Struct sp_application_crypto::bandersnatch::AppSignature

source ·
pub struct AppSignature(/* private fields */);
Expand description

A generic AppPublic wrapper type over $public crypto; this has no specific App.

Implementations§

source§

impl Signature

source

pub fn into_inner(self) -> Signature

Convert into wrapped generic signature type.

Methods from Deref<Target = [u8]>§

1.0.0 · source

pub fn len(&self) -> usize

Returns the number of elements in the slice.

§Examples
let a = [1, 2, 3];
assert_eq!(a.len(), 3);
1.0.0 · source

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());
1.0.0 · source

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());
1.5.0 · source

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]);
}
1.5.0 · source

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]);
}
1.0.0 · source

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());
1.77.0 · source

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>());
1.77.0 · source

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>());
1.77.0 · source

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>());
1.77.0 · source

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>());
1.0.0 · source

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));
1.0.0 · source

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);
}
1.0.0 · source

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));
    }
}
1.48.0 · source

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));
1.0.0 · source

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);
1.0.0 · source

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']);
1.0.0 · source

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());
1.31.0 · source

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']);
source

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
source

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']]);
source

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']]);
source

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']);
source

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());
1.31.0 · source

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());
1.31.0 · source

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']);
1.77.0 · source

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);
1.0.0 · source

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, []);
}
1.79.0 · source

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, []);
}
1.80.0 · source

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));
1.0.0 · source

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());
1.51.0 · source

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());
1.27.0 · source

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);
1.0.0 · source

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:?}");
}
1.0.0 · source

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:?}");
}
source

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);
source

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);
1.0.0 · source

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"));
1.0.0 · source

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(&[]));
1.0.0 · source

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(&[]));
1.51.0 · source

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()));
1.51.0 · source

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);

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]);
1.0.0 · source

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, });
1.10.0 · source

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, });
1.30.0 · source

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);
}
source

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

🔬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);
source

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());
source

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));
source

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()));
1.52.0 · source

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]);
1.79.0 · source

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);
}
1.23.0 · source

pub fn is_ascii(&self) -> bool

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

source

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.

source

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.

1.23.0 · source

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.

1.60.0 · source

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");
1.80.0 · source

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"");
1.80.0 · source

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"");
1.80.0 · source

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"");
1.80.0 · source

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());
source

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.

source

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.

1.23.0 · source

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.

1.23.0 · source

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.

1.0.0 · source

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.
source

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.
1.40.0 · source

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);
1.0.0 · source

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]);
1.3.0 · source

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]);
1.0.0 · source

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]);

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impl AppCrypto for Signature

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type Public = Public

The corresponding public key type in this application scheme.
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type Pair = Pair

The corresponding key pair type in this application scheme.
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type Signature = Signature

The corresponding signature type in this application scheme.
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const ID: KeyTypeId = sp_core::testing::BANDERSNATCH

Identifier for application-specific key type.
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const CRYPTO_ID: CryptoTypeId = super::CRYPTO_ID

Identifier of the crypto type of this application-specific key type.
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impl AppSignature for Signature

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type Generic = CryptoBytes<sp_core::::bandersnatch::Signature::{constant#0}, (SignatureTag, BandersnatchTag)>

The wrapped type which is just a plain instance of Signature.
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impl AsMut<[u8]> for Signature

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fn as_mut(&mut self) -> &mut [u8]

Converts this type into a mutable reference of the (usually inferred) input type.
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impl AsMut<CryptoBytes<sp_core::::bandersnatch::Signature::{constant#0}, (SignatureTag, BandersnatchTag)>> for Signature

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fn as_mut(&mut self) -> &mut Signature

Converts this type into a mutable reference of the (usually inferred) input type.
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impl AsRef<[u8]> for Signature

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fn as_ref(&self) -> &[u8]

Converts this type into a shared reference of the (usually inferred) input type.
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impl AsRef<CryptoBytes<sp_core::::bandersnatch::Signature::{constant#0}, (SignatureTag, BandersnatchTag)>> for Signature

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fn as_ref(&self) -> &Signature

