Struct staticvec::StaticVec [−][src]
pub struct StaticVec<T, const N: usize> { /* fields omitted */ }
Expand description
A Vec
-like struct (mostly directly API-compatible where it can be)
implemented with const generics around an array of fixed N
capacity.
Please note that while rustdoc
does currently correctly render inherent const fn
method
signatures, the same is not true of const
trait implementation method signatures, so at this
time it’s recommended that you refer directly to the source code of this crate if unsure of
whether a given trait has been implemented as const
in conjunction with the const_trait_impl
feature.
Implementations
Returns a new StaticVec instance.
Example usage:
let v = StaticVec::<i32, 4>::new();
assert_eq!(v.len(), 0);
assert_eq!(v.capacity(), 4);
static CV: StaticVec<i32, 4> = StaticVec::new();
static LEN: usize = CV.len();
static CAP: usize = CV.capacity();
assert_eq!(LEN, 0);
assert_eq!(CAP, 4);
Returns a new StaticVec instance filled with the contents, if any, of a slice reference,
which can be either &mut
or &
as if it is &mut
it will implicitly coerce to &
.
If the slice has a length greater than the StaticVec’s declared capacity,
any contents after that point are ignored.
Locally requires that T
implements Copy
to avoid soundness issues.
Example usage:
let v = StaticVec::<i32, 8>::new_from_slice(&[1, 2, 3]);
assert_eq!(v, [1, 2, 3]);
Returns a new StaticVec instance filled with the contents, if any, of an array. If the array has a length greater than the StaticVec’s declared capacity, any contents after that point are ignored.
The N2
parameter does not need to be provided explicitly, and can be inferred from the array
itself.
This function does not leak memory, as any ignored extra elements in the source
array are explicitly dropped with drop_in_place
after it is
first wrapped in an instance of MaybeUninit
to inhibit the
automatic calling of any destructors its contents may have.
Example usage:
// Same input length as the declared capacity:
let v = StaticVec::<i32, 3>::new_from_array([1, 2, 3]);
assert_eq!(v, [1, 2, 3]);
// Truncated to fit the declared capacity:
let v2 = StaticVec::<i32, 3>::new_from_array([1, 2, 3, 4, 5, 6]);
assert_eq!(v2, [1, 2, 3]);
Note that StaticVec also implements From
for both slices and
fixed-size arrays (as well as several other types), which may prove more ergonomic in some
cases as it allows for a greater degree of type inference:
// The StaticVec on the next line is inferred to be of type `StaticVec<&'static str, 4>`.
let v = StaticVec::from(["A", "B", "C", "D"]);
assert_eq!(v, ["A", "B", "C", "D"]);
// You can essentially use [`From`](core::convert::From) in the vast majority of scenarios
// where *either* [`new_from_slice`](crate::StaticVec::new_from_slice) or
// [`new_from_array`](crate::StaticVec::new_from_array) would be accepted by the compiler,
// and expect it to "just work" like the appropriate one of the two on a contextual basis.
// For example, the two "extra" instances of [`Box`](std::boxed::Box) on the next line will
// be correctly dropped just as they would be when calling
// [`new_from_array`](crate::StaticVec::new_from_array).
let v2 = StaticVec::<Box<i32>, 2>::from([box 1, box 2, box 3, box 4]);
assert_eq!(v2, [box 1, box 2]);
A version of new_from_array
specifically designed
for use as a const fn
constructor (although it can of course be used in non-const contexts
as well.)
Being const
necessitates that this function can only accept arrays with a length
exactly equal to the declared capacity of the resulting StaticVec, so if you do need
flexibility with regards to input lengths it’s recommended that you use
new_from_array
or the From
implementations instead.
Note that both forms of the staticvec!
macro are implemented using
new_from_const_array
, so you may also prefer
to use them instead of it directly.
Example usage:
const v: StaticVec<i32, 4> = StaticVec::new_from_const_array([1, 2, 3, 4]);
assert_eq!(v, staticvec![1, 2, 3, 4]);
Returns the current length of the StaticVec. Just as for a normal Vec
,
this means the number of elements that have been added to it with
push
, insert
, etc. except in the
case that it has been set directly with the unsafe set_len
function.
Example usage:
assert_eq!(staticvec![1].len(), 1);
Returns the total capacity of the StaticVec.
This is always equivalent to the generic N
parameter it was declared with, which determines
the fixed size of the backing array.
Example usage:
assert_eq!(StaticVec::<usize, 800>::new().capacity(), 800);
Does the same thing as capacity
, but as an associated function
rather than a method.
Example usage:
assert_eq!(StaticVec::<f64, 12>::cap(), 12)
Serves the same purpose as capacity
, but as an associated
constant rather than a method.
Example usage:
assert_eq!(StaticVec::<f64, 12>::CAPACITY, 12)
Returns the remaining capacity (which is to say, self.capacity() - self.len()
) of the
StaticVec.
Example usage:
let mut vec = StaticVec::<i32, 100>::new();
vec.push(1);
assert_eq!(vec.remaining_capacity(), 99);
Returns the total size of the inhabited part of the StaticVec (which may be zero if it has a
length of zero or contains ZSTs) in bytes. Specifically, the return value of this function
amounts to a calculation of size_of::<T>() * self.len()
.
Example usage:
let x = StaticVec::<u8, 8>::from([1, 2, 3, 4, 5, 6, 7, 8]);
assert_eq!(x.size_in_bytes(), 8);
let y = StaticVec::<u16, 8>::from([1, 2, 3, 4, 5, 6, 7, 8]);
assert_eq!(y.size_in_bytes(), 16);
let z = StaticVec::<u32, 8>::from([1, 2, 3, 4, 5, 6, 7, 8]);
assert_eq!(z.size_in_bytes(), 32);
let w = StaticVec::<u64, 8>::from([1, 2, 3, 4, 5, 6, 7, 8]);
assert_eq!(w.size_in_bytes(), 64);
Directly sets the length field of the StaticVec to new_len
. Useful if you intend
to write to it solely element-wise, but marked unsafe due to how it creates
the potential for reading from uninitialized memory later on.
Safety
It is up to the caller to ensure that new_len
is less than or equal to the StaticVec’s
constant N
parameter, and that the range of elements covered by a length of new_len
is
actually initialized. Failure to do so will almost certainly result in undefined behavior.
Example usage:
let mut vec = StaticVec::<i32, 12>::new();
let data = staticvec![1, 2, 3, 4];
unsafe {
data.as_ptr().copy_to_nonoverlapping(vec.as_mut_ptr(), 4);
vec.set_len(4);
}
assert_eq!(vec.len(), 4);
assert_eq!(vec.remaining_capacity(), 8);
assert_eq!(vec, data);
Returns true if the current length of the StaticVec is 0.
Example usage:
assert!(StaticVec::<i32, 4>::new().is_empty());
Returns true if the current length of the StaticVec is greater than 0.
Example usage:
assert!(staticvec![staticvec![1, 1], staticvec![2, 2]].is_not_empty());
Returns true if the current length of the StaticVec is equal to its capacity.
Example usage:
assert!(StaticVec::<i32, 4>::filled_with(|| 2).is_full());
Returns true if the current length of the StaticVec is less than its capacity.
