

fn any<P>(self, predicate: P) -> bool

where P: Fn(Self::Item) -> bool + Sync + Send,

Searches for some item in the parallel iterator that matches the given predicate, and if so returns true. Once a match is found, we’ll attempt to stop process the rest of the items. Proving that there’s no match, returning false, does require visiting every item.

fn all<P>(self, predicate: P) -> bool

where P: Fn(Self::Item) -> bool + Sync + Send,

Tests that every item in the parallel iterator matches the given predicate, and if so returns true. If a counter-example is found, we’ll attempt to stop processing more items, then return false.

fn while_some<T>(self) -> WhileSome<Self>

where Self: ParallelIterator<Item = Option<T>>, T: Send,

Creates an iterator over the Some items of this iterator, halting as soon as any None is found.

fn panic_fuse(self) -> PanicFuse<Self>

Wraps an iterator with a fuse in case of panics, to halt all threads as soon as possible.

fn collect<C>(self) -> C

where C: FromParallelIterator<Self::Item>,

Creates a fresh collection containing all the elements produced by this parallel iterator.

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB)

where Self: ParallelIterator<Item = (A, B)>, FromA: Default + Send + ParallelExtend<A>, FromB: Default + Send + ParallelExtend<B>, A: Send, B: Send,

Unzips the items of a parallel iterator into a pair of arbitrary ParallelExtend containers.

fn partition<A, B, P>(self, predicate: P) -> (A, B)

where A: Default + Send + ParallelExtend<Self::Item>, B: Default + Send + ParallelExtend<Self::Item>, P: Fn(&Self::Item) -> bool + Sync + Send,

Partitions the items of a parallel iterator into a pair of arbitrary ParallelExtend containers. Items for which the predicate returns true go into the first container, and the rest go into the second.

fn partition_map<A, B, P, L, R>(self, predicate: P) -> (A, B)

where A: Default + Send + ParallelExtend<L>, B: Default + Send + ParallelExtend<R>, P: Fn(Self::Item) -> Either<L, R> + Sync + Send, L: Send, R: Send,

Partitions and maps the items of a parallel iterator into a pair of arbitrary ParallelExtend containers. Either::Left items go into the first container, and Either::Right items go into the second.

fn take_any(self, n: usize) -> TakeAny<Self>

Creates an iterator that yields n elements from anywhere in the original iterator.

fn skip_any(self, n: usize) -> SkipAny<Self>

Creates an iterator that skips n elements from anywhere in the original iterator.

fn take_any_while<P>(self, predicate: P) -> TakeAnyWhile<Self, P>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Creates an iterator that takes elements from anywhere in the original iterator until the given predicate returns false.

fn skip_any_while<P>(self, predicate: P) -> SkipAnyWhile<Self, P>

where P: Fn(&Self::Item) -> bool + Sync + Send,

Creates an iterator that skips elements from anywhere in the original iterator until the given predicate returns false.

fn collect_vec_list(self) -> LinkedList<Vec<Self::Item>>

Collects this iterator into a linked list of vectors.

impl<E: Element> Store<E> for VecStore<E>

fn new_with_config( size: usize, _branches: usize, _config: StoreConfig, ) -> Result<Self>

Creates a new store which can store up to size elements.

fn new(size: usize) -> Result<Self>

fn write_at(&mut self, el: E, index: usize) -> Result<()>

fn copy_from_slice(&mut self, buf: &[u8], start: usize) -> Result<()>

fn new_from_slice_with_config( size: usize, _branches: usize, data: &[u8], _config: StoreConfig, ) -> Result<Self>

fn new_from_slice(size: usize, data: &[u8]) -> Result<Self>

fn new_from_disk( _size: usize, _branches: usize, _config: &StoreConfig, ) -> Result<Self>

This constructor is used for instantiating stores ONLY from existing (potentially read-only) files

fn read_at(&self, index: usize) -> Result<E>

fn read_into(&self, index: usize, buf: &mut [u8]) -> Result<()>

fn read_range_into( &self, _start: usize, _end: usize, _buf: &mut [u8], ) -> Result<()>

fn read_range(&self, r: Range<usize>) -> Result<Vec<E>>

fn len(&self) -> usize

fn loaded_from_disk(&self) -> bool

fn compact( &mut self, _branches: usize, _config: StoreConfig, _store_version: u32, ) -> Result<bool>

fn delete(_config: StoreConfig) -> Result<()>

fn is_empty(&self) -> bool

fn push(&mut self, el: E) -> Result<()>

fn reinit(&mut self) -> Result<()>

fn last(&self) -> Result<E>

fn sync(&self) -> Result<()>

fn build_small_tree<A: Algorithm<E>, U: Unsigned>( &mut self, leafs: usize, row_count: usize, ) -> Result<E>

fn process_layer<A: Algorithm<E>, U: Unsigned>( &mut self, width: usize, level: usize, read_start: usize, write_start: usize, ) -> Result<()>

fn build<A: Algorithm<E>, U: Unsigned>( &mut self, leafs: usize, row_count: usize, _config: Option<StoreConfig>, ) -> Result<E>