Converts this type into a shared reference of the (usually inferred) input type.
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impl ByteArray for Signature

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const LEN: usize = 65usize

The “length” of the values of this type, which is always the same.
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fn from_slice(data: &[u8]) -> Result<Self, ()>

A new instance from the given slice that should be Self::LEN bytes long.
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fn to_raw_vec(&self) -> Vec<u8>

Return a Vec<u8> filled with raw data.
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fn as_slice(&self) -> &[u8]

Return a slice filled with raw data.
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impl Clone for Signature

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fn clone(&self) -> Signature

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl CryptoType for Signature

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type Pair = Pair

The pair key type of this crypto.
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impl Debug for Signature

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

Formats the value using the given formatter. Read more
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impl Decode for Signature

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fn decode<__CodecInputEdqy: Input>( __codec_input_edqy: &mut __CodecInputEdqy, ) -> Result<Self, Error>

Attempt to deserialise the value from input.
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fn decode_into<I>( input: &mut I, dst: &mut MaybeUninit<Self>, ) -> Result<DecodeFinished, Error>
where I: Input,

Attempt to deserialize the value from input into a pre-allocated piece of memory. Read more
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fn skip<I>(input: &mut I) -> Result<(), Error>
where I: Input,

Attempt to skip the encoded value from input. Read more
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fn encoded_fixed_size() -> Option<usize>

Returns the fixed encoded size of the type. Read more
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impl Deref for Signature

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type Target = [u8]

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

Dereferences the value.
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impl Encode for Signature

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fn size_hint(&self) -> usize

If possible give a hint of expected size of the encoding. Read more
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fn encode_to<__CodecOutputEdqy: Output + ?Sized>( &self, __codec_dest_edqy: &mut __CodecOutputEdqy, )

Convert self to a slice and append it to the destination.
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fn encode(&self) -> Vec<u8>

Convert self to an owned vector.
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fn using_encoded<__CodecOutputReturn, __CodecUsingEncodedCallback: FnOnce(&[u8]) -> __CodecOutputReturn>( &self, f: __CodecUsingEncodedCallback, ) -> __CodecOutputReturn

Convert self to a slice and then invoke the given closure with it.
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fn encoded_size(&self) -> usize

Calculates the encoded size. Read more
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impl From<CryptoBytes<sp_core::::bandersnatch::Signature::{constant#0}, (SignatureTag, BandersnatchTag)>> for Signature

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fn from(inner: Signature) -> Self

Converts to this type from the input type.
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impl From<Signature> for Signature

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fn from(outer: Signature) -> Self

Converts to this type from the input type.
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impl Hash for Signature

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fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher. Read more
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fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl PartialEq for Signature

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fn eq(&self, other: &Signature) -> bool

This method tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl<'a> TryFrom<&'a [u8]> for Signature

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type Error = ()

The type returned in the event of a conversion error.
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fn try_from(data: &'a [u8]) -> Result<Self, Self::Error>

Performs the conversion.
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impl TryFrom<Vec<u8>> for Signature

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type Error = ()

The type returned in the event of a conversion error.
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fn try_from(data: Vec<u8>) -> Result<Self, Self::Error>

Performs the conversion.
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impl TypeInfo for Signature

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type Identity = Signature

The type identifying for which type info is provided. Read more
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fn type_info() -> Type

Returns the static type identifier for Self.
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impl Wraps for Signature

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type Inner = CryptoBytes<sp_core::::bandersnatch::Signature::{constant#0}, (SignatureTag, BandersnatchTag)>

The inner type it is wrapping.
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fn as_inner_ref(&self) -> &Self::Inner

Get a reference to the inner type that is wrapped.
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impl EncodeLike for Signature

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impl Eq for Signature

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impl Signature for Signature

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impl StructuralPartialEq for Signature

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

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<A, T> AsBits<T> for A
where A: AsRef<[T]>, T: BitStore,

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fn as_bits<O>(&self) -> &BitSlice<T, O>
where O: BitOrder,

Views self as an immutable bit-slice region with the O ordering.
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fn try_as_bits<O>(&self) -> Result<&BitSlice<T, O>, BitSpanError<T>>
where O: BitOrder,