Example usage:
assert!(StaticVec::<i32, 4>::new().is_not_full());
Returns a constant pointer to the first element of the StaticVec’s internal array. It is up to the caller to ensure that the StaticVec lives for as long as they intend to make use of the returned pointer, as once the StaticVec is dropped the pointer will point to uninitialized or “garbage” memory.
Example usage:
let v = staticvec!['A', 'B', 'C'];
let p = v.as_ptr();
unsafe { assert_eq!(*p, 'A') };
Returns a mutable pointer to the first element of the StaticVec’s internal array. It is up to the caller to ensure that the StaticVec lives for as long as they intend to make use of the returned pointer, as once the StaticVec is dropped the pointer will point to uninitialized or “garbage” memory.
Example usage:
let mut v = staticvec!['A', 'B', 'C'];
let p = v.as_mut_ptr();
unsafe { *p = 'X' };
assert_eq!(v, ['X', 'B', 'C']);
Returns a constant reference to a slice of the StaticVec’s inhabited area.
Example usage:
assert_eq!(staticvec![1, 2, 3].as_slice(), &[1, 2, 3]);
Returns a mutable reference to a slice of the StaticVec’s inhabited area.
Example usage:
let mut v = staticvec![4, 5, 6];
let s = v.as_mut_slice();
s[1] = 9;
assert_eq!(v, [4, 9, 6]);
Returns a constant pointer to the element of the StaticVec at index
without doing any
checking to ensure that index
is actually within any particular bounds. The return value of
this function is equivalent to what would be returned from as_ptr().add(index)
.
Safety
It is up to the caller to ensure that index
is within the appropriate bounds such that the
function returns a pointer to a location that falls somewhere inside the full span of the
StaticVec’s backing array, and that if reading from the returned pointer, it has already
been initialized properly.
Example usage:
let v = staticvec!["I", "am", "a", "StaticVec!"];
unsafe {
let p = v.ptr_at_unchecked(3);
assert_eq!(*p, "StaticVec!");
}
Returns a mutable pointer to the element of the StaticVec at index
without doing any
checking to ensure that index
is actually within any particular bounds. The return value of
this function is equivalent to what would be returned from as_mut_ptr().add(index)
.
Safety
It is up to the caller to ensure that index
is within the appropriate bounds such that the
function returns a pointer to a location that falls somewhere inside the full span of the
StaticVec’s backing array.
It is also the responsibility of the caller to ensure that the length
field of the StaticVec
is adjusted to properly reflect whatever range of elements this function may be used to
initialize, and that if reading from the returned pointer, it has already been initialized
properly.
Example usage:
let mut v = staticvec!["I", "am", "not a", "StaticVec!"];
unsafe {
let p = v.mut_ptr_at_unchecked(2);
*p = "a";
}
assert_eq!(v, ["I", "am", "a", "StaticVec!"]);
Returns a constant pointer to the element of the StaticVec at index
if index
is within the range 0..self.length
, or panics if it is not. The return value of this
function is equivalent to what would be returned from as_ptr().add(index)
.
Example usage:
let v = staticvec!["I", "am", "a", "StaticVec!"];
let p = v.ptr_at(3);
unsafe { assert_eq!(*p, "StaticVec!") };
Returns a mutable pointer to the element of the StaticVec at index
if index
is within the range 0..self.length
, or panics if it is not. The return value of this
function is equivalent to what would be returned from as_mut_ptr().add(index)
.
Example usage:
let mut v = staticvec!["I", "am", "not a", "StaticVec!"];
let p = v.mut_ptr_at(2);
unsafe { *p = "a" };
assert_eq!(v, ["I", "am", "a", "StaticVec!"]);
Returns a constant reference to the element of the StaticVec at index
without doing any
checking to ensure that index
is actually within any particular bounds.
Note that unlike slice::get_unchecked
,
this method only supports accessing individual elements via usize
; it cannot also produce
subslices. To get a subslice without a bounds check, use
self.as_slice().get_unchecked(a..b)
.
Safety
It is up to the caller to ensure that index
is within the range 0..self.length
.
Example usage:
unsafe { assert_eq!(*staticvec![1, 2, 3].get_unchecked(1), 2) };
Returns a mutable reference to the element of the StaticVec at index
without doing any
checking to ensure that index
is actually within any particular bounds.
The same differences between this method and the slice method of the same name
apply as do for get_unchecked
.
Safety
It is up to the caller to ensure that index
is within the range 0..self.length
.
Example usage:
let mut v = staticvec![1, 2, 3];
let p = unsafe { v.get_unchecked_mut(1) };
*p = 9;
assert_eq!(v, [1, 9, 3]);
Appends a value to the end of the StaticVec without asserting that
its current length is less than N
.
Safety
It is up to the caller to ensure that the length of the StaticVec
prior to using this function is less than N
. Failure to do so will result
in writing to an out-of-bounds memory region.
Example usage:
let mut v = StaticVec::<i32, 4>::from([1, 2]);
unsafe { v.push_unchecked(3) };
assert_eq!(v, [1, 2, 3]);
Pops a value from the end of the StaticVec and returns it directly without asserting that the StaticVec’s current length is greater than 0.
Safety
It is up to the caller to ensure that the StaticVec contains at least one element prior to using this function. Failure to do so will result in reading from uninitialized memory.
Example usage:
let mut v = StaticVec::<i32, 4>::from([1, 2, 3, 4]);
unsafe { v.pop_unchecked() };
assert_eq!(v, [1, 2, 3]);
Pushes value
to the StaticVec if its current length is less than its capacity,
or returns a PushCapacityError
otherwise.
Example usage:
let mut v1 = StaticVec::<usize, 128>::filled_with_by_index(|i| i * 4);
assert!(v1.try_push(999).is_err());
let mut v2 = StaticVec::<usize, 128>::new();
assert!(v2.try_push(1).is_ok());
Pushes a value to the end of the StaticVec. Panics if the collection is
full; that is, if self.len() == self.capacity()
.
Example usage:
let mut v = StaticVec::<i32, 8>::new();
v.push(1);
v.push(2);
assert_eq!(v, [1, 2]);
Removes the value at the last position of the StaticVec and returns it in Some
if
the StaticVec has a current length greater than 0, and returns None
otherwise.
Example usage:
let mut v = staticvec![1, 2, 3, 4];
assert_eq!(v.pop(), Some(4));
assert_eq!(v.pop(), Some(3));
assert_eq!(v, [1, 2]);
Returns a constant reference to the first element of the StaticVec in Some
if the StaticVec
is not empty, or None
otherwise.
Example usage:
let v1 = staticvec![10, 40, 30];
assert_eq!(Some(&10), v1.first());
let v2 = StaticVec::<i32, 0>::new();
assert_eq!(None, v2.first());
Returns a mutable reference to the first element of the StaticVec in Some
if the StaticVec
is not empty, or None
otherwise.
Example usage:
let mut x = staticvec![0, 1, 2];
if let Some(first) = x.first_mut() {
*first = 5;
}
assert_eq!(x, &[5, 1, 2]);
Returns a constant reference to the last element of the StaticVec in Some
if the StaticVec
is not empty, or None
otherwise.
