1.36.0[−][src]Struct std::io::IoSliceMut
A buffer type used with Read::read_vectored
.
It is semantically a wrapper around an &mut [u8]
, but is guaranteed to be
ABI compatible with the iovec
type on Unix platforms and WSABUF
on
Windows.
Methods
impl<'a> IoSliceMut<'a>
[src]
pub fn new(buf: &'a mut [u8]) -> IoSliceMut<'a>
[src]
Creates a new IoSliceMut
wrapping a byte slice.
Panics
Panics on Windows if the slice is larger than 4GB.
Methods from Deref<Target = [u8]>
pub fn len(&self) -> usize
1.0.0[src]
pub fn is_empty(&self) -> bool
1.0.0[src]
pub fn first(&self) -> Option<&T>
1.0.0[src]
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());Run
pub fn first_mut(&mut self) -> Option<&mut T>
1.0.0[src]
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]);Run
pub fn split_first(&self) -> Option<(&T, &[T])>
1.5.0[src]
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]); }Run
pub fn split_first_mut(&mut self) -> Option<(&mut T, &mut [T])>
1.5.0[src]
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]);Run
pub fn split_last(&self) -> Option<(&T, &[T])>
1.5.0[src]
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]); }Run
pub fn split_last_mut(&mut self) -> Option<(&mut T, &mut [T])>
1.5.0[src]
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]);Run
pub fn last(&self) -> Option<&T>
1.0.0[src]
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());Run
pub fn last_mut(&mut self) -> Option<&mut T>
1.0.0[src]
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]);Run
pub fn get<I>(&self, index: I) -> Option<&<I as SliceIndex<[T]>>::Output> where
I: SliceIndex<[T]>,
1.0.0[src]
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));Run
pub fn get_mut<I>(
&mut self,
index: I
) -> Option<&mut <I as SliceIndex<[T]>>::Output> where
I: SliceIndex<[T]>,
1.0.0[src]
&mut self,
index: I
) -> Option<&mut <I as SliceIndex<[T]>>::Output> where
I: SliceIndex<[T]>,
Returns a mutable reference to an element or subslice depending on the
type of index (see get
) or None
if the index is out of bounds.
Examples
let x = &mut [0, 1, 2]; if let Some(elem) = x.get_mut(1) { *elem = 42; } assert_eq!(x, &[0, 42, 2]);Run
pub unsafe fn get_unchecked<I>(
&self,
index: I
) -> &<I as SliceIndex<[T]>>::Output where
I: SliceIndex<[T]>,
1.0.0[src]
&self,
index: I
) -> &<I as SliceIndex<[T]>>::Output where
I: SliceIndex<[T]>,
Returns a reference to an element or subslice, without doing bounds checking.
This is generally not recommended, use with caution! For a safe
alternative see get
.
Examples
let x = &[1, 2, 4]; unsafe { assert_eq!(x.get_unchecked(1), &2); }Run
pub unsafe fn get_unchecked_mut<I>(
&mut self,
index: I
) -> &mut <I as SliceIndex<[T]>>::Output where
I: SliceIndex<[T]>,
1.0.0[src]
&mut self,
index: I
) -> &mut <I as SliceIndex<[T]>>::Output where
I: SliceIndex<[T]>,
Returns a mutable reference to an element or subslice, without doing bounds checking.
This is generally not recommended, use with caution! For a safe
alternative see get_mut
.
Examples
let x = &mut [1, 2, 4]; unsafe { let elem = x.get_unchecked_mut(1); *elem = 13; } assert_eq!(x, &[1, 13, 4]);Run
pub const fn as_ptr(&self) -> *const T
1.0.0[src]
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)); } }Run
pub fn as_mut_ptr(&mut self) -> *mut T
1.0.0[src]
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]);Run
pub fn swap(&mut self, a: usize, b: usize)
1.0.0[src]
Swaps two elements in the slice.
Arguments
- a - The index of the first element
- b - The index of the second element
Panics
Panics if a
or b
are out of bounds.
Examples
let mut v = ["a", "b", "c", "d"]; v.swap(1, 3); assert!(v == ["a", "d", "c", "b"]);Run
pub fn reverse(&mut self)
1.0.0[src]
Reverses the order of elements in the slice, in place.
Examples
let mut v = [1, 2, 3]; v.reverse(); assert!(v == [3, 2, 1]);Run
ⓘImportant traits for Iter<'a, T>pub fn iter(&self) -> Iter<T>
1.0.0[src]
Returns an iterator over the slice.
