Struct sgx_types::types::Sha384Hash
source · [−]Fields
hash: [u8; 48]
Implementations
sourceimpl Sha384Hash
impl Sha384Hash
Methods from Deref<Target = [u8]>
1.0.0 · sourcepub fn first(&self) -> Option<&T>
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());
1.0.0 · sourcepub fn first_mut(&mut self) -> Option<&mut T>
pub fn first_mut(&mut self) -> Option<&mut T>
Returns a mutable pointer to the first element of the slice, or None
if it is empty.
Examples
let x = &mut [0, 1, 2];
if let Some(first) = x.first_mut() {
*first = 5;
}
assert_eq!(x, &[5, 1, 2]);
1.5.0 · sourcepub fn split_first(&self) -> Option<(&T, &[T])>
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 · sourcepub fn split_first_mut(&mut self) -> Option<(&mut T, &mut [T])>
pub fn split_first_mut(&mut self) -> Option<(&mut T, &mut [T])>
Returns the first and all the rest of the elements of the slice, or None
if it is empty.
Examples
let x = &mut [0, 1, 2];
if let Some((first, elements)) = x.split_first_mut() {
*first = 3;
elements[0] = 4;
elements[1] = 5;
}
assert_eq!(x, &[3, 4, 5]);
1.5.0 · sourcepub fn split_last(&self) -> Option<(&T, &[T])>
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]);
}
1.5.0 · sourcepub fn split_last_mut(&mut self) -> Option<(&mut T, &mut [T])>
pub fn split_last_mut(&mut self) -> Option<(&mut T, &mut [T])>
Returns the last and all the rest of the elements of the slice, or None
if it is empty.
Examples
let x = &mut [0, 1, 2];
if let Some((last, elements)) = x.split_last_mut() {
*last = 3;
elements[0] = 4;
elements[1] = 5;
}
assert_eq!(x, &[4, 5, 3]);
1.0.0 · sourcepub fn last(&self) -> Option<&T>
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());
1.0.0 · sourcepub fn last_mut(&mut self) -> Option<&mut T>
pub fn last_mut(&mut self) -> Option<&mut T>
Returns a mutable pointer to the last item in the slice.
Examples
let x = &mut [0, 1, 2];
if let Some(last) = x.last_mut() {
*last = 10;
}
assert_eq!(x, &[0, 1, 10]);
1.0.0 · sourcepub fn get<I>(&self, index: I) -> Option<&<I as SliceIndex<[T]>>::Output>where
I: SliceIndex<[T]>,
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 · sourcepub fn get_mut<I>(
&mut self,
index: I
) -> Option<&mut <I as SliceIndex<[T]>>::Output>where
I: SliceIndex<[T]>,
pub fn get_mut<I>(
&mut self,
index: I
) -> Option<&mut <I as SliceIndex<[T]>>::Output>where
I: SliceIndex<[T]>,
1.0.0 · sourcepub unsafe fn get_unchecked<I>(
&self,
index: I
) -> &<I as SliceIndex<[T]>>::Outputwhere
I: SliceIndex<[T]>,
pub unsafe fn get_unchecked<I>(
&self,
index: I
) -> &<I as SliceIndex<[T]>>::Outputwhere
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.
Examples
let x = &[1, 2, 4];
unsafe {
assert_eq!(x.get_unchecked(1), &2);
}
1.0.0 · sourcepub unsafe fn get_unchecked_mut<I>(
&mut self,
index: I
) -> &mut <I as SliceIndex<[T]>>::Outputwhere
I: SliceIndex<[T]>,
pub unsafe fn get_unchecked_mut<I>(
&mut self,
index: I
) -> &mut <I as SliceIndex<[T]>>::Outputwhere
I: SliceIndex<[T]>,
Returns a mutable reference to an element or subslice, without doing bounds checking.
For a safe alternative see get_mut
.
Safety
Calling this method with an out-of-bounds index is undefined behavior even if the resulting reference is not used.
Examples
let x = &mut [1, 2, 4];
unsafe {
let elem = x.get_unchecked_mut(1);
*elem = 13;
}
assert_eq!(x, &[1, 13, 4]);
1.0.0 · sourcepub fn as_ptr(&self) -> *const T
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));
}
}
1.0.0 · sourcepub fn as_mut_ptr(&mut self) -> *mut T
pub fn as_mut_ptr(&mut self) -> *mut T
Returns an unsafe mutable 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.
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 = &mut [1, 2, 4];
let x_ptr = x.as_mut_ptr();
unsafe {
for i in 0..x.len() {
*x_ptr.add(i) += 2;
}
}
assert_eq!(x, &[3, 4, 6]);
1.48.0 · sourcepub fn as_ptr_range(&self) -> Range<*const T>
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));
1.48.0 · sourcepub fn as_mut_ptr_range(&mut self) -> Range<*mut T>
pub fn as_mut_ptr_range(&mut self) -> Range<*mut T>
Returns the two unsafe mutable 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_mut_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++.
sourcepub unsafe fn swap_unchecked(&mut self, a: usize, b: usize)
🔬This is a nightly-only experimental API. (slice_swap_unchecked
)
pub unsafe fn swap_unchecked(&mut self, a: usize, b: usize)
slice_swap_unchecked
)Swaps two elements in the slice, without doing bounds checking.
For a safe alternative see swap
.
Arguments
- a - The index of the first element
- b - The index of the second element
Safety
Calling this method with an out-of-bounds index is undefined behavior.
The caller has to ensure that a < self.len()
and b < self.len()
.
Examples
#![feature(slice_swap_unchecked)]
let mut v = ["a", "b", "c", "d"];
// SAFETY: we know that 1 and 3 are both indices of the slice
unsafe { v.swap_unchecked(1, 3) };
assert!(v == ["a", "d", "c", "b"]);
1.0.0 · sourcepub fn reverse(&mut self)
pub fn reverse(&mut self)
Reverses the order of elements in the slice, in place.
Examples
let mut v = [1, 2, 3];
v.reverse();
assert!(v == [3, 2, 1]);
1.0.0 · sourcepub fn iter(&self) -> Iter<'_, T>
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 · sourcepub fn iter_mut(&mut self) -> IterMut<'_, T>
pub fn iter_mut(&mut self) -> IterMut<'_, T>
Returns an iterator that allows modifying each value.
The iterator yields all items from start to end.
Examples
let x = &mut [1, 2, 4];
for elem in x.iter_mut() {
*elem += 2;
}
assert_eq!(x, &[3, 4, 6]);
1.0.0 · sourcepub fn windows(&self, size: usize) -> Windows<'_, T>
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 = ['r', 'u', 's', 't'];
let mut iter = slice.windows(2);
assert_eq!(iter.next().unwrap(), &['r', 'u']);
assert_eq!(iter.next().unwrap(), &['u', 's']);
assert_eq!(iter.next().unwrap(), &['s', 't']);
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());
1.0.0 · sourcepub fn chunks(&self, chunk_size: usize) -> Chunks<'_, T>
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());
1.0.0 · sourcepub fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<'_, T>
pub fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<'_, T>
Returns an iterator over chunk_size
elements of the slice at a time, starting at the
beginning of the slice.
The chunks are mutable 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_mut
for a variant of this iterator that returns chunks of always
exactly chunk_size
elements, and rchunks_mut
for the same iterator but starting at
the end of the slice.
Panics
Panics if chunk_size
is 0.
Examples
let v = &mut [0, 0, 0, 0, 0];
let mut count = 1;
for chunk in v.chunks_mut(2) {
for elem in chunk.iter_mut() {
*elem += count;
}
count += 1;
}
assert_eq!(v, &[1, 1, 2, 2, 3]);
1.31.0 · sourcepub fn chunks_exact(&self, chunk_size: usize) -> ChunksExact<'_, T>
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']);
1.31.0 · sourcepub fn chunks_exact_mut(&mut self, chunk_size: usize) -> ChunksExactMut<'_, T>
pub fn chunks_exact_mut(&mut self, chunk_size: usize) -> ChunksExactMut<'_, T>
Returns an iterator over chunk_size
elements of the slice at a time, starting at the
beginning of the slice.
The chunks are mutable 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 into_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_mut
.