Example usage:
let v = staticvec![10, 40, 30];
assert_eq!(Some(&30), v.last());
let w = StaticVec::<i32, 0>::new();
assert_eq!(None, w.last());
Returns a mutable reference to the last element of the StaticVec in Some
if the StaticVec is
not empty, or None
otherwise.
Example usage:
let mut x = staticvec![0, 1, 2];
if let Some(last) = x.last_mut() {
*last = 10;
}
assert_eq!(x, &[0, 1, 10]);
Asserts that index
is less than the current length of the StaticVec,
and if so removes the value at that position and returns it. Any values
that exist in later positions are shifted to the left.
Example usage:
assert_eq!(staticvec![1, 2, 3].remove(1), 2);
Removes the first instance of item
from the StaticVec if the item exists.
Example usage:
assert_eq!(staticvec![1, 2, 2, 3].remove_item(&2), Some(2));
Returns None
if index
is greater than or equal to the current length of the StaticVec.
Otherwise, removes the value at that position and returns it in Some
, and then
moves the last value in the StaticVec into the empty slot.
Example usage:
let mut v = staticvec!["AAA", "BBB", "CCC", "DDD"];
assert_eq!(v.swap_pop(1).unwrap(), "BBB");
assert_eq!(v, ["AAA", "DDD", "CCC"]);
Asserts that index
is less than the current length of the StaticVec,
and if so removes the value at that position and returns it, and then
moves the last value in the StaticVec into the empty slot.
Example usage:
let mut v = staticvec!["AAA", "BBB", "CCC", "DDD"];
assert_eq!(v.swap_remove(1), "BBB");
assert_eq!(v, ["AAA", "DDD", "CCC"]);
Asserts that the current length of the StaticVec is less than N
and that
index
is less than the length, and if so inserts value
at that position.
Any values that exist in positions after index
are shifted to the right.
Example usage:
let mut v = StaticVec::<i32, 5>::from([1, 2, 3]);
v.insert(1, 4);
assert_eq!(v, [1, 4, 2, 3]);
pub fn insert_many<I: IntoIterator<Item = T>>(&mut self, index: usize, iter: I) where
I::IntoIter: ExactSizeIterator<Item = T>,
pub fn insert_many<I: IntoIterator<Item = T>>(&mut self, index: usize, iter: I) where
I::IntoIter: ExactSizeIterator<Item = T>,
Functionally equivalent to insert
, except with multiple
items provided by an iterator as opposed to just one. This function will panic up-front if
index
is out of bounds or if the StaticVec does not have a sufficient amount of remaining
capacity, but once the iteration has started will just return immediately if / when the
StaticVec reaches maximum capacity, regardless of whether the iterator still has more items
to yield.
For safety reasons, as StaticVec cannot increase in capacity, the
iterator is required to implement ExactSizeIterator
rather than just Iterator
(though this function still does
the appropriate checking internally to avoid dangerous outcomes in the event of a blatantly
incorrect ExactSizeIterator
implementation.)
Example usage:
let mut v = StaticVec::<usize, 8>::from([1, 2, 3, 4, 7, 8]);
v.insert_many(4, staticvec![5, 6].into_iter());
assert_eq!(v, [1, 2, 3, 4, 5, 6, 7, 8]);
Functionally equivalent to insert_many
, except with
multiple items provided by a slice reference as opposed to an arbitrary iterator. Locally
requires that T
implements Copy
to avoid soundness issues.
Example usage:
let mut v = StaticVec::<usize, 8>::from([1, 2, 3, 4, 7, 8]);
v.insert_from_slice(4, &[5, 6]);
assert_eq!(v, [1, 2, 3, 4, 5, 6, 7, 8]);
Inserts value
at index
if the current length of the StaticVec is less than N
and index
is less than the length, or returns a CapacityError
otherwise. Any values that exist in positions after index
are shifted to the right.
Example usage:
let mut vec = StaticVec::<i32, 5>::from([1, 2, 3, 4, 5]);
assert_eq!(vec.try_insert(2, 0), Err(CapacityError::<5> {}));
pub const fn try_insert_from_slice(
&mut self,
index: usize,
values: &[T]
) -> Result<(), CapacityError<N>> where
T: Copy,
pub const fn try_insert_from_slice(
&mut self,
index: usize,
values: &[T]
) -> Result<(), CapacityError<N>> where
T: Copy,
Does the same thing as insert_from_slice
, but returns
a CapacityError
in the event that something goes wrong as
opposed to relying on internal assertions.
Example usage:
let mut v1 = StaticVec::<usize, 8>::from([1, 2, 3, 4, 7, 8]);
assert!(v1.try_insert_from_slice(4, &[5, 6]).is_ok());
assert_eq!(v1, [1, 2, 3, 4, 5, 6, 7, 8]);
let mut v2 = StaticVec::<usize, 8>::from([1, 2, 3, 4, 7, 8]);
assert!(v2.try_insert_from_slice(207, &[5, 6]).is_err());
Returns true
if value
is present in the StaticVec.
Locally requires that T
implements PartialEq
to make it possible to compare the elements of the StaticVec with value
.
Example usage:
assert_eq!(staticvec![1, 2, 3].contains(&2), true);
assert_eq!(staticvec![1, 2, 3].contains(&4), false);
Removes all contents from the StaticVec and sets its length back to 0.
Example usage:
let mut v = staticvec![1, 2, 3];
assert_eq!(v.len(), 3);
assert_eq!(v, [1, 2, 3]);
v.clear();
assert_eq!(v.len(), 0);
assert_eq!(v, []);
pub const fn iter(&self) -> StaticVecIterConst<'_, T, N>ⓘNotable traits for StaticVecIterConst<'a, T, N>impl<'a, T: 'a, const N: usize> Iterator for StaticVecIterConst<'a, T, N> type Item = &'a T;
pub const fn iter(&self) -> StaticVecIterConst<'_, T, N>ⓘNotable traits for StaticVecIterConst<'a, T, N>impl<'a, T: 'a, const N: usize> Iterator for StaticVecIterConst<'a, T, N> type Item = &'a T;
impl<'a, T: 'a, const N: usize> Iterator for StaticVecIterConst<'a, T, N> type Item = &'a T;
Returns a StaticVecIterConst
over the StaticVec’s
inhabited area.
Example usage:
let v = staticvec![4, 3, 2, 1];
for i in v.iter() {
println!("{}", i);
}
pub const fn iter_mut(&mut self) -> StaticVecIterMut<'_, T, N>ⓘNotable traits for StaticVecIterMut<'a, T, N>impl<'a, T: 'a, const N: usize> Iterator for StaticVecIterMut<'a, T, N> type Item = &'a mut T;
pub const fn iter_mut(&mut self) -> StaticVecIterMut<'_, T, N>ⓘNotable traits for StaticVecIterMut<'a, T, N>impl<'a, T: 'a, const N: usize> Iterator for StaticVecIterMut<'a, T, N> type Item = &'a mut T;
impl<'a, T: 'a, const N: usize> Iterator for StaticVecIterMut<'a, T, N> type Item = &'a mut T;
Returns a StaticVecIterMut
over the StaticVec’s
inhabited area.