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);Run
ⓘImportant traits for IterMut<'a, T>pub fn iter_mut(&mut self) -> IterMut<T>
1.0.0[src]
Returns an iterator that allows modifying each value.
Examples
let x = &mut [1, 2, 4]; for elem in x.iter_mut() { *elem += 2; } assert_eq!(x, &[3, 4, 6]);Run
ⓘImportant traits for Windows<'a, T>pub fn windows(&self, size: usize) -> Windows<T>
1.0.0[src]
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());Run
If the slice is shorter than size
:
let slice = ['f', 'o', 'o']; let mut iter = slice.windows(4); assert!(iter.next().is_none());Run
ⓘImportant traits for Chunks<'a, T>pub fn chunks(&self, chunk_size: usize) -> Chunks<T>
1.0.0[src]
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 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());Run
ⓘImportant traits for ChunksMut<'a, T>pub fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<T>
1.0.0[src]
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 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]);Run
ⓘImportant traits for ChunksExact<'a, T>pub fn chunks_exact(&self, chunk_size: usize) -> ChunksExact<T>
1.31.0[src]
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']);Run
ⓘImportant traits for ChunksExactMut<'a, T>pub fn chunks_exact_mut(&mut self, chunk_size: usize) -> ChunksExactMut<T>
1.31.0[src]
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 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]);Run
ⓘImportant traits for RChunks<'a, T>pub fn rchunks(&self, chunk_size: usize) -> RChunks<T>
1.31.0[src]
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());Run
ⓘImportant traits for RChunksMut<'a, T>pub fn rchunks_mut(&mut self, chunk_size: usize) -> RChunksMut<T>
1.31.0[src]
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]);Run
ⓘImportant traits for RChunksExact<'a, T>pub fn rchunks_exact(&self, chunk_size: usize) -> RChunksExact<T>
1.31.0[src]
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 chunks
.
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']);Run
ⓘImportant traits for RChunksExactMut<'a, T>pub fn rchunks_exact_mut(&mut self, chunk_size: usize) -> RChunksExactMut<T>
1.31.0[src]
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]);Run
pub fn split_at(&self, mid: usize) -> (&[T], &[T])
1.0.0[src]
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!(left == []); assert!(right == [1, 2, 3, 4, 5, 6]); } { let (left, right) = v.split_at(2); assert!(left == [1, 2]); assert!(right == [3, 4, 5, 6]); } { let (left, right) = v.split_at(6); assert!(left == [1, 2, 3, 4, 5, 6]); assert!(right == []); }Run
pub fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T])
1.0.0[src]
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]; // scoped to restrict the lifetime of the borrows { let (left, right) = v.split_at_mut(2); assert!(left == [1, 0]); assert!(right == [3, 0, 5, 6]); left[1] = 2; right[1] = 4; } assert!(v == [1, 2, 3, 4, 5, 6]);Run
ⓘImportant traits for Split<'a, T, P>pub fn split<F>(&self, pred: F) -> Split<T, F> where
F: FnMut(&T) -> bool,
1.0.0[src]
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());Run
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());Run
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());Run
ⓘImportant traits for SplitMut<'a, T, P>pub fn split_mut<F>(&mut self, pred: F) -> SplitMut<T, F> where
F: FnMut(&T) -> bool,
1.0.0[src]
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]);Run
ⓘImportant traits for RSplit<'a, T, P>pub fn rsplit<F>(&self, pred: F) -> RSplit<T, F> where
F: FnMut(&T) -> bool,
1.27.0[src]
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);Run
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);Run
ⓘImportant traits for RSplitMut<'a, T, P>pub fn rsplit_mut<F>(&mut self, pred: F) -> RSplitMut<T, F> where
F: FnMut(&T) -> bool,
1.27.0[src]
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]);Run
ⓘImportant traits for SplitN<'a, T, P>pub fn splitn<F>(&self, n: usize, pred: F) -> SplitN<T, F> where
F: FnMut(&T) -> bool,
1.0.0[src]
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); }Run
ⓘImportant traits for SplitNMut<'a, T, P>pub fn splitn_mut<F>(&mut self, n: usize, pred: F) -> SplitNMut<T, F> where
F: FnMut(&T) -> bool,
1.0.0[src]
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
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]);Run
ⓘImportant traits for RSplitN<'a, T, P>pub fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<T, F> where
F: FnMut(&T) -> bool,
1.0.0[src]
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); }Run
ⓘImportant traits for RSplitNMut<'a, T, P>pub fn rsplitn_mut<F>(&mut self, n: usize, pred: F) -> RSplitNMut<T, F> where
F: FnMut(&T) -> bool,
1.0.0[src]
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]);Run
pub fn contains(&self, x: &T) -> bool where
T: PartialEq<T>,
1.0.0[src]
T: PartialEq<T>,
Returns true
if the slice contains an element with the given value.