See chunks_mut
for a variant of this iterator that also returns the remainder as a
smaller chunk, and rchunks_exact_mut
for the same iterator but starting at the end of
the slice.
Panics
Panics if chunk_size
is 0.
Examples
let v = &mut [0, 0, 0, 0, 0];
let mut count = 1;
for chunk in v.chunks_exact_mut(2) {
for elem in chunk.iter_mut() {
*elem += count;
}
count += 1;
}
assert_eq!(v, &[1, 1, 2, 2, 0]);
sourcepub unsafe fn as_chunks_unchecked<const N: usize>(&self) -> &[[T; N]]
🔬This is a nightly-only experimental API. (slice_as_chunks
)
pub unsafe fn as_chunks_unchecked<const N: usize>(&self) -> &[[T; N]]
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 (akaself.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
sourcepub fn as_chunks<const N: usize>(&self) -> (&[[T; N]], &[T])
🔬This is a nightly-only experimental API. (slice_as_chunks
)
pub fn as_chunks<const N: usize>(&self) -> (&[[T; N]], &[T])
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']);
sourcepub fn as_rchunks<const N: usize>(&self) -> (&[T], &[[T; N]])
🔬This is a nightly-only experimental API. (slice_as_chunks
)
pub fn as_rchunks<const N: usize>(&self) -> (&[T], &[[T; N]])
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']]);
sourcepub fn array_chunks<const N: usize>(&self) -> ArrayChunks<'_, T, N>
🔬This is a nightly-only experimental API. (array_chunks
)
pub fn array_chunks<const N: usize>(&self) -> ArrayChunks<'_, T, N>
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']);
sourcepub unsafe fn as_chunks_unchecked_mut<const N: usize>(
&mut self
) -> &mut [[T; N]]
🔬This is a nightly-only experimental API. (slice_as_chunks
)
pub unsafe fn as_chunks_unchecked_mut<const N: usize>(
&mut self
) -> &mut [[T; N]]
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 (akaself.len() % N == 0
). N != 0
.
Examples
#![feature(slice_as_chunks)]
let slice: &mut [char] = &mut ['l', 'o', 'r', 'e', 'm', '!'];
let chunks: &mut [[char; 1]] =
// SAFETY: 1-element chunks never have remainder
unsafe { slice.as_chunks_unchecked_mut() };
chunks[0] = ['L'];
assert_eq!(chunks, &[['L'], ['o'], ['r'], ['e'], ['m'], ['!']]);
let chunks: &mut [[char; 3]] =
// SAFETY: The slice length (6) is a multiple of 3
unsafe { slice.as_chunks_unchecked_mut() };
chunks[1] = ['a', 'x', '?'];
assert_eq!(slice, &['L', 'o', 'r', 'a', 'x', '?']);
// These would be unsound:
// let chunks: &[[_; 5]] = slice.as_chunks_unchecked_mut() // The slice length is not a multiple of 5
// let chunks: &[[_; 0]] = slice.as_chunks_unchecked_mut() // Zero-length chunks are never allowed
sourcepub fn as_chunks_mut<const N: usize>(&mut self) -> (&mut [[T; N]], &mut [T])
🔬This is a nightly-only experimental API. (slice_as_chunks
)
pub fn as_chunks_mut<const N: usize>(&mut self) -> (&mut [[T; N]], &mut [T])
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 v = &mut [0, 0, 0, 0, 0];
let mut count = 1;
let (chunks, remainder) = v.as_chunks_mut();
remainder[0] = 9;
for chunk in chunks {
*chunk = [count; 2];
count += 1;
}
assert_eq!(v, &[1, 1, 2, 2, 9]);
sourcepub fn as_rchunks_mut<const N: usize>(&mut self) -> (&mut [T], &mut [[T; N]])
🔬This is a nightly-only experimental API. (slice_as_chunks
)
pub fn as_rchunks_mut<const N: usize>(&mut self) -> (&mut [T], &mut [[T; N]])
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 v = &mut [0, 0, 0, 0, 0];
let mut count = 1;
let (remainder, chunks) = v.as_rchunks_mut();
remainder[0] = 9;
for chunk in chunks {
*chunk = [count; 2];
count += 1;
}
assert_eq!(v, &[9, 1, 1, 2, 2]);
sourcepub fn array_chunks_mut<const N: usize>(&mut self) -> ArrayChunksMut<'_, T, N>
🔬This is a nightly-only experimental API. (array_chunks
)
pub fn array_chunks_mut<const N: usize>(&mut self) -> ArrayChunksMut<'_, T, N>
array_chunks
)Returns an iterator over N
elements of the slice at a time, starting at the
beginning of the slice.
The chunks are mutable 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 into_remainder
function of the iterator.
This method is the const generic equivalent of chunks_exact_mut
.
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 v = &mut [0, 0, 0, 0, 0];
let mut count = 1;
for chunk in v.array_chunks_mut() {
*chunk = [count; 2];
count += 1;
}
assert_eq!(v, &[1, 1, 2, 2, 0]);
sourcepub fn array_windows<const N: usize>(&self) -> ArrayWindows<'_, T, N>
🔬This is a nightly-only experimental API. (array_windows
)
pub fn array_windows<const N: usize>(&self) -> ArrayWindows<'_, T, N>
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 · sourcepub fn rchunks(&self, chunk_size: usize) -> RChunks<'_, T>
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 · sourcepub fn rchunks_mut(&mut self, chunk_size: usize) -> RChunksMut<'_, T>
pub fn rchunks_mut(&mut self, chunk_size: usize) -> RChunksMut<'_, T>
Returns an iterator over chunk_size
elements of the slice at a time, starting at the end
of the slice.
The chunks are mutable 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_mut
for a variant of this iterator that returns chunks of always
exactly chunk_size
elements, and chunks_mut
for the same iterator but starting at the
beginning of the slice.
Panics
Panics if chunk_size
is 0.
Examples
let v = &mut [0, 0, 0, 0, 0];
let mut count = 1;
for chunk in v.rchunks_mut(2) {
for elem in chunk.iter_mut() {
*elem += count;
}
count += 1;
}
assert_eq!(v, &[3, 2, 2, 1, 1]);
1.31.0 · sourcepub fn rchunks_exact(&self, chunk_size: usize) -> RChunksExact<'_, T>
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']);
1.31.0 · sourcepub fn rchunks_exact_mut(&mut self, chunk_size: usize) -> RChunksExactMut<'_, T>
pub fn rchunks_exact_mut(&mut self, chunk_size: usize) -> RChunksExactMut<'_, T>
Returns an iterator over chunk_size
elements of the slice at a time, starting at the end
of the slice.
The chunks are mutable 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 into_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_mut
.
See rchunks_mut
for a variant of this iterator that also returns the remainder as a
smaller chunk, and chunks_exact_mut
for the same iterator but starting at the beginning
of the slice.
Panics
Panics if chunk_size
is 0.
Examples
let v = &mut [0, 0, 0, 0, 0];
let mut count = 1;
for chunk in v.rchunks_exact_mut(2) {
for elem in chunk.iter_mut() {
*elem += count;
}
count += 1;
}
assert_eq!(v, &[0, 2, 2, 1, 1]);
sourcepub fn group_by<F>(&self, pred: F) -> GroupBy<'_, T, F>where
F: FnMut(&T, &T) -> bool,
🔬This is a nightly-only experimental API. (slice_group_by
)
pub fn group_by<F>(&self, pred: F) -> GroupBy<'_, T, F>where
F: FnMut(&T, &T) -> bool,
slice_group_by
)Returns an iterator over the slice producing non-overlapping runs of elements using the predicate to separate them.
The predicate is called on two elements following themselves,
it means the predicate is called on slice[0]
and slice[1]
then on slice[1]
and slice[2]
and so on.
Examples
#![feature(slice_group_by)]
let slice = &[1, 1, 1, 3, 3, 2, 2, 2];
let mut iter = slice.group_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:
#![feature(slice_group_by)]
let slice = &[1, 1, 2, 3, 2, 3, 2, 3, 4];
let mut iter = slice.group_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);
sourcepub fn group_by_mut<F>(&mut self, pred: F) -> GroupByMut<'_, T, F>where
F: FnMut(&T, &T) -> bool,
🔬This is a nightly-only experimental API. (slice_group_by
)
pub fn group_by_mut<F>(&mut self, pred: F) -> GroupByMut<'_, T, F>where
F: FnMut(&T, &T) -> bool,
slice_group_by
)Returns an iterator over the slice producing non-overlapping mutable runs of elements using the predicate to separate them.