Example usage:
let mut v = staticvec![4, 3, 2, 1];
for i in v.iter_mut() {
*i -= 1;
}
assert_eq!(v, [3, 2, 1, 0]);
This is supported on crate feature std
only.
std
only.Returns a separate, stable-sorted StaticVec of the contents of the StaticVec’s inhabited area
without modifying the original data. Locally requires that T
implements
Copy
to avoid soundness issues, and Ord
to make
the sorting possible.
Example usage:
const V: StaticVec<StaticVec<i32, 2>, 2> = staticvec![staticvec![1, 3], staticvec![4, 2]];
assert_eq!(
V.iter().flatten().collect::<StaticVec<i32, 4>>().sorted(),
[1, 2, 3, 4]
);
Returns a separate, unstable-sorted StaticVec of the contents of the StaticVec’s inhabited
area without modifying the original data. Locally requires that T
implements
Copy
to avoid soundness issues, and Ord
to make
the sorting possible.
Example usage:
const V: StaticVec<StaticVec<i32, 2>, 2> = staticvec![staticvec![1, 3], staticvec![4, 2]];
assert_eq!(
V.iter().flatten().collect::<StaticVec<i32, 4>>().sorted_unstable(),
[1, 2, 3, 4]
);
Returns a separate, unstable-quicksorted StaticVec of the contents of the StaticVec’s
inhabited area without modifying the original data. Locally requires that T
implements
Copy
to avoid soundness issues, and
PartialOrd
to make the sorting possible.
Unlike sorted
and
sorted_unstable
, this function does not make use of
Rust’s built-in sorting methods, but instead makes direct use of a comparatively
unsophisticated recursive quicksort algorithm implemented in this crate.
This has the advantage of only needing to have PartialOrd
as a
constraint as opposed to Ord
, but is very likely less performant for
most inputs, so if the type you’re sorting does derive or implement
Ord
it’s recommended that you use sorted
or
sorted_unstable
instead of this function.
Example usage:
const V: StaticVec<StaticVec<i32, 2>, 2> = staticvec![staticvec![1, 3], staticvec![4, 2]];
assert_eq!(
V.iter().flatten().collect::<StaticVec<i32, 4>>().quicksorted_unstable(),
[1, 2, 3, 4]
);
Provides the same sorting functionality as
quicksorted_unstable
(and has the same trait
bound requirements) but operates in-place on the calling StaticVec instance rather than
returning the sorted data in a new one.
Example usage:
let mut v = staticvec![5.0, 4.0, 3.0, 2.0, 1.0];
v.quicksort_unstable();
assert_eq!(v, [1.0, 2.0, 3.0, 4.0, 5.0]);
// Note that if you are actually sorting floating-point numbers as shown above, and the
// StaticVec contains one or more instances of NAN, the "accuracy" of the sorting will
// essentially be determined by a combination of how many *consecutive* NANs there are,
// as well as how "mixed up" the surrounding valid numbers were to begin with. In any case,
// the outcome of this particular hypothetical scenario will never be any worse than the
// values simply not being sorted quite as you'd hoped.
Returns a separate, reversed StaticVec of the contents of the StaticVec’s inhabited area
without modifying the original data. Locally requires that T
implements
Copy
to avoid soundness issues.
Example usage:
assert_eq!(staticvec![1, 2, 3].reversed(), [3, 2, 1]);
Returns a new StaticVec instance filled with the return value of an initializer function. The length field of the newly created StaticVec will be equal to its capacity.
Example usage:
let mut i = 0;
let v = StaticVec::<i32, 64>::filled_with(|| { i += 1; i });
assert_eq!(v.len(), 64);
assert_eq!(v[0], 1);
assert_eq!(v[1], 2);
assert_eq!(v[2], 3);
assert_eq!(v[3], 4);
Returns a new StaticVec instance filled with the return value of an initializer function.
Unlike for filled_with
, the initializer function in
this case must take a single usize variable as an input parameter, which will be called
with the current index of the 0..N
loop that
filled_with_by_index
is implemented with
internally. The length field of the newly created StaticVec will be equal to its capacity.
Example usage:
let v = StaticVec::<usize, 64>::filled_with_by_index(|i| { i + 1 });
assert_eq!(v.len(), 64);
assert_eq!(v[0], 1);
assert_eq!(v[1], 2);
assert_eq!(v[2], 3);
assert_eq!(v[3], 4);
Copies and appends all elements, if any, of a slice (which can also be &mut
as it will
coerce implicitly to &
) to the StaticVec. If the slice has a length greater than the
StaticVec’s remaining capacity, any contents after that point are ignored.
Locally requires that T
implements Copy
to avoid soundness issues.
Example usage:
let mut v = StaticVec::<i32, 8>::new();
v.extend_from_slice(&[1, 2, 3, 4]);
v.extend_from_slice(&[5, 6, 7, 8, 9, 10, 11]);
assert_eq!(v, [1, 2, 3, 4, 5, 6, 7, 8]);
pub fn try_extend_from_slice(
&mut self,
values: &[T]
) -> Result<(), CapacityError<N>> where
T: Copy,
pub fn try_extend_from_slice(
&mut self,
values: &[T]
) -> Result<(), CapacityError<N>> where
T: Copy,
Copies and appends all elements, if any, of a slice to the StaticVec if the
StaticVec’s remaining capacity is greater than the length of the slice, or returns
a CapacityError
otherwise.
Example usage:
let mut v = StaticVec::<i32, 8>::new();
assert!(v.try_extend_from_slice(&[1, 2, 3, 4]).is_ok());
assert!(v.try_extend_from_slice(&[5, 6, 7, 8, 9, 10, 11]).is_err());
assert_eq!(v, [1, 2, 3, 4]);
Appends self.remaining_capacity()
(or as many as available) items from
other
to self
. The appended items (if any) will no longer exist in other
afterwards,
as other
’s length
field will be adjusted to indicate.
The N2
parameter does not need to be provided explicitly, and can be inferred directly from
the constant N2
constraint of other
(which may or may not be the same as the N
constraint of self
.)
Example usage:
let mut a = StaticVec::<i32, 8>::from([1, 2, 3, 4]);
let mut b = staticvec![1, 2, 3, 4, 5, 6, 7, 8];
a.append(&mut b);
assert_eq!(a.len(), 8);
assert_eq!(a, [1, 2, 3, 4, 1, 2, 3, 4]);
assert_eq!(b, [5, 6, 7, 8]);
Returns a new StaticVec consisting of the elements of self
and other
concatenated in
linear fashion such that the first element of other
comes immediately after the last
element of self
.
The N2
parameter does not need to be provided explicitly, and can be inferred directly from
the constant N2
constraint of other
(which may or may not be the same as the N
constraint of self
.)
Locally requires that T
implements Copy
to
avoid soundness issues and also allow for a more efficient implementation than would otherwise
be possible.
Example usage:
assert!(staticvec!['a', 'b'].concat(&staticvec!['c', 'd']) == ['a', 'b', 'c', 'd']);
A version of concat
for scenarios where T
does not
derive Copy
but does implement Clone
.
Due to needing to call clone()
through each individual element of self
and other
, this
function is less efficient than concat
, so
concat
should be preferred whenever possible.