Attempts to view self as an immutable bit-slice region with the O ordering. Read more
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impl<T, U> AsByteSlice<T> for U
where T: ToByteSlice, U: AsRef<[T]> + ?Sized,

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fn as_byte_slice(&self) -> &[u8]

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impl<A, T> AsMutBits<T> for A
where A: AsMut<[T]>, T: BitStore,

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fn as_mut_bits<O>(&mut self) -> &mut BitSlice<T, O>
where O: BitOrder,

Views self as a mutable bit-slice region with the O ordering.
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fn try_as_mut_bits<O>(&mut self) -> Result<&mut BitSlice<T, O>, BitSpanError<T>>
where O: BitOrder,

Attempts to view self as a mutable bit-slice region with the O ordering. Read more
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impl<T, U> AsMutByteSlice<T> for U
where T: ToMutByteSlice, U: AsMut<[T]> + ?Sized,

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fn as_mut_byte_slice(&mut self) -> &mut [u8]

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impl<U> AsMutSliceOf for U
where U: AsMut<[u8]> + ?Sized,

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fn as_mut_slice_of<T>(&mut self) -> Result<&mut [T], Error>
where T: FromByteSlice,

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impl<U> AsSliceOf for U
where U: AsRef<[u8]> + ?Sized,

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fn as_slice_of<T>(&self) -> Result<&[T], Error>
where T: FromByteSlice,

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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

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

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

Mutably borrows from an owned value. Read more
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impl<T> CallHasher for T
where T: Hash + ?Sized,

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fn get_hash<H, B>(value: &H, build_hasher: &B) -> u64
where H: Hash + ?Sized, B: BuildHasher,

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impl<T> CloneToUninit for T
where T: Clone,

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default unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
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impl<T> Conv for T

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fn conv<T>(self) -> T
where Self: Into<T>,

Converts self into T using Into<T>. Read more
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impl<T> DecodeAll for T
where T: Decode,

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fn decode_all(input: &mut &[u8]) -> Result<T, Error>

Decode Self and consume all of the given input data. Read more
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impl<T> DecodeLimit for T
where T: Decode,

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fn decode_all_with_depth_limit( limit: u32, input: &mut &[u8], ) -> Result<T, Error>

Decode Self and consume all of the given input data. Read more
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fn decode_with_depth_limit<I>(limit: u32, input: &mut I) -> Result<T, Error>
where I: Input,

Decode Self with the given maximum recursion depth and advance input by the number of bytes consumed. Read more
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fn __clone_box(&self, _: Private) -> *mut ()

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fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
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impl<Q, K> Equivalent<K> for Q
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fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more
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impl<Q, K> Equivalent<K> for Q
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fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more
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fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
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fn fmt_binary(self) -> FmtBinary<Self>
where Self: Binary,

Causes self to use its Binary implementation when Debug-formatted.
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fn fmt_display(self) -> FmtDisplay<Self>
where Self: Display,

Causes self to use its Display implementation when Debug-formatted.
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fn fmt_lower_exp(self) -> FmtLowerExp<Self>
where Self: LowerExp,

Causes self to use its LowerExp implementation when Debug-formatted.
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fn fmt_lower_hex(self) -> FmtLowerHex<Self>
where Self: LowerHex,

Causes self to use its LowerHex implementation when Debug-formatted.
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where Self: Octal,

Causes self to use its Octal implementation when Debug-formatted.
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where Self: Pointer,

Causes self to use its Pointer implementation when Debug-formatted.
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where Self: UpperExp,

Causes self to use its UpperExp implementation when Debug-formatted.
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where Self: UpperHex,

Causes self to use its UpperHex implementation when Debug-formatted.
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where &'a Self: for<'a> IntoIterator,

Formats each item in a sequence. Read more
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Instruments this type with the provided [Span], returning an Instrumented wrapper. Read more
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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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Return an encoding of Self prepended by given slice.
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Pipes by value. This is generally the method you want to use. Read more
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where R: 'a,

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Encode the hex strict representing self into the result. Lower case letters are used (e.g. f9b4ca)
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