The predicate is called on two elements following themselves,
it means the predicate is called on slice[0]
and slice[1]
then on slice[1]
and slice[2]
and so on.
Examples
#![feature(slice_group_by)]
let slice = &mut [1, 1, 1, 3, 3, 2, 2, 2];
let mut iter = slice.group_by_mut(|a, b| a == b);
assert_eq!(iter.next(), Some(&mut [1, 1, 1][..]));
assert_eq!(iter.next(), Some(&mut [3, 3][..]));
assert_eq!(iter.next(), Some(&mut [2, 2, 2][..]));
assert_eq!(iter.next(), None);
This method can be used to extract the sorted subslices:
#![feature(slice_group_by)]
let slice = &mut [1, 1, 2, 3, 2, 3, 2, 3, 4];
let mut iter = slice.group_by_mut(|a, b| a <= b);
assert_eq!(iter.next(), Some(&mut [1, 1, 2, 3][..]));
assert_eq!(iter.next(), Some(&mut [2, 3][..]));
assert_eq!(iter.next(), Some(&mut [2, 3, 4][..]));
assert_eq!(iter.next(), None);
1.0.0 · sourcepub fn split_at(&self, mid: usize) -> (&[T], &[T])
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
.
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, []);
}
1.0.0 · sourcepub fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T])
pub fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T])
Divides one mutable 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
.
Examples
let mut v = [1, 0, 3, 0, 5, 6];
let (left, right) = v.split_at_mut(2);
assert_eq!(left, [1, 0]);
assert_eq!(right, [3, 0, 5, 6]);
left[1] = 2;
right[1] = 4;
assert_eq!(v, [1, 2, 3, 4, 5, 6]);
sourcepub unsafe fn split_at_unchecked(&self, mid: usize) -> (&[T], &[T])
🔬This is a nightly-only experimental API. (slice_split_at_unchecked
)
pub unsafe fn split_at_unchecked(&self, mid: usize) -> (&[T], &[T])
slice_split_at_unchecked
)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
#![feature(slice_split_at_unchecked)]
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, []);
}
sourcepub unsafe fn split_at_mut_unchecked(
&mut self,
mid: usize
) -> (&mut [T], &mut [T])
🔬This is a nightly-only experimental API. (slice_split_at_unchecked
)
pub unsafe fn split_at_mut_unchecked(
&mut self,
mid: usize
) -> (&mut [T], &mut [T])
slice_split_at_unchecked
)Divides one mutable 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_mut
.
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
#![feature(slice_split_at_unchecked)]
let mut v = [1, 0, 3, 0, 5, 6];
// scoped to restrict the lifetime of the borrows
unsafe {
let (left, right) = v.split_at_mut_unchecked(2);
assert_eq!(left, [1, 0]);
assert_eq!(right, [3, 0, 5, 6]);
left[1] = 2;
right[1] = 4;
}
assert_eq!(v, [1, 2, 3, 4, 5, 6]);
sourcepub fn split_array_ref<const N: usize>(&self) -> (&[T; N], &[T])
🔬This is a nightly-only experimental API. (split_array
)
pub fn split_array_ref<const N: usize>(&self) -> (&[T; N], &[T])
split_array
)Divides one slice into an array and a remainder slice at an index.
The array will contain all indices from [0, N)
(excluding
the index N
itself) and the slice will contain all
indices from [N, len)
(excluding the index len
itself).
Panics
Panics if N > len
.
Examples
#![feature(split_array)]
let v = &[1, 2, 3, 4, 5, 6][..];
{
let (left, right) = v.split_array_ref::<0>();
assert_eq!(left, &[]);
assert_eq!(right, [1, 2, 3, 4, 5, 6]);
}
{
let (left, right) = v.split_array_ref::<2>();
assert_eq!(left, &[1, 2]);
assert_eq!(right, [3, 4, 5, 6]);
}
{
let (left, right) = v.split_array_ref::<6>();
assert_eq!(left, &[1, 2, 3, 4, 5, 6]);
assert_eq!(right, []);
}
sourcepub fn split_array_mut<const N: usize>(&mut self) -> (&mut [T; N], &mut [T])
🔬This is a nightly-only experimental API. (split_array
)
pub fn split_array_mut<const N: usize>(&mut self) -> (&mut [T; N], &mut [T])
split_array
)Divides one mutable slice into an array and a remainder slice at an index.
The array will contain all indices from [0, N)
(excluding
the index N
itself) and the slice will contain all
indices from [N, len)
(excluding the index len
itself).
Panics
Panics if N > len
.
Examples
#![feature(split_array)]
let mut v = &mut [1, 0, 3, 0, 5, 6][..];
let (left, right) = v.split_array_mut::<2>();
assert_eq!(left, &mut [1, 0]);
assert_eq!(right, [3, 0, 5, 6]);
left[1] = 2;
right[1] = 4;
assert_eq!(v, [1, 2, 3, 4, 5, 6]);
sourcepub fn rsplit_array_ref<const N: usize>(&self) -> (&[T], &[T; N])
🔬This is a nightly-only experimental API. (split_array
)
pub fn rsplit_array_ref<const N: usize>(&self) -> (&[T], &[T; N])
split_array
)Divides one slice into an array and a remainder slice at an index from the end.
The slice will contain all indices from [0, len - N)
(excluding
the index len - N
itself) and the array will contain all
indices from [len - N, len)
(excluding the index len
itself).
Panics
Panics if N > len
.
Examples
#![feature(split_array)]
let v = &[1, 2, 3, 4, 5, 6][..];
{
let (left, right) = v.rsplit_array_ref::<0>();
assert_eq!(left, [1, 2, 3, 4, 5, 6]);
assert_eq!(right, &[]);
}
{
let (left, right) = v.rsplit_array_ref::<2>();
assert_eq!(left, [1, 2, 3, 4]);
assert_eq!(right, &[5, 6]);
}
{
let (left, right) = v.rsplit_array_ref::<6>();
assert_eq!(left, []);
assert_eq!(right, &[1, 2, 3, 4, 5, 6]);
}
sourcepub fn rsplit_array_mut<const N: usize>(&mut self) -> (&mut [T], &mut [T; N])
🔬This is a nightly-only experimental API. (split_array
)
pub fn rsplit_array_mut<const N: usize>(&mut self) -> (&mut [T], &mut [T; N])
split_array
)Divides one mutable slice into an array and a remainder slice at an index from the end.
The slice will contain all indices from [0, len - N)
(excluding
the index N
itself) and the array will contain all
indices from [len - N, len)
(excluding the index len
itself).
Panics
Panics if N > len
.
Examples
#![feature(split_array)]
let mut v = &mut [1, 0, 3, 0, 5, 6][..];
let (left, right) = v.rsplit_array_mut::<4>();
assert_eq!(left, [1, 0]);
assert_eq!(right, &mut [3, 0, 5, 6]);
left[1] = 2;
right[1] = 4;
assert_eq!(v, [1, 2, 3, 4, 5, 6]);
1.0.0 · sourcepub fn split<F>(&self, pred: F) -> Split<'_, T, F>where
F: FnMut(&T) -> bool,
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());
1.0.0 · sourcepub fn split_mut<F>(&mut self, pred: F) -> SplitMut<'_, T, F>where
F: FnMut(&T) -> bool,
pub fn split_mut<F>(&mut self, pred: F) -> SplitMut<'_, T, F>where
F: FnMut(&T) -> bool,
Returns an iterator over mutable subslices separated by elements that
match pred
. The matched element is not contained in the subslices.
Examples
let mut v = [10, 40, 30, 20, 60, 50];
for group in v.split_mut(|num| *num % 3 == 0) {
group[0] = 1;
}
assert_eq!(v, [1, 40, 30, 1, 60, 1]);
1.51.0 · sourcepub fn split_inclusive<F>(&self, pred: F) -> SplitInclusive<'_, T, F>where
F: FnMut(&T) -> bool,
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());
1.51.0 · sourcepub fn split_inclusive_mut<F>(&mut self, pred: F) -> SplitInclusiveMut<'_, T, F>where
F: FnMut(&T) -> bool,
pub fn split_inclusive_mut<F>(&mut self, pred: F) -> SplitInclusiveMut<'_, T, F>where
F: FnMut(&T) -> bool,
Returns an iterator over mutable subslices separated by elements that
match pred
. The matched element is contained in the previous
subslice as a terminator.