Example usage:
assert!(staticvec!["a", "b"].concat_clone(&staticvec!["c", "d"]) == ["a", "b", "c", "d"]);
Returns a new StaticVec consisting of the elements of self
in linear order, interspersed
with a copy of separator
between each one.
Locally requires that T
implements Copy
to
avoid soundness issues and also allow for a more efficient implementation than would otherwise
be possible.
Example usage:
assert_eq!(
staticvec!["A", "B", "C", "D"].intersperse("Z"),
["A", "Z", "B", "Z", "C", "Z", "D"]
);
A version of intersperse
for scenarios where T
does not
derive Copy
but does implement Clone
.
Due to needing to call clone()
through each individual element of self
and also on
separator
, this function is less efficient than
intersperse
, so
intersperse
should be preferred whenever possible.
Example usage:
assert_eq!(
staticvec!["A", "B", "C", "D"].intersperse_clone("Z"),
["A", "Z", "B", "Z", "C", "Z", "D"]
);
This is supported on crate feature std
only.
std
only.Returns a StaticVec containing the contents of a Vec
instance.
If the Vec
has a length greater than the declared capacity of the
resulting StaticVec, any contents after that point are ignored. Note that using this function
consumes the source Vec
.
Example usage:
let mut v = vec![1, 2, 3];
let sv: StaticVec<i32, 3> = StaticVec::from_vec(v);
assert_eq!(sv, [1, 2, 3]);
This is supported on crate feature std
only.
std
only.Returns a Vec
containing the contents of the StaticVec instance.
The returned Vec
will initially have the same value for
len
and capacity
as the source
StaticVec. Note that using this function consumes the source StaticVec.
Example usage:
let mut sv = staticvec![1, 2, 3];
let v = sv.into_vec();
assert_eq!(v, [1, 2, 3]);
Inspired by the function of the same name from ArrayVec
, this function directly returns
the StaticVec’s backing array (as a “normal” array not wrapped in an instance of
MaybeUninit
) in Ok
if and only if the StaticVec is at maximum capacity. Otherwise, the
StaticVec itself is returned in Err
.
Example usage:
let mut v1 = StaticVec::<i32, 4>::new();
v1.push(1);
v1.push(2);
let a = v1.into_inner();
assert!(a.is_err());
let v2 = staticvec![1, 2, 3, 4];
let a = v2.into_inner();
assert!(a.is_ok());
assert_eq!(a.unwrap(), [1, 2, 3, 4]);
Removes the specified range of elements from the StaticVec and returns them in a new one.
Panics
Panics if the range’s starting point is greater than the end point or if the end point is greater than the length of the StaticVec.
Example usage:
let mut v = staticvec![1, 2, 3];
let u = v.drain(1..);
assert_eq!(v, &[1]);
pub fn drain_iter<R: RangeBounds<usize>>(
&mut self,
range: R
) -> StaticVecDrain<'_, T, N>ⓘNotable traits for StaticVecDrain<'a, T, N>impl<'a, T: 'a, const N: usize> Iterator for StaticVecDrain<'a, T, N> type Item = T;
pub fn drain_iter<R: RangeBounds<usize>>(
&mut self,
range: R
) -> StaticVecDrain<'_, T, N>ⓘNotable traits for StaticVecDrain<'a, T, N>impl<'a, T: 'a, const N: usize> Iterator for StaticVecDrain<'a, T, N> type Item = T;
impl<'a, T: 'a, const N: usize> Iterator for StaticVecDrain<'a, T, N> type Item = T;
Removes the specified range of elements from the StaticVec and returns them in a
StaticVecDrain
.
Panics
Panics if the range’s starting point is greater than the end point or if the end point is greater than the length of the StaticVec.
Example usage:
let mut v1 = staticvec![0, 4, 5, 6, 7];
let v2: StaticVec<i32, 3> = v1.drain_iter(1..4).rev().collect();
assert_eq!(v2, [6, 5, 4]);
Removes all elements in the StaticVec for which filter
returns true and returns them in a
new one.
Example usage:
let mut numbers = staticvec![1, 2, 3, 4, 5, 6, 8, 9, 11, 13, 14, 15];
let evens = numbers.drain_filter(|x| *x % 2 == 0);
let odds = numbers;
assert_eq!(evens, [2, 4, 6, 8, 14]);
assert_eq!(odds, [1, 3, 5, 9, 11, 13, 15]);
pub fn splice<R: RangeBounds<usize>, I: IntoIterator<Item = T>>(
&mut self,
range: R,
replace_with: I
) -> StaticVecSplice<T, I::IntoIter, N>ⓘNotable traits for StaticVecSplice<T, I, N>impl<T, I: Iterator<Item = T>, const N: usize> Iterator for StaticVecSplice<T, I, N> type Item = T;
pub fn splice<R: RangeBounds<usize>, I: IntoIterator<Item = T>>(
&mut self,
range: R,
replace_with: I
) -> StaticVecSplice<T, I::IntoIter, N>ⓘNotable traits for StaticVecSplice<T, I, N>impl<T, I: Iterator<Item = T>, const N: usize> Iterator for StaticVecSplice<T, I, N> type Item = T;
impl<T, I: Iterator<Item = T>, const N: usize> Iterator for StaticVecSplice<T, I, N> type Item = T;
Replaces the specified range in the StaticVec with the contents of replace_with
and returns
the removed items in an instance of StaticVecSplice
.
replace_with
does not need to be the same length as range
. Returns immediately if and when
the StaticVec reaches maximum capacity, regardless of whether or not replace_with
still has
more items to yield.
Panics
Panics if the range’s starting point is greater than the end point or if the end point is greater than the length of the StaticVec.
Example usage:
let mut v = staticvec![1, 2, 3];
let new = [7, 8];
let u: StaticVec<u8, 2> = v.splice(..2, new.iter().copied()).collect();
assert_eq!(v, [7, 8, 3]);
assert_eq!(u, [1, 2]);
Removes all elements in the StaticVec for which filter
returns false.
Example usage:
let mut v = staticvec![1, 2, 3, 4, 5];
let keep = staticvec![false, true, true, false, true];
let mut i = 0;
v.retain(|_| (keep[i], i += 1).0);
assert_eq!(v, [2, 3, 5]);
Shortens the StaticVec, keeping the first length
elements and dropping the rest.
Does nothing if length
is greater than or equal to the current length of the StaticVec.
Example usage:
let mut v = staticvec![1, 2, 3, 4, 5];
v.truncate(2);
assert_eq!(v, [1, 2]);
Splits one StaticVec into two at the given index, returning the second half without consuming
the first half. The original StaticVec will contain all elements within the exclusive range
0..at
, and the new one will contain all elements within the exclusive range
at..self.len()
. This function will panic if at
is greater than self.len()
.
Example usage:
let mut v1 = staticvec![1, 2, 3];
let v2 = v1.split_off(1);
assert_eq!(v1, [1]);
assert_eq!(v2, [2, 3]);
Splits one StaticVec into two new ones at index M
and returns them in a tuple, while
consuming the original. The first new one will contain all elements within the exclusive range
0..M
, and the second new one will contain all elements within the exclusive range
M..self.len()
. This function will panic if M
is greater than self.len()
.