Examples
let v = [10, 40, 30]; assert!(v.contains(&30)); assert!(!v.contains(&50));Run
pub fn starts_with(&self, needle: &[T]) -> bool where
T: PartialEq<T>,
1.0.0[src]
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]));Run
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(&[]));Run
pub fn ends_with(&self, needle: &[T]) -> bool where
T: PartialEq<T>,
1.0.0[src]
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]));Run
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(&[]));Run
pub fn binary_search(&self, x: &T) -> Result<usize, usize> where
T: Ord,
1.0.0[src]
T: Ord,
Binary searches this sorted slice for a given element.
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. 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.
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, });Run
pub fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize> where
F: FnMut(&'a T) -> Ordering,
1.0.0[src]
F: FnMut(&'a T) -> Ordering,
Binary searches this sorted slice with a comparator function.
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. 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.
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, });Run
pub fn binary_search_by_key<'a, B, F>(
&'a self,
b: &B,
f: F
) -> Result<usize, usize> where
B: Ord,
F: FnMut(&'a T) -> B,
1.10.0[src]
&'a self,
b: &B,
f: F
) -> Result<usize, usize> where
B: Ord,
F: FnMut(&'a T) -> B,
Binary searches this sorted 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 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. 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.
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, });Run
pub fn sort_unstable(&mut self) where
T: Ord,
1.20.0[src]
T: Ord,
Sorts the slice, but may 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]);Run
pub fn sort_unstable_by<F>(&mut self, compare: F) where
F: FnMut(&T, &T) -> Ordering,
1.20.0[src]
F: FnMut(&T, &T) -> Ordering,
Sorts the slice with a comparator function, but may 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 or a > b is true; and
- transitive, a < b and b < c implies a < 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_by(|a, b| a.partial_cmp(b).unwrap()); assert_eq!(floats, [1.0, 2.0, 3.0, 4.0, 5.0]);Run
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]);Run
pub fn sort_unstable_by_key<K, F>(&mut self, f: F) where
F: FnMut(&T) -> K,
K: Ord,
1.20.0[src]
F: FnMut(&T) -> K,
K: Ord,
Sorts the slice with a key extraction function, but may 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(m 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]);Run
pub fn partition_at_index(
&mut self,
index: usize
) -> (&mut [T], &mut T, &mut [T]) where
T: Ord,
[src]
&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 values: all elements less
than the one at the given index, the value at the given index, and all elements greater than
the one at the given 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
#![feature(slice_partition_at_index)] let mut v = [-5i32, 4, 1, -3, 2]; // Find the median v.partition_at_index(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]);Run
pub fn partition_at_index_by<F>(
&mut self,
index: usize,
compare: F
) -> (&mut [T], &mut T, &mut [T]) where
F: FnMut(&T, &T) -> Ordering,
[src]
&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
values: all elements less than the one at the given index, the value at the given index,
and all elements greater than the one at the given index, using the provided comparator
function.
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
#![feature(slice_partition_at_index)] let mut v = [-5i32, 4, 1, -3, 2]; // Find the median as if the slice were sorted in descending order. v.partition_at_index_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]);Run
pub fn partition_at_index_by_key<K, F>(
&mut self,
index: usize,
f: F
) -> (&mut [T], &mut T, &mut [T]) where
F: FnMut(&T) -> K,
K: Ord,
[src]
&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
values: all elements less than the one at the given index, the value at the given index, and
all elements greater than the one at the given index, using the provided key extraction
function.
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
#![feature(slice_partition_at_index)] let mut v = [-5i32, 4, 1, -3, 2]; // Return the median as if the array were sorted according to absolute value. v.partition_at_index_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]);Run
pub fn partition_dedup(&mut self) -> (&mut [T], &mut [T]) where
T: PartialEq<T>,
[src]
T: PartialEq<T>,
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]);Run
pub fn partition_dedup_by<F>(&mut self, same_bucket: F) -> (&mut [T], &mut [T]) where
F: FnMut(&mut T, &mut T) -> bool,
[src]
F: FnMut(&mut T, &mut T) -> bool,
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"]);Run
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>,
[src]
F: FnMut(&mut T) -> K,
K: PartialEq<K>,
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]);Run
pub fn rotate_left(&mut self, mid: usize)
1.26.0[src]
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']);Run
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']);Run
pub fn rotate_right(&mut self, k: usize)
1.26.0[src]
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']);Run
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']);Run
pub fn clone_from_slice(&mut self, src: &[T]) where
T: Clone,
1.7.0[src]
T: Clone,
Copies the elements from src
into self
.