Examples
let mut v = [10, 40, 30, 20, 60, 50];
for group in v.split_inclusive_mut(|num| *num % 3 == 0) {
let terminator_idx = group.len()-1;
group[terminator_idx] = 1;
}
assert_eq!(v, [10, 40, 1, 20, 1, 1]);
1.27.0 · sourcepub fn rsplit<F>(&self, pred: F) -> RSplit<'_, T, F>where
F: FnMut(&T) -> bool,
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);
1.27.0 · sourcepub fn rsplit_mut<F>(&mut self, pred: F) -> RSplitMut<'_, T, F>where
F: FnMut(&T) -> bool,
pub fn rsplit_mut<F>(&mut self, pred: F) -> RSplitMut<'_, T, F>where
F: FnMut(&T) -> bool,
Returns an iterator over mutable 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 mut v = [100, 400, 300, 200, 600, 500];
let mut count = 0;
for group in v.rsplit_mut(|num| *num % 3 == 0) {
count += 1;
group[0] = count;
}
assert_eq!(v, [3, 400, 300, 2, 600, 1]);
1.0.0 · sourcepub fn splitn<F>(&self, n: usize, pred: F) -> SplitN<'_, T, F>where
F: FnMut(&T) -> bool,
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 · sourcepub fn splitn_mut<F>(&mut self, n: usize, pred: F) -> SplitNMut<'_, T, F>where
F: FnMut(&T) -> bool,
pub fn splitn_mut<F>(&mut self, n: usize, pred: F) -> SplitNMut<'_, T, F>where
F: FnMut(&T) -> bool,
Returns an iterator over mutable 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
let mut v = [10, 40, 30, 20, 60, 50];
for group in v.splitn_mut(2, |num| *num % 3 == 0) {
group[0] = 1;
}
assert_eq!(v, [1, 40, 30, 1, 60, 50]);
1.0.0 · sourcepub fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<'_, T, F>where
F: FnMut(&T) -> bool,
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:?}");
}
1.0.0 · sourcepub fn rsplitn_mut<F>(&mut self, n: usize, pred: F) -> RSplitNMut<'_, T, F>where
F: FnMut(&T) -> bool,
pub fn rsplitn_mut<F>(&mut self, n: usize, pred: F) -> RSplitNMut<'_, 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
let mut s = [10, 40, 30, 20, 60, 50];
for group in s.rsplitn_mut(2, |num| *num % 3 == 0) {
group[0] = 1;
}
assert_eq!(s, [1, 40, 30, 20, 60, 1]);
1.0.0 · sourcepub fn contains(&self, x: &T) -> boolwhere
T: PartialEq<T>,
pub fn contains(&self, x: &T) -> boolwhere
T: PartialEq<T>,
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 · sourcepub fn starts_with(&self, needle: &[T]) -> boolwhere
T: PartialEq<T>,
pub fn starts_with(&self, needle: &[T]) -> boolwhere
T: PartialEq<T>,
Returns true
if needle
is a prefix of the slice.
Examples
let v = [10, 40, 30];
assert!(v.starts_with(&[10]));
assert!(v.starts_with(&[10, 40]));
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 · sourcepub fn ends_with(&self, needle: &[T]) -> boolwhere
T: PartialEq<T>,
pub fn ends_with(&self, needle: &[T]) -> boolwhere
T: PartialEq<T>,
Returns true
if needle
is a suffix of the slice.
Examples
let v = [10, 40, 30];
assert!(v.ends_with(&[30]));
assert!(v.ends_with(&[40, 30]));
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 · sourcepub fn strip_prefix<P>(&self, prefix: &P) -> Option<&[T]>where
P: SlicePattern<Item = T> + ?Sized,
T: PartialEq<T>,
pub fn strip_prefix<P>(&self, prefix: &P) -> Option<&[T]>where
P: SlicePattern<Item = T> + ?Sized,
T: PartialEq<T>,
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 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(&[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 · sourcepub fn strip_suffix<P>(&self, suffix: &P) -> Option<&[T]>where
P: SlicePattern<Item = T> + ?Sized,
T: PartialEq<T>,
pub fn strip_suffix<P>(&self, suffix: &P) -> Option<&[T]>where
P: SlicePattern<Item = T> + ?Sized,
T: PartialEq<T>,
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 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(&[50]), None);
assert_eq!(v.strip_suffix(&[50, 30]), None);
1.0.0 · sourcepub fn binary_search(&self, x: &T) -> Result<usize, usize>where
T: Ord,
pub fn binary_search(&self, x: &T) -> Result<usize, usize>where
T: Ord,
Binary searches this slice for a given element.
This behaves similarly to contains
if this slice is sorted.
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);
// The above is equivalent to `let idx = s.binary_search(&num).unwrap_or_else(|x| x);`
s.insert(idx, num);
assert_eq!(s, [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 42, 55]);
1.0.0 · sourcepub fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize>where
F: FnMut(&'a T) -> Ordering,
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.
This behaves similarly to contains
if this slice is sorted.
The comparator function should implement an order consistent
with the sort order of the underlying slice, returning an
order code that indicates whether its argument is Less
,
Equal
or Greater
the desired target.
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 · sourcepub 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,
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.
This behaves similarly to contains
if this slice is sorted.
Assumes that the slice is sorted by the key, for instance with
sort_by_key
using the same key extraction function.
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, });
1.20.0 · sourcepub fn sort_unstable(&mut self)where
T: Ord,
pub fn sort_unstable(&mut self)where
T: Ord,
Sorts the slice, but might not preserve the order of equal elements.
This sort is unstable (i.e., may reorder equal elements), in-place (i.e., does not allocate), and O(n * log(n)) worst-case.
Current implementation
The current algorithm is based on pattern-defeating quicksort by Orson Peters, which combines the fast average case of randomized quicksort with the fast worst case of heapsort, while achieving linear time on slices with certain patterns. It uses some randomization to avoid degenerate cases, but with a fixed seed to always provide deterministic behavior.
It is typically faster than stable sorting, except in a few special cases, e.g., when the slice consists of several concatenated sorted sequences.
Examples
let mut v = [-5, 4, 1, -3, 2];
v.sort_unstable();
assert!(v == [-5, -3, 1, 2, 4]);
1.20.0 · sourcepub fn sort_unstable_by<F>(&mut self, compare: F)where
F: FnMut(&T, &T) -> Ordering,
pub fn sort_unstable_by<F>(&mut self, compare: F)where
F: FnMut(&T, &T) -> Ordering,
Sorts the slice with a comparator function, but might not preserve the order of equal elements.
This sort is unstable (i.e., may reorder equal elements), in-place (i.e., does not allocate), and O(n * log(n)) worst-case.
The comparator function must define a total ordering for the elements in the slice. If
the ordering is not total, the order of the elements is unspecified. An order is a
total order if it is (for all a
, b
and c
):
- total and antisymmetric: exactly one of
a < b
,a == b
ora > b
is true, and - transitive,
a < b
andb < c
impliesa < c
. The same must hold for both==
and>
.
For example, while f64
doesn’t implement Ord
because NaN != NaN
, we can use
partial_cmp
as our sort function when we know the slice doesn’t contain a NaN
.
let mut floats = [5f64, 4.0, 1.0, 3.0, 2.0];
floats.sort_unstable_by(|a, b| a.partial_cmp(b).unwrap());
assert_eq!(floats, [1.0, 2.0, 3.0, 4.0, 5.0]);
Current implementation
The current algorithm is based on pattern-defeating quicksort by Orson Peters, which combines the fast average case of randomized quicksort with the fast worst case of heapsort, while achieving linear time on slices with certain patterns. It uses some randomization to avoid degenerate cases, but with a fixed seed to always provide deterministic behavior.
It is typically faster than stable sorting, except in a few special cases, e.g., when the slice consists of several concatenated sorted sequences.