Example usage:
let v1 = staticvec![box 1, box 2, box 3, box 4, box 5, box 6];
let t1 = v1.split_at::<0>();
assert_eq!(t1.0, []);
assert_eq!(t1.1, [box 1, box 2, box 3, box 4, box 5, box 6]);
let v2 = staticvec![box 1, box 2, box 3, box 4, box 5, box 6];
let t2 = v2.split_at::<2>();
assert_eq!(t2.0, [box 1, box 2]);
assert_eq!(t2.1, [box 3, box 4, box 5, box 6]);
let v3 = staticvec![box 1, box 2, box 3, box 4, box 5, box 6];
let t3 = v3.split_at::<6>();
assert_eq!(t3.0, [box 1, box 2, box 3, box 4, box 5, box 6]);
assert_eq!(t3.1, []);
Removes all but the first of consecutive elements in the StaticVec satisfying a given equality relation.
Example usage:
let mut v = staticvec!["aaa", "bbb", "BBB", "ccc", "ddd"];
v.dedup_by(|a, b| a.eq_ignore_ascii_case(b));
assert_eq!(v, ["aaa", "bbb", "ccc", "ddd"]);
Removes consecutive repeated elements in the StaticVec according to the
locally required PartialEq
trait implementation for T
.
Example usage:
let mut v = staticvec![1, 2, 2, 3, 2];
v.dedup();
assert_eq!(v, [1, 2, 3, 2]);
Removes all but the first of consecutive elements in the StaticVec that resolve to the same key.
Example usage:
let mut v = staticvec![10, 20, 21, 30, 20];
v.dedup_by_key(|i| *i / 10);
assert_eq!(v, [10, 20, 30, 20]);
Returns a new StaticVec representing the difference of self
and other
(that is,
all items present in self
, but not present in other
.)
The N2
parameter does not need to be provided explicitly, and can be inferred from other
itself.
Locally requires that T
implements Clone
to avoid soundness issues
while accommodating for more types than Copy
would appropriately for
this function, and PartialEq
to make the item comparisons possible.
Example usage:
assert_eq!(
staticvec![4, 5, 6, 7].difference(&staticvec![1, 2, 3, 7]),
[4, 5, 6]
);
Returns a new StaticVec representing the symmetric difference of self
and other
(that is,
all items present in at least one of self
or other
, but not present in both.)
The N2
parameter does not need to be provided explicitly, and can be inferred from other
itself.
Locally requires that T
implements Clone
to avoid soundness issues
while accommodating for more types than Copy
would appropriately for
this function, and PartialEq
to make the item comparisons possible.
Example usage:
assert_eq!(
staticvec![1, 2, 3].symmetric_difference(&staticvec![3, 4, 5]),
[1, 2, 4, 5]
);
Returns a new StaticVec representing the intersection of self
and other
(that is,
all items present in both self
and other
.)
The N2
parameter does not need to be provided explicitly, and can be inferred from other
itself.
Locally requires that T
implements Clone
to avoid soundness issues
while accommodating for more types than Copy
would appropriately for
this function, and PartialEq
to make the item comparisons possible.
Example usage:
assert_eq!(
staticvec![4, 5, 6, 7].intersection(&staticvec![1, 2, 3, 7, 4]),
[4, 7],
);
Returns a new StaticVec representing the union of self
and other
(that is, the full
contents of both self
and other
, minus any duplicates.)
The N2
parameter does not need to be provided explicitly, and can be inferred from other
itself.
Locally requires that T
implements Clone
to avoid soundness issues
while accommodating for more types than Copy
would appropriately for
this function, and PartialEq
to make the item comparisons possible.
Example usage:
assert_eq!(
staticvec![1, 2, 3].union(&staticvec![4, 2, 3, 4]),
[1, 2, 3, 4],
);
A concept borrowed from the widely-used SmallVec
crate, this function
returns a tuple consisting of a constant pointer to the first element of the StaticVec,
the length of the StaticVec, and the capacity of the StaticVec.
Example usage:
static V: StaticVec<usize, 4> = staticvec![4, 5, 6, 7];
assert_eq!(V.triple(), (V.as_ptr(), 4, 4));
A mutable version of triple
. This implementation differs from
the one found in SmallVec
in that it only provides the first element of the StaticVec as
a mutable pointer, not also the length as a mutable reference.
Example:
let mut v = staticvec![4, 5, 6, 7];
let t = v.triple_mut();
assert_eq!(t, (v.as_mut_ptr(), 4, 4));
unsafe { *t.0 = 8 };
assert_eq!(v, [8, 5, 6, 7]);
Linearly adds (in a mathematical sense) the contents of two same-capacity StaticVecs and returns the results in a new one of equal capacity.
Locally requires that T
implements Copy
to allow
for an efficient implementation, and Add
to make it possible
to add the elements.
For both performance and safety reasons, this function requires that both self
and other
are at full capacity, and will panic if that is not the case (that is,
if self.is_full() && other.is_full()
is not equal to true
.)
Example usage:
const A: StaticVec<f64, 4> = staticvec![4.0, 5.0, 6.0, 7.0];
const B: StaticVec<f64, 4> = staticvec![2.0, 3.0, 4.0, 5.0];
assert_eq!(A.added(&B), [6.0, 8.0, 10.0, 12.0]);
Linearly subtracts (in a mathematical sense) the contents of two same-capacity StaticVecs and returns the results in a new one of equal capacity.
Locally requires that T
implements Copy
to allow
for an efficient implementation, and Sub
to make it possible
to subtract the elements.
For both performance and safety reasons, this function requires that both self
and other
are at full capacity, and will panic if that is not the case (that is,
if self.is_full() && other.is_full()
is not equal to true
.)
Example usage:
const A: StaticVec<f64, 4> = staticvec![4.0, 5.0, 6.0, 7.0];
const B: StaticVec<f64, 4> = staticvec![2.0, 3.0, 4.0, 5.0];
assert_eq!(A.subtracted(&B), [2.0, 2.0, 2.0, 2.0]);
Linearly multiplies (in a mathematical sense) the contents of two same-capacity StaticVecs and returns the results in a new one of equal capacity.
Locally requires that T
implements Copy
to allow
for an efficient implementation, and Mul
to make it possible
to multiply the elements.
For both performance and safety reasons, this function requires that both self
and other
are at full capacity, and will panic if that is not the case (that is,
if self.is_full() && other.is_full()
is not equal to true
.)
Example usage:
const A: StaticVec<f64, 4> = staticvec![4.0, 5.0, 6.0, 7.0];
const B: StaticVec<f64, 4> = staticvec![2.0, 3.0, 4.0, 5.0];
assert_eq!(A.multiplied(&B), [8.0, 15.0, 24.0, 35.0]);
Linearly divides (in a mathematical sense) the contents of two same-capacity StaticVecs and returns the results in a new one of equal capacity.
Locally requires that T
implements Copy
to allow
for an efficient implementation, and Div
to make it possible
to divide the elements.
For both performance and safety reasons, this function requires that both self
and other
are at full capacity, and will panic if that is not the case (that is,
if self.is_full() && other.is_full()
is not equal to true
.)