The length of src
must be the same as self
.
If src
implements Copy
, it can be more performant to use
copy_from_slice
.
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]);Run
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!Run
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]);Run
pub fn copy_from_slice(&mut self, src: &[T]) where
T: Copy,
1.9.0[src]
T: Copy,
Copies all elements from src
into self
, using a memcpy.
The length of src
must be the same as self
.
If src
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]);Run
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!Run
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]);Run
pub fn copy_within<R>(&mut self, src: R, dest: usize) where
R: RangeBounds<usize>,
T: Copy,
[src]
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!");Run
pub fn swap_with_slice(&mut self, other: &mut [T])
1.27.0[src]
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]);Run
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!Run
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]);Run
pub unsafe fn align_to<U>(&self) -> (&[T], &[U], &[T])
1.30.0[src]
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 does a best effort to 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.
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); }Run
pub unsafe fn align_to_mut<U>(&mut self) -> (&mut [T], &mut [U], &mut [T])
1.30.0[src]
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 does a best effort to 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.
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); }Run
pub fn is_sorted(&self) -> bool where
T: PartialOrd<T>,
[src]
T: PartialOrd<T>,
🔬 This is a nightly-only experimental API. (is_sorted
#53485)
new API
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, std::f32::NAN].is_sorted());Run
pub fn is_sorted_by<F>(&self, compare: F) -> bool where
F: FnMut(&T, &T) -> Option<Ordering>,
[src]
F: FnMut(&T, &T) -> Option<Ordering>,
🔬 This is a nightly-only experimental API. (is_sorted
#53485)
new API
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.
pub fn is_sorted_by_key<F, K>(&self, f: F) -> bool where
F: FnMut(&T) -> K,
K: PartialOrd<K>,
[src]
F: FnMut(&T) -> K,
K: PartialOrd<K>,
🔬 This is a nightly-only experimental API. (is_sorted
#53485)
new API
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()));Run
pub fn is_ascii(&self) -> bool
1.23.0[src]
Checks if all bytes in this slice are within the ASCII range.
pub fn eq_ignore_ascii_case(&self, other: &[u8]) -> bool
1.23.0[src]
Checks that two slices are an ASCII case-insensitive match.
Same as to_ascii_lowercase(a) == to_ascii_lowercase(b)
,
but without allocating and copying temporaries.
pub fn make_ascii_uppercase(&mut self)
1.23.0[src]
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
.
pub fn make_ascii_lowercase(&mut self)
1.23.0[src]
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
.
pub fn sort(&mut self) where
T: Ord,
1.0.0[src]
T: Ord,
Sorts the slice.
This sort is stable (i.e., does not reorder equal elements) and O(n log n)
worst-case.
When applicable, unstable sorting is preferred because it is generally faster than stable
sorting and it doesn't allocate auxiliary memory.
See sort_unstable
.
Current implementation
The current algorithm is an adaptive, iterative merge sort inspired by timsort. It is designed to be very fast in cases where the slice is nearly sorted, or consists of two or more sorted sequences concatenated one after another.
Also, it allocates temporary storage half the size of self
, but for short slices a
non-allocating insertion sort is used instead.
Examples
let mut v = [-5, 4, 1, -3, 2]; v.sort(); assert!(v == [-5, -3, 1, 2, 4]);Run
pub fn sort_by<F>(&mut self, compare: F) where
F: FnMut(&T, &T) -> Ordering,
1.0.0[src]
F: FnMut(&T, &T) -> Ordering,
Sorts the slice with a comparator function.
This sort is stable (i.e., does not reorder equal elements) 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_by(|a, b| a.partial_cmp(b).unwrap()); assert_eq!(floats, [1.0, 2.0, 3.0, 4.0, 5.0]);Run
When applicable, unstable sorting is preferred because it is generally faster than stable
sorting and it doesn't allocate auxiliary memory.
See sort_unstable_by
.
Current implementation
The current algorithm is an adaptive, iterative merge sort inspired by timsort. It is designed to be very fast in cases where the slice is nearly sorted, or consists of two or more sorted sequences concatenated one after another.