Examples
let mut v = [5, 4, 1, 3, 2];
v.sort_unstable_by(|a, b| a.cmp(b));
assert!(v == [1, 2, 3, 4, 5]);
// reverse sorting
v.sort_unstable_by(|a, b| b.cmp(a));
assert!(v == [5, 4, 3, 2, 1]);
1.20.0 · sourcepub fn sort_unstable_by_key<K, F>(&mut self, f: F)where
F: FnMut(&T) -> K,
K: Ord,
pub fn sort_unstable_by_key<K, F>(&mut self, f: F)where
F: FnMut(&T) -> K,
K: Ord,
Sorts the slice with a key extraction function, but might not preserve the order of equal elements.
This sort is unstable (i.e., may reorder equal elements), in-place (i.e., does not allocate), and O(m * n * log(n)) worst-case, where the key function is O(m).
Current implementation
The current algorithm is based on pattern-defeating quicksort by Orson Peters, which combines the fast average case of randomized quicksort with the fast worst case of heapsort, while achieving linear time on slices with certain patterns. It uses some randomization to avoid degenerate cases, but with a fixed seed to always provide deterministic behavior.
Due to its key calling strategy, sort_unstable_by_key
is likely to be slower than sort_by_cached_key
in
cases where the key function is expensive.
Examples
let mut v = [-5i32, 4, 1, -3, 2];
v.sort_unstable_by_key(|k| k.abs());
assert!(v == [1, 2, -3, 4, -5]);
1.49.0 · sourcepub fn select_nth_unstable(
&mut self,
index: usize
) -> (&mut [T], &mut T, &mut [T])where
T: Ord,
pub fn select_nth_unstable(
&mut self,
index: usize
) -> (&mut [T], &mut T, &mut [T])where
T: Ord,
Reorder the slice such that the element at index
is at its final sorted position.
This reordering has the additional property that any value at position i < index
will be
less than or equal to any value at a position j > index
. Additionally, this reordering is
unstable (i.e. any number of equal elements may end up at position index
), in-place
(i.e. does not allocate), and O(n) worst-case. This function is also/ known as “kth
element” in other libraries. It returns a triplet of the following from the reordered slice:
the subslice prior to index
, the element at index
, and the subslice after index
;
accordingly, the values in those two subslices will respectively all be less-than-or-equal-to
and greater-than-or-equal-to the value of the element at index
.
Current implementation
The current algorithm is based on the quickselect portion of the same quicksort algorithm
used for sort_unstable
.
Panics
Panics when index >= len()
, meaning it always panics on empty slices.
Examples
let mut v = [-5i32, 4, 1, -3, 2];
// Find the median
v.select_nth_unstable(2);
// We are only guaranteed the slice will be one of the following, based on the way we sort
// about the specified index.
assert!(v == [-3, -5, 1, 2, 4] ||
v == [-5, -3, 1, 2, 4] ||
v == [-3, -5, 1, 4, 2] ||
v == [-5, -3, 1, 4, 2]);
1.49.0 · sourcepub fn select_nth_unstable_by<F>(
&mut self,
index: usize,
compare: F
) -> (&mut [T], &mut T, &mut [T])where
F: FnMut(&T, &T) -> Ordering,
pub fn select_nth_unstable_by<F>(
&mut self,
index: usize,
compare: F
) -> (&mut [T], &mut T, &mut [T])where
F: FnMut(&T, &T) -> Ordering,
Reorder the slice with a comparator function such that the element at index
is at its
final sorted position.
This reordering has the additional property that any value at position i < index
will be
less than or equal to any value at a position j > index
using the comparator function.
Additionally, this reordering is unstable (i.e. any number of equal elements may end up at
position index
), in-place (i.e. does not allocate), and O(n) worst-case. This function
is also known as “kth element” in other libraries. It returns a triplet of the following from
the slice reordered according to the provided comparator function: the subslice prior to
index
, the element at index
, and the subslice after index
; accordingly, the values in
those two subslices will respectively all be less-than-or-equal-to and greater-than-or-equal-to
the value of the element at index
.
Current implementation
The current algorithm is based on the quickselect portion of the same quicksort algorithm
used for sort_unstable
.
Panics
Panics when index >= len()
, meaning it always panics on empty slices.
Examples
let mut v = [-5i32, 4, 1, -3, 2];
// Find the median as if the slice were sorted in descending order.
v.select_nth_unstable_by(2, |a, b| b.cmp(a));
// We are only guaranteed the slice will be one of the following, based on the way we sort
// about the specified index.
assert!(v == [2, 4, 1, -5, -3] ||
v == [2, 4, 1, -3, -5] ||
v == [4, 2, 1, -5, -3] ||
v == [4, 2, 1, -3, -5]);
1.49.0 · sourcepub fn select_nth_unstable_by_key<K, F>(
&mut self,
index: usize,
f: F
) -> (&mut [T], &mut T, &mut [T])where
F: FnMut(&T) -> K,
K: Ord,
pub fn select_nth_unstable_by_key<K, F>(
&mut self,
index: usize,
f: F
) -> (&mut [T], &mut T, &mut [T])where
F: FnMut(&T) -> K,
K: Ord,
Reorder the slice with a key extraction function such that the element at index
is at its
final sorted position.
This reordering has the additional property that any value at position i < index
will be
less than or equal to any value at a position j > index
using the key extraction function.
Additionally, this reordering is unstable (i.e. any number of equal elements may end up at
position index
), in-place (i.e. does not allocate), and O(n) worst-case. This function
is also known as “kth element” in other libraries. It returns a triplet of the following from
the slice reordered according to the provided key extraction function: the subslice prior to
index
, the element at index
, and the subslice after index
; accordingly, the values in
those two subslices will respectively all be less-than-or-equal-to and greater-than-or-equal-to
the value of the element at index
.
Current implementation
The current algorithm is based on the quickselect portion of the same quicksort algorithm
used for sort_unstable
.
Panics
Panics when index >= len()
, meaning it always panics on empty slices.
Examples
let mut v = [-5i32, 4, 1, -3, 2];
// Return the median as if the array were sorted according to absolute value.
v.select_nth_unstable_by_key(2, |a| a.abs());
// We are only guaranteed the slice will be one of the following, based on the way we sort
// about the specified index.
assert!(v == [1, 2, -3, 4, -5] ||
v == [1, 2, -3, -5, 4] ||
v == [2, 1, -3, 4, -5] ||
v == [2, 1, -3, -5, 4]);
sourcepub fn partition_dedup(&mut self) -> (&mut [T], &mut [T])where
T: PartialEq<T>,
🔬This is a nightly-only experimental API. (slice_partition_dedup
)
pub fn partition_dedup(&mut self) -> (&mut [T], &mut [T])where
T: PartialEq<T>,
slice_partition_dedup
)Moves all consecutive repeated elements to the end of the slice according to the
PartialEq
trait implementation.
Returns two slices. The first contains no consecutive repeated elements. The second contains all the duplicates in no specified order.
If the slice is sorted, the first returned slice contains no duplicates.
Examples
#![feature(slice_partition_dedup)]
let mut slice = [1, 2, 2, 3, 3, 2, 1, 1];
let (dedup, duplicates) = slice.partition_dedup();
assert_eq!(dedup, [1, 2, 3, 2, 1]);
assert_eq!(duplicates, [2, 3, 1]);
sourcepub fn partition_dedup_by<F>(&mut self, same_bucket: F) -> (&mut [T], &mut [T])where
F: FnMut(&mut T, &mut T) -> bool,
🔬This is a nightly-only experimental API. (slice_partition_dedup
)
pub fn partition_dedup_by<F>(&mut self, same_bucket: F) -> (&mut [T], &mut [T])where
F: FnMut(&mut T, &mut T) -> bool,
slice_partition_dedup
)Moves all but the first of consecutive elements to the end of the slice satisfying a given equality relation.
Returns two slices. The first contains no consecutive repeated elements. The second contains all the duplicates in no specified order.
The same_bucket
function is passed references to two elements from the slice and
must determine if the elements compare equal. The elements are passed in opposite order
from their order in the slice, so if same_bucket(a, b)
returns true
, a
is moved
at the end of the slice.
If the slice is sorted, the first returned slice contains no duplicates.