Example usage:
const A: StaticVec<f64, 4> = staticvec![4.0, 5.0, 6.0, 7.0];
const B: StaticVec<f64, 4> = staticvec![2.0, 3.0, 4.0, 5.0];
assert_eq!(A.divided(&B), [2.0, 1.6666666666666667, 1.5, 1.4]);
Methods from Deref<Target = [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());
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]);
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]);
}
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]);
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]);
}
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]);
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());
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[src]pub 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[src]pub 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[src]pub unsafe fn get_unchecked<I>(
&self,
index: I
) -> &<I as SliceIndex<[T]>>::Output where
I: SliceIndex<[T]>,
pub unsafe fn get_unchecked<I>(
&self,
index: I
) -> &<I as SliceIndex<[T]>>::Output where
I: SliceIndex<[T]>,
Returns a reference to an element or subslice, without doing bounds checking.
For a safe alternative see get
.
Safety
Calling this method with an out-of-bounds index is undefined behavior even if the resulting reference is not used.
Examples
let x = &[1, 2, 4];
unsafe {
assert_eq!(x.get_unchecked(1), &2);
}
1.0.0[src]pub unsafe fn get_unchecked_mut<I>(
&mut self,
index: I
) -> &mut <I as SliceIndex<[T]>>::Output where
I: SliceIndex<[T]>,
pub unsafe fn get_unchecked_mut<I>(
&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.
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]);
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));
}
}
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]);
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));
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++.
🔬 This is a nightly-only experimental API. (slice_swap_unchecked
)
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"]);
Reverses the order of elements in the slice, in place.
Examples
let mut v = [1, 2, 3];
v.reverse();
assert!(v == [3, 2, 1]);
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);
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]);
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());
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());
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]);
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']);
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]);
🔬 This is a nightly-only experimental API. (slice_as_chunks
)
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
🔬 This is a nightly-only experimental API. (slice_as_chunks
)
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']);
🔬 This is a nightly-only experimental API. (slice_as_chunks
)
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']]);
🔬 This is a nightly-only experimental API. (array_chunks
)
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']);
🔬 This is a nightly-only experimental API. (slice_as_chunks
)
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
🔬 This is a nightly-only experimental API. (slice_as_chunks
)
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]);
🔬 This is a nightly-only experimental API. (slice_as_chunks
)
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]);
🔬 This is a nightly-only experimental API. (array_chunks
)
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]);
🔬 This is a nightly-only experimental API. (array_windows
)
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());
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());
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]);
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']);
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]);
🔬 This is a nightly-only experimental API. (slice_group_by
)
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);
pub 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);
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, []);
}
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]);
🔬 This is a nightly-only experimental API. (slice_split_at_unchecked
)
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, []);
}
🔬 This is a nightly-only experimental API. (slice_split_at_unchecked
)
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]);
🔬 This is a nightly-only experimental API. (split_array
)
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, []);
}
🔬 This is a nightly-only experimental API. (split_array
)
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]);
🔬 This is a nightly-only experimental API. (split_array
)
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]);
}
🔬 This is a nightly-only experimental API. (split_array
)
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]);
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());
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[src]pub 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[src]pub 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]);
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);
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]);
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);
}
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]);
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[src]pub 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]);
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));
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"));
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(&[]));
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[src]pub 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[src]pub 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);
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. 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 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.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]);
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. 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, });
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. 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, });
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]);
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]);
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]);
👎 Deprecated since 1.49.0: use the select_nth_unstable() instead
🔬 This is a nightly-only experimental API. (slice_partition_at_index
)
use the select_nth_unstable() instead
slice_partition_at_index
)Reorder the slice such that the element at index
is at its final sorted position.
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,
👎 Deprecated since 1.49.0: use select_nth_unstable_by() instead
🔬 This is a nightly-only experimental API. (slice_partition_at_index
)
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,
use select_nth_unstable_by() instead
slice_partition_at_index
)Reorder the slice with a comparator function such that the element at index
is at its
final sorted position.
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,
👎 Deprecated since 1.49.0: use the select_nth_unstable_by_key() instead
🔬 This is a nightly-only experimental API. (slice_partition_at_index
)
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,
use the select_nth_unstable_by_key() instead
slice_partition_at_index
)Reorder the slice with a key extraction function such that the element at index
is at its
final sorted position.
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
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]);
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
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]);
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
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]);
🔬 This is a nightly-only experimental API. (slice_partition_dedup
)
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]);
pub 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"]);
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>,
🔬 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]);
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']);
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']);
Fills self
with elements by cloning value
.
Examples
let mut buf = vec![0; 10];
buf.fill(1);
assert_eq!(buf, vec![1; 10]);
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]);
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]);
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[src]pub 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!");
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]);
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);
}
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);
}
pub fn as_simd<const LANES: usize>(&self) -> (&[T], &[Simd<T, LANES>], &[T]) where
T: SimdElement,
Simd<T, LANES>: AsRef<[T; LANES]>,
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
T: SimdElement,
Simd<T, LANES>: AsRef<[T; LANES]>,
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)]
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.horizontal_sum()
}
let numbers: Vec<f32> = (1..101).map(|x| x as _).collect();
assert_eq!(basic_simd_sum(&numbers[1..99]), 4949.0);
pub fn as_simd_mut<const LANES: usize>(
&mut self
) -> (&mut [T], &mut [Simd<T, LANES>], &mut [T]) where
T: SimdElement,
Simd<T, LANES>: AsMut<[T; LANES]>,
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
T: SimdElement,
Simd<T, LANES>: AsMut<[T; LANES]>,
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
.
🔬 This is a nightly-only experimental API. (is_sorted
)
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());
🔬 This is a nightly-only experimental API. (is_sorted
)
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.
🔬 This is a nightly-only experimental API. (is_sorted
)
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()));
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)));
🔬 This is a nightly-only experimental API. (slice_take
)
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));
pub 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));
🔬 This is a nightly-only experimental API. (slice_take
)
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');
🔬 This is a nightly-only experimental API. (slice_take
)
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');
🔬 This is a nightly-only experimental API. (slice_take
)
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');
🔬 This is a nightly-only experimental API. (slice_take
)
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');
Checks if all bytes in this slice are within the ASCII range.
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.
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
.
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
.
🔬 This is a nightly-only experimental API. (inherent_ascii_escape
)
inherent_ascii_escape
)Returns an iterator that produces an escaped version of this slice, treating it as an ASCII string.
Examples
#![feature(inherent_ascii_escape)]
let s = b"0\t\r\n'\"\\\x9d";
let escaped = s.escape_ascii().to_string();
assert_eq!(escaped, "0\\t\\r\\n\\'\\\"\\\\\\x9d");
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]);
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]);
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]);
Sorts the slice with a key extraction function.
This sort is stable (i.e., does not reorder equal elements) and O(m * n * log(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]);
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]);
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.
🔬 This is a nightly-only experimental API. (allocator_api
)
allocator_api
)Copies self
into a new Vec
with an allocator.
Examples
#![feature(allocator_api)]
use std::alloc::System;
let s = [10, 40, 30];
let x = s.to_vec_in(System);
// Here, `s` and `x` can be modified independently.
Flattens a slice of T
into a single value Self::Output
.