Also, it allocates temporary storage half the size of self
, but for short slices a
non-allocating insertion sort is used instead.
Examples
let mut v = [5, 4, 1, 3, 2]; v.sort_by(|a, b| a.cmp(b)); assert!(v == [1, 2, 3, 4, 5]); // reverse sorting v.sort_by(|a, b| b.cmp(a)); assert!(v == [5, 4, 3, 2, 1]);Run
pub fn sort_by_key<K, F>(&mut self, f: F) where
F: FnMut(&T) -> K,
K: Ord,
1.7.0[src]
F: FnMut(&T) -> K,
K: Ord,
Sorts the slice with a key extraction function.
This sort is stable (i.e., does not reorder equal elements) and O(m n log(m n))
worst-case, where the key function is O(m)
.
For expensive key functions (e.g. functions that are not simple property accesses or
basic operations), sort_by_cached_key
is likely to be
significantly faster, as it does not recompute element keys.
When applicable, unstable sorting is preferred because it is generally faster than stable
sorting and it doesn't allocate auxiliary memory.
See sort_unstable_by_key
.
Current implementation
The current algorithm is an adaptive, iterative merge sort inspired by timsort. It is designed to be very fast in cases where the slice is nearly sorted, or consists of two or more sorted sequences concatenated one after another.
Also, it allocates temporary storage half the size of self
, but for short slices a
non-allocating insertion sort is used instead.
Examples
let mut v = [-5i32, 4, 1, -3, 2]; v.sort_by_key(|k| k.abs()); assert!(v == [1, 2, -3, 4, -5]);Run
pub fn sort_by_cached_key<K, F>(&mut self, f: F) where
F: FnMut(&T) -> K,
K: Ord,
1.34.0[src]
F: FnMut(&T) -> K,
K: Ord,
Sorts the slice with a key extraction function.
During sorting, the key function is called only once per element.
This sort is stable (i.e., does not reorder equal elements) and O(m n + n log n)
worst-case, where the key function is O(m)
.
For simple key functions (e.g., functions that are property accesses or
basic operations), sort_by_key
is likely to be
faster.
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.
In the worst case, the algorithm allocates temporary storage in a Vec<(K, usize)>
the
length of the slice.
Examples
let mut v = [-5i32, 4, 32, -3, 2]; v.sort_by_cached_key(|k| k.to_string()); assert!(v == [-3, -5, 2, 32, 4]);Run
pub fn to_vec(&self) -> Vec<T> where
T: Clone,
1.0.0[src]
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.Run
pub fn repeat(&self, n: usize) -> Vec<T> where
T: Copy,
[src]
T: Copy,
🔬 This is a nightly-only experimental API. (repeat_generic_slice
#48784)
it's on str, why not on slice?
Creates a vector by repeating a slice n
times.
Panics
This function will panic if the capacity would overflow.
Examples
Basic usage:
#![feature(repeat_generic_slice)] fn main() { assert_eq!([1, 2].repeat(3), vec![1, 2, 1, 2, 1, 2]); }Run
A panic upon overflow:
#![feature(repeat_generic_slice)] fn main() { // this will panic at runtime b"0123456789abcdef".repeat(usize::max_value()); }Run
pub fn to_ascii_uppercase(&self) -> Vec<u8>
1.23.0[src]
Returns a vector containing a copy of this slice where each byte is mapped to its ASCII upper case equivalent.
ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', but non-ASCII letters are unchanged.
To uppercase the value in-place, use make_ascii_uppercase
.
pub fn to_ascii_lowercase(&self) -> Vec<u8>
1.23.0[src]
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
.
Trait Implementations
impl<'a> Debug for IoSliceMut<'a>
[src]
impl<'a> Deref for IoSliceMut<'a>
[src]
impl<'a> DerefMut for IoSliceMut<'a>
[src]
Auto Trait Implementations
impl<'a> !Send for IoSliceMut<'a>
impl<'a> !Sync for IoSliceMut<'a>
Blanket Implementations
impl<T> From<T> for T
[src]
impl<T, U> TryFrom<U> for T where
U: Into<T>,
[src]
U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
[src]
impl<T, U> Into<U> for T where
U: From<T>,
[src]
U: From<T>,
impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
[src]
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
[src]
impl<T> Borrow<T> for T where
T: ?Sized,
[src]
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
[src]
T: ?Sized,
ⓘImportant traits for &'_ mut Ffn borrow_mut(&mut self) -> &mut T
[src]
impl<T> Any for T where
T: 'static + ?Sized,
[src]
T: 'static + ?Sized,