Examples
#![feature(slice_partition_dedup)]
let mut slice = ["foo", "Foo", "BAZ", "Bar", "bar", "baz", "BAZ"];
let (dedup, duplicates) = slice.partition_dedup_by(|a, b| a.eq_ignore_ascii_case(b));
assert_eq!(dedup, ["foo", "BAZ", "Bar", "baz"]);
assert_eq!(duplicates, ["bar", "Foo", "BAZ"]);
sourcepub fn partition_dedup_by_key<K, F>(&mut self, key: F) -> (&mut [T], &mut [T])where
F: FnMut(&mut T) -> K,
K: PartialEq<K>,
🔬This is a nightly-only experimental API. (slice_partition_dedup
)
pub fn partition_dedup_by_key<K, F>(&mut self, key: F) -> (&mut [T], &mut [T])where
F: FnMut(&mut T) -> K,
K: PartialEq<K>,
slice_partition_dedup
)Moves all but the first of consecutive elements to the end of the slice that resolve to the same key.
Returns two slices. The first contains no consecutive repeated elements. The second contains all the duplicates in no specified order.
If the slice is sorted, the first returned slice contains no duplicates.
Examples
#![feature(slice_partition_dedup)]
let mut slice = [10, 20, 21, 30, 30, 20, 11, 13];
let (dedup, duplicates) = slice.partition_dedup_by_key(|i| *i / 10);
assert_eq!(dedup, [10, 20, 30, 20, 11]);
assert_eq!(duplicates, [21, 30, 13]);
1.26.0 · sourcepub fn rotate_left(&mut self, mid: usize)
pub fn rotate_left(&mut self, mid: usize)
Rotates the slice in-place such that the first mid
elements of the
slice move to the end while the last self.len() - mid
elements move to
the front. After calling rotate_left
, the element previously at index
mid
will become the first element in the slice.
Panics
This function will panic if mid
is greater than the length of the
slice. Note that mid == self.len()
does not panic and is a no-op
rotation.
Complexity
Takes linear (in self.len()
) time.
Examples
let mut a = ['a', 'b', 'c', 'd', 'e', 'f'];
a.rotate_left(2);
assert_eq!(a, ['c', 'd', 'e', 'f', 'a', 'b']);
Rotating a subslice:
let mut a = ['a', 'b', 'c', 'd', 'e', 'f'];
a[1..5].rotate_left(1);
assert_eq!(a, ['a', 'c', 'd', 'e', 'b', 'f']);
1.26.0 · sourcepub fn rotate_right(&mut self, k: usize)
pub fn rotate_right(&mut self, k: usize)
Rotates the slice in-place such that the first self.len() - k
elements of the slice move to the end while the last k
elements move
to the front. After calling rotate_right
, the element previously at
index self.len() - k
will become the first element in the slice.
Panics
This function will panic if k
is greater than the length of the
slice. Note that k == self.len()
does not panic and is a no-op
rotation.
Complexity
Takes linear (in self.len()
) time.
Examples
let mut a = ['a', 'b', 'c', 'd', 'e', 'f'];
a.rotate_right(2);
assert_eq!(a, ['e', 'f', 'a', 'b', 'c', 'd']);
Rotate a subslice:
let mut a = ['a', 'b', 'c', 'd', 'e', 'f'];
a[1..5].rotate_right(1);
assert_eq!(a, ['a', 'e', 'b', 'c', 'd', 'f']);
1.50.0 · sourcepub fn fill(&mut self, value: T)where
T: Clone,
pub fn fill(&mut self, value: T)where
T: Clone,
Fills self
with elements by cloning value
.
Examples
let mut buf = vec![0; 10];
buf.fill(1);
assert_eq!(buf, vec![1; 10]);
1.51.0 · sourcepub fn fill_with<F>(&mut self, f: F)where
F: FnMut() -> T,
pub fn fill_with<F>(&mut self, f: F)where
F: FnMut() -> T,
Fills self
with elements returned by calling a closure repeatedly.
This method uses a closure to create new values. If you’d rather
Clone
a given value, use fill
. If you want to use the Default
trait to generate values, you can pass Default::default
as the
argument.
Examples
let mut buf = vec![1; 10];
buf.fill_with(Default::default);
assert_eq!(buf, vec![0; 10]);
1.7.0 · sourcepub fn clone_from_slice(&mut self, src: &[T])where
T: Clone,
pub fn clone_from_slice(&mut self, src: &[T])where
T: Clone,
Copies the elements from src
into self
.
The length of src
must be the same as self
.
Panics
This function will panic if the two slices have different lengths.
Examples
Cloning two elements from a slice into another:
let src = [1, 2, 3, 4];
let mut dst = [0, 0];
// Because the slices have to be the same length,
// we slice the source slice from four elements
// to two. It will panic if we don't do this.
dst.clone_from_slice(&src[2..]);
assert_eq!(src, [1, 2, 3, 4]);
assert_eq!(dst, [3, 4]);
Rust enforces that there can only be one mutable reference with no
immutable references to a particular piece of data in a particular
scope. Because of this, attempting to use clone_from_slice
on a
single slice will result in a compile failure:
let mut slice = [1, 2, 3, 4, 5];
slice[..2].clone_from_slice(&slice[3..]); // compile fail!
To work around this, we can use split_at_mut
to create two distinct
sub-slices from a slice:
let mut slice = [1, 2, 3, 4, 5];
{
let (left, right) = slice.split_at_mut(2);
left.clone_from_slice(&right[1..]);
}
assert_eq!(slice, [4, 5, 3, 4, 5]);
1.9.0 · sourcepub fn copy_from_slice(&mut self, src: &[T])where
T: Copy,
pub fn copy_from_slice(&mut self, src: &[T])where
T: Copy,
Copies all elements from src
into self
, using a memcpy.
The length of src
must be the same as self
.
If T
does not implement Copy
, use clone_from_slice
.
Panics
This function will panic if the two slices have different lengths.
Examples
Copying two elements from a slice into another:
let src = [1, 2, 3, 4];
let mut dst = [0, 0];
// Because the slices have to be the same length,
// we slice the source slice from four elements
// to two. It will panic if we don't do this.
dst.copy_from_slice(&src[2..]);
assert_eq!(src, [1, 2, 3, 4]);
assert_eq!(dst, [3, 4]);
Rust enforces that there can only be one mutable reference with no
immutable references to a particular piece of data in a particular
scope. Because of this, attempting to use copy_from_slice
on a
single slice will result in a compile failure:
let mut slice = [1, 2, 3, 4, 5];
slice[..2].copy_from_slice(&slice[3..]); // compile fail!
To work around this, we can use split_at_mut
to create two distinct
sub-slices from a slice:
let mut slice = [1, 2, 3, 4, 5];
{
let (left, right) = slice.split_at_mut(2);
left.copy_from_slice(&right[1..]);
}
assert_eq!(slice, [4, 5, 3, 4, 5]);
1.37.0 · sourcepub fn copy_within<R>(&mut self, src: R, dest: usize)where
R: RangeBounds<usize>,
T: Copy,
pub fn copy_within<R>(&mut self, src: R, dest: usize)where
R: RangeBounds<usize>,
T: Copy,
Copies elements from one part of the slice to another part of itself, using a memmove.
src
is the range within self
to copy from. dest
is the starting
index of the range within self
to copy to, which will have the same
length as src
. The two ranges may overlap. The ends of the two ranges
must be less than or equal to self.len()
.
Panics
This function will panic if either range exceeds the end of the slice,
or if the end of src
is before the start.
Examples
Copying four bytes within a slice:
let mut bytes = *b"Hello, World!";
bytes.copy_within(1..5, 8);
assert_eq!(&bytes, b"Hello, Wello!");
1.27.0 · sourcepub fn swap_with_slice(&mut self, other: &mut [T])
pub fn swap_with_slice(&mut self, other: &mut [T])
Swaps all elements in self
with those in other
.
The length of other
must be the same as self
.
Panics
This function will panic if the two slices have different lengths.
Example
Swapping two elements across slices:
let mut slice1 = [0, 0];
let mut slice2 = [1, 2, 3, 4];
slice1.swap_with_slice(&mut slice2[2..]);
assert_eq!(slice1, [3, 4]);
assert_eq!(slice2, [1, 2, 0, 0]);
Rust enforces that there can only be one mutable reference to a
particular piece of data in a particular scope. Because of this,
attempting to use swap_with_slice
on a single slice will result in
a compile failure:
let mut slice = [1, 2, 3, 4, 5];
slice[..2].swap_with_slice(&mut slice[3..]); // compile fail!