Examples
assert_eq!(["hello", "world"].concat(), "helloworld");
assert_eq!([[1, 2], [3, 4]].concat(), [1, 2, 3, 4]);
Flattens a slice of T
into a single value Self::Output
, placing a
given separator between each.
Examples
assert_eq!(["hello", "world"].join(" "), "hello world");
assert_eq!([[1, 2], [3, 4]].join(&0), [1, 2, 0, 3, 4]);
assert_eq!([[1, 2], [3, 4]].join(&[0, 0][..]), [1, 2, 0, 0, 3, 4]);
1.0.0[src]pub fn connect<Separator>(
&self,
sep: Separator
) -> <[T] as Join<Separator>>::Outputⓘ where
[T]: Join<Separator>,
👎 Deprecated since 1.3.0: renamed to join
pub fn connect<Separator>(
&self,
sep: Separator
) -> <[T] as Join<Separator>>::Outputⓘ where
[T]: Join<Separator>,
renamed to join
Flattens a slice of T
into a single value Self::Output
, placing a
given separator between each.
Examples
assert_eq!(["hello", "world"].connect(" "), "hello world");
assert_eq!([[1, 2], [3, 4]].connect(&0), [1, 2, 0, 3, 4]);
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
.
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
Returns the contents of the internal buffer, filling it with more data from the inner reader if it is empty. Read more
Tells this buffer that amt
bytes have been consumed from the buffer,
so they should no longer be returned in calls to read
. Read more
buf_read_has_data_left
)Check if the underlying Read
has any data left to be read. Read more
Read all bytes into buf
until the delimiter byte
or EOF is reached. Read more
Read all bytes until a newline (the 0xA
byte) is reached, and append
them to the provided buffer. Read more
Returns an iterator over the contents of this reader split on the byte
byte
. Read more
impl<'de, T, const N: usize> Deserialize<'de> for StaticVec<T, N> where
T: Deserialize<'de>,
This is supported on crate feature serde
only.
impl<'de, T, const N: usize> Deserialize<'de> for StaticVec<T, N> where
T: Deserialize<'de>,
serde
only.Deserialize this value from the given Serde deserializer. Read more
Extends a collection with the contents of an iterator. Read more
extend_one
)Extends a collection with exactly one element.
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
Extends a collection with the contents of an iterator. Read more
extend_one
)Extends a collection with exactly one element.
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
Creates a new StaticVec instance from the contents of values
, using
new_from_slice
internally.
Creates a new StaticVec instance from the contents of values
, using
new_from_slice
internally.
Creates a new StaticVec instance from the contents of values
, using
new_from_slice
internally.
Creates a new StaticVec instance from the contents of values
, using
new_from_slice
internally.
Creates a new StaticVec instance from the contents of values
, using
new_from_slice
internally.
Creates a new StaticVec instance from the contents of values
, using
new_from_slice
internally.
Creates a new StaticVec instance from the contents of values
, using
new_from_array
internally.
Performs the conversion.
Performs the conversion.
Converts a StaticVec<T, N>
into a StaticHeap<T, N>
.
This conversion happens in-place, and has O(n)
time complexity.
Converts a StaticVec<T, N1>
into a StaticHeap<T, N2>
.
This conversion happens in-place, and has O(n)
time complexity.
Creates a value from an iterator. Read more
Creates a value from an iterator. Read more
Asserts that the lower bound of index
is less than or equal to its upper bound,
and that its upper bound is less than or equal to the current length of the StaticVec,
and if so returns a constant reference to a slice of elements index.start..index.end
.
Asserts that the lower bound of index
is less than or equal to the
current length of the StaticVec, and if so returns a constant reference
to a slice of elements index.start()..self.length
.
Asserts that the lower bound of index
is less than or equal to its upper bound,
and that its upper bound is less than the current length of the StaticVec,
and if so returns a constant reference to a slice of elements index.start()..=index.end()
.
Asserts that the lower bound of index
is less than or equal to its upper bound,
and that its upper bound is less than or equal to the current length of the StaticVec,
and if so returns a mutable reference to a slice of elements index.start..index.end
.
Returns a mutable reference to a slice consisting of 0..self.length
elements of the StaticVec, using as_mut_slice internally.
Asserts that the lower bound of index
is less than or equal to its upper bound,
and that its upper bound is less than the current length of the StaticVec,
and if so returns a mutable reference to a slice of elements index.start()..=index.end()
.
Asserts that the upper bound of index
is less than the
current length of the StaticVec, and if so returns a constant reference
to a slice of elements 0..=index.end
.
Returns a StaticVecIterConst
over the StaticVec’s
inhabited area.
type IntoIter = StaticVecIterConst<'a, T, N>
type IntoIter = StaticVecIterConst<'a, T, N>
Which kind of iterator are we turning this into?
Returns a StaticVecIterMut
over the StaticVec’s
inhabited area.
type IntoIter = StaticVecIterMut<'a, T, N>
type IntoIter = StaticVecIterMut<'a, T, N>
Which kind of iterator are we turning this into?
Returns a by-value StaticVecIntoIter
over the
StaticVec’s inhabited area, which consumes the StaticVec.
type IntoIter = StaticVecIntoIter<T, N>
type IntoIter = StaticVecIntoIter<T, N>
Which kind of iterator are we turning this into?
type Item = T
type Item = T
The type of the elements being iterated over.
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<&'_ [T1; N1]> for StaticVec<T2, N2>
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<&'_ [T1; N1]> for StaticVec<T2, N2>
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<&'_ StaticVec<T1, N1>> for StaticVec<T2, N2>
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<&'_ StaticVec<T1, N1>> for StaticVec<T2, N2>
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<&'_ mut [T1; N1]> for StaticVec<T2, N2>
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<&'_ mut [T1; N1]> for StaticVec<T2, N2>
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<&'_ mut StaticVec<T1, N1>> for StaticVec<T2, N2>
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<&'_ mut StaticVec<T1, N1>> for StaticVec<T2, N2>
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<[T1; N1]> for StaticVec<T2, N2>
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<[T1; N1]> for StaticVec<T2, N2>
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<[T1; N1]> for &StaticVec<T2, N2>
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<[T1; N1]> for &StaticVec<T2, N2>
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<[T1; N1]> for &mut StaticVec<T2, N2>
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<[T1; N1]> for &mut StaticVec<T2, N2>
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<StaticVec<T1, N1>> for StaticVec<T2, N2>
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<StaticVec<T1, N1>> for StaticVec<T2, N2>
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<StaticVec<T1, N1>> for &StaticVec<T2, N2>
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<StaticVec<T1, N1>> for &StaticVec<T2, N2>
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<StaticVec<T1, N1>> for &mut StaticVec<T2, N2>
impl<T1, T2: PartialOrd<T1>, const N1: usize, const N2: usize> PartialOrd<StaticVec<T1, N1>> for &mut StaticVec<T2, N2>
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
Read from a StaticVec. This implementation operates by copying bytes into the destination buffers, then shifting the remaining bytes over.
Pull some bytes from this source into the specified buffer, returning how many bytes were read. Read more
Read all bytes until EOF in this source, placing them into buf
. Read more
Read all bytes until EOF in this source, appending them to buf
. Read more
Read the exact number of bytes required to fill buf
. Read more
Like read
, except that it reads into a slice of buffers. Read more
read