To work around this, we can use split_at_mut
to create two distinct
mutable sub-slices from a slice:
let mut slice = [1, 2, 3, 4, 5];
{
let (left, right) = slice.split_at_mut(2);
left.swap_with_slice(&mut right[1..]);
}
assert_eq!(slice, [4, 5, 3, 1, 2]);
1.30.0 · sourcepub unsafe fn align_to<U>(&self) -> (&[T], &[U], &[T])
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 method may make the middle slice the greatest length possible for a given type and input slice, but only your algorithm’s performance should depend on that, not its correctness. It is permissible for all of the input data to be returned as the prefix or suffix slice.
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);
}
1.30.0 · sourcepub unsafe fn align_to_mut<U>(&mut self) -> (&mut [T], &mut [U], &mut [T])
pub unsafe fn align_to_mut<U>(&mut self) -> (&mut [T], &mut [U], &mut [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 method may make the middle slice the greatest length possible for a given type and input slice, but only your algorithm’s performance should depend on that, not its correctness. It is permissible for all of the input data to be returned as the prefix or suffix slice.
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 mut bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7];
let (prefix, shorts, suffix) = bytes.align_to_mut::<u16>();
// less_efficient_algorithm_for_bytes(prefix);
// more_efficient_algorithm_for_aligned_shorts(shorts);
// less_efficient_algorithm_for_bytes(suffix);
}
sourcepub 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
)
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,
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 has the same weak
postconditions as that method. You’re only assured that
self.len() == prefix.len() + middle.len() * LANES + suffix.len()
.
Notably, all of the following are possible:
prefix.len() >= LANES
.middle.is_empty()
despiteself.len() >= 3 * LANES
.suffix.len() >= LANES
.
That said, this is a safe method, so if you’re only writing safe code, then this can at most cause incorrect logic, not unsoundness.
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::SimdFloat;
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;
use std::simd::f32x4;
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);
sourcepub fn as_simd_mut<const LANES: usize>(
&mut self
) -> (&mut [T], &mut [Simd<T, LANES>], &mut [T])where
Simd<T, LANES>: AsMut<[T; LANES]>,
T: SimdElement,
LaneCount<LANES>: SupportedLaneCount,
🔬This is a nightly-only experimental API. (portable_simd
)
pub fn as_simd_mut<const LANES: usize>(
&mut self
) -> (&mut [T], &mut [Simd<T, LANES>], &mut [T])where
Simd<T, LANES>: AsMut<[T; LANES]>,
T: SimdElement,
LaneCount<LANES>: SupportedLaneCount,
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_mut
, so has the same weak
postconditions as that method. You’re only assured that
self.len() == prefix.len() + middle.len() * LANES + suffix.len()
.
Notably, all of the following are possible:
prefix.len() >= LANES
.middle.is_empty()
despiteself.len() >= 3 * LANES
.suffix.len() >= LANES
.
That said, this is a safe method, so if you’re only writing safe code, then this can at most cause incorrect logic, not unsoundness.
This is the mutable version of slice::as_simd
; see that for examples.
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
.
sourcepub fn is_sorted(&self) -> boolwhere
T: PartialOrd<T>,
🔬This is a nightly-only experimental API. (is_sorted
)
pub fn is_sorted(&self) -> boolwhere
T: PartialOrd<T>,
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());
sourcepub fn is_sorted_by<F>(&self, compare: F) -> boolwhere
F: FnMut(&T, &T) -> Option<Ordering>,
🔬This is a nightly-only experimental API. (is_sorted
)
pub fn is_sorted_by<F>(&self, compare: F) -> boolwhere
F: FnMut(&T, &T) -> Option<Ordering>,
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 the ordering of two elements. Apart from that, it’s equivalent to
is_sorted
; see its documentation for more information.
sourcepub fn is_sorted_by_key<F, K>(&self, f: F) -> boolwhere
F: FnMut(&T) -> K,
K: PartialOrd<K>,
🔬This is a nightly-only experimental API. (is_sorted
)
pub fn is_sorted_by_key<F, K>(&self, f: F) -> boolwhere
F: FnMut(&T) -> K,
K: PartialOrd<K>,
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 · sourcepub fn partition_point<P>(&self, pred: P) -> usizewhere
P: FnMut(&T) -> bool,
pub fn partition_point<P>(&self, pred: P) -> usizewhere
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 a 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]);
sourcepub fn take<R>(self: &mut &'a [T], range: R) -> Option<&'a [T]>where
R: OneSidedRange<usize>,
🔬This is a nightly-only experimental API. (slice_take
)
pub fn take<R>(self: &mut &'a [T], range: R) -> Option<&'a [T]>where
R: OneSidedRange<usize>,
slice_take
)Removes the subslice corresponding to the given range and returns a reference to it.
Returns None
and does not modify the slice if the given
range is out of bounds.
Note that this method only accepts one-sided ranges such as
2..
or ..6
, but not 2..6
.
Examples
Taking the first three elements of a slice:
#![feature(slice_take)]
let mut slice: &[_] = &['a', 'b', 'c', 'd'];
let mut first_three = slice.take(..3).unwrap();
assert_eq!(slice, &['d']);
assert_eq!(first_three, &['a', 'b', 'c']);
Taking the last two elements of a slice:
#![feature(slice_take)]
let mut slice: &[_] = &['a', 'b', 'c', 'd'];
let mut tail = slice.take(2..).unwrap();
assert_eq!(slice, &['a', 'b']);
assert_eq!(tail, &['c', 'd']);
Getting None
when range
is out of bounds:
#![feature(slice_take)]
let mut slice: &[_] = &['a', 'b', 'c', 'd'];
assert_eq!(None, slice.take(5..));
assert_eq!(None, slice.take(..5));
assert_eq!(None, slice.take(..=4));
let expected: &[char] = &['a', 'b', 'c', 'd'];
assert_eq!(Some(expected), slice.take(..4));
sourcepub fn take_mut<R>(self: &mut &'a mut [T], range: R) -> Option<&'a mut [T]>where
R: OneSidedRange<usize>,
🔬This is a nightly-only experimental API. (slice_take
)
pub fn take_mut<R>(self: &mut &'a mut [T], range: R) -> Option<&'a mut [T]>where
R: OneSidedRange<usize>,
slice_take
)Removes the subslice corresponding to the given range and returns a mutable reference to it.
Returns None
and does not modify the slice if the given
range is out of bounds.
Note that this method only accepts one-sided ranges such as
2..
or ..6
, but not 2..6
.
Examples
Taking the first three elements of a slice:
#![feature(slice_take)]
let mut slice: &mut [_] = &mut ['a', 'b', 'c', 'd'];
let mut first_three = slice.take_mut(..3).unwrap();
assert_eq!(slice, &mut ['d']);
assert_eq!(first_three, &mut ['a', 'b', 'c']);
Taking the last two elements of a slice:
#![feature(slice_take)]
let mut slice: &mut [_] = &mut ['a', 'b', 'c', 'd'];
let mut tail = slice.take_mut(2..).unwrap();
assert_eq!(slice, &mut ['a', 'b']);
assert_eq!(tail, &mut ['c', 'd']);
Getting None
when range
is out of bounds:
#![feature(slice_take)]
let mut slice: &mut [_] = &mut ['a', 'b', 'c', 'd'];
assert_eq!(None, slice.take_mut(5..));
assert_eq!(None, slice.take_mut(..5));
assert_eq!(None, slice.take_mut(..=4));
let expected: &mut [_] = &mut ['a', 'b', 'c', 'd'];
assert_eq!(Some(expected), slice.take_mut(..4));
sourcepub fn take_first(self: &mut &'a [T]) -> Option<&'a T>
🔬This is a nightly-only experimental API. (slice_take
)
pub fn take_first(self: &mut &'a [T]) -> Option<&'a T>
slice_take
)Removes the first element of the slice and returns a reference to it.
Returns None
if the slice is empty.
Examples
#![feature(slice_take)]
let mut slice: &[_] = &['a', 'b', 'c'];
let first = slice.take_first().unwrap();
assert_eq!(slice, &['b', 'c']);
assert_eq!(first, &'a');
sourcepub fn take_first_mut(self: &mut &'a mut [T]) -> Option<&'a mut T>
🔬This is a nightly-only experimental API. (slice_take
)
pub fn take_first_mut(self: &mut &'a mut [T]) -> Option<&'a mut T>
slice_take
)Removes the first element of the slice and returns a mutable reference to it.
Returns None
if the slice is empty.
Examples
#![feature(slice_take)]
let mut slice: &mut [_] = &mut ['a', 'b', 'c'];
let first = slice.take_first_mut().unwrap();
*first = 'd';
assert_eq!(slice, &['b', 'c']);
assert_eq!(first, &'d');
sourcepub fn take_last(self: &mut &'a [T]) -> Option<&'a T>
🔬This is a nightly-only experimental API. (slice_take
)
pub fn take_last(self: &mut &'a [T]) -> Option<&'a T>
slice_take
)Removes the last element of the slice and returns a reference to it.
Returns None
if the slice is empty.
Examples
#![feature(slice_take)]
let mut slice: &[_] = &['a', 'b', 'c'];
let last = slice.take_last().unwrap();
assert_eq!(slice, &['a', 'b']);
assert_eq!(last, &'c');
sourcepub fn take_last_mut(self: &mut &'a mut [T]) -> Option<&'a mut T>
🔬This is a nightly-only experimental API. (slice_take
)
pub fn take_last_mut(self: &mut &'a mut [T]) -> Option<&'a mut T>
slice_take
)Removes the last element of the slice and returns a mutable reference to it.
Returns None
if the slice is empty.
Examples
#![feature(slice_take)]
let mut slice: &mut [_] = &mut ['a', 'b', 'c'];
let last = slice.take_last_mut().unwrap();
*last = 'd';
assert_eq!(slice, &['a', 'b']);
assert_eq!(last, &'d');
sourcepub fn sort_floats(&mut self)
🔬This is a nightly-only experimental API. (sort_floats
)
pub fn sort_floats(&mut self)
sort_floats
)Sorts the slice of floats.
This sort is in-place (i.e. does not allocate), O(n * log(n)) worst-case, and uses
the ordering defined by f32::total_cmp
.
Current implementation
This uses the same sorting algorithm as sort_unstable_by
.
Examples
#![feature(sort_floats)]
let mut v = [2.6, -5e-8, f32::NAN, 8.29, f32::INFINITY, -1.0, 0.0, -f32::INFINITY, -0.0];
v.sort_floats();
let sorted = [-f32::INFINITY, -1.0, -5e-8, -0.0, 0.0, 2.6, 8.29, f32::INFINITY, f32::NAN];
assert_eq!(&v[..8], &sorted[..8]);
assert!(v[8].is_nan());
1.23.0 · sourcepub fn is_ascii(&self) -> bool
pub fn is_ascii(&self) -> bool
Checks if all bytes in this slice are within the ASCII range.
1.23.0 · sourcepub fn eq_ignore_ascii_case(&self, other: &[u8]) -> bool
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.
1.23.0 · sourcepub fn make_ascii_uppercase(&mut self)
pub fn make_ascii_uppercase(&mut self)
Converts this slice to its ASCII upper case equivalent in-place.
ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.
To return a new uppercased value without modifying the existing one, use
to_ascii_uppercase
.
1.23.0 · sourcepub fn make_ascii_lowercase(&mut self)
pub fn make_ascii_lowercase(&mut self)
Converts this slice to its ASCII lower case equivalent in-place.
ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.
To return a new lowercased value without modifying the existing one, use
to_ascii_lowercase
.
1.60.0 · sourcepub fn escape_ascii(&self) -> EscapeAscii<'_>
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");
sourcepub fn trim_ascii_start(&self) -> &[u8]
🔬This is a nightly-only experimental API. (byte_slice_trim_ascii
)
pub fn trim_ascii_start(&self) -> &[u8]
byte_slice_trim_ascii
)Returns a byte slice with leading ASCII whitespace bytes removed.
‘Whitespace’ refers to the definition used by
u8::is_ascii_whitespace
.
Examples
#![feature(byte_slice_trim_ascii)]
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"");
sourcepub fn trim_ascii_end(&self) -> &[u8]
🔬This is a nightly-only experimental API. (byte_slice_trim_ascii
)
pub fn trim_ascii_end(&self) -> &[u8]
byte_slice_trim_ascii
)Returns a byte slice with trailing ASCII whitespace bytes removed.
‘Whitespace’ refers to the definition used by
u8::is_ascii_whitespace
.
Examples
#![feature(byte_slice_trim_ascii)]
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"");
sourcepub fn trim_ascii(&self) -> &[u8]
🔬This is a nightly-only experimental API. (byte_slice_trim_ascii
)
pub fn trim_ascii(&self) -> &[u8]
byte_slice_trim_ascii
)Returns a byte slice with leading and trailing ASCII whitespace bytes removed.
‘Whitespace’ refers to the definition used by
u8::is_ascii_whitespace
.
Examples
#![feature(byte_slice_trim_ascii)]
assert_eq!(b"\r hello world\n ".trim_ascii(), b"hello world");
assert_eq!(b" ".trim_ascii(), b"");
assert_eq!(b"".trim_ascii(), b"");
sourcepub fn flatten(&self) -> &[T]
🔬This is a nightly-only experimental API. (slice_flatten
)
pub fn flatten(&self) -> &[T]
slice_flatten
)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
#![feature(slice_flatten)]
assert_eq!([[1, 2, 3], [4, 5, 6]].flatten(), &[1, 2, 3, 4, 5, 6]);
assert_eq!(
[[1, 2, 3], [4, 5, 6]].flatten(),
[[1, 2], [3, 4], [5, 6]].flatten(),
);
let slice_of_empty_arrays: &[[i32; 0]] = &[[], [], [], [], []];
assert!(slice_of_empty_arrays.flatten().is_empty());
let empty_slice_of_arrays: &[[u32; 10]] = &[];
assert!(empty_slice_of_arrays.flatten().is_empty());
sourcepub fn flatten_mut(&mut self) -> &mut [T]
🔬This is a nightly-only experimental API. (slice_flatten
)
pub fn flatten_mut(&mut self) -> &mut [T]
slice_flatten
)Takes a &mut [[T; N]]
, and flattens it to a &mut [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
#![feature(slice_flatten)]
fn add_5_to_all(slice: &mut [i32]) {
for i in slice {
*i += 5;
}
}
let mut array = [[1, 2, 3], [4, 5, 6], [7, 8, 9]];
add_5_to_all(array.flatten_mut());
assert_eq!(array, [[6, 7, 8], [9, 10, 11], [12, 13, 14]]);
sourcepub fn sort_floats(&mut self)
🔬This is a nightly-only experimental API. (sort_floats
)
pub fn sort_floats(&mut self)
sort_floats
)Sorts the slice of floats.
This sort is in-place (i.e. does not allocate), O(n * log(n)) worst-case, and uses
the ordering defined by f64::total_cmp
.
Current implementation
This uses the same sorting algorithm as sort_unstable_by
.
Examples
#![feature(sort_floats)]
let mut v = [2.6, -5e-8, f64::NAN, 8.29, f64::INFINITY, -1.0, 0.0, -f64::INFINITY, -0.0];
v.sort_floats();
let sorted = [-f64::INFINITY, -1.0, -5e-8, -0.0, 0.0, 2.6, 8.29, f64::INFINITY, f64::NAN];
assert_eq!(&v[..8], &sorted[..8]);
assert!(v[8].is_nan());
Trait Implementations
sourceimpl AsMut<[u8; 48]> for Sha384Hash
impl AsMut<[u8; 48]> for Sha384Hash
sourceimpl AsRef<[u8; 48]> for Sha384Hash
impl AsRef<[u8; 48]> for Sha384Hash
sourceimpl Clone for Sha384Hash
impl Clone for Sha384Hash
sourcefn clone(&self) -> Sha384Hash
fn clone(&self) -> Sha384Hash
1.0.0 · sourceconst fn clone_from(&mut self, source: &Self)
const fn clone_from(&mut self, source: &Self)
source
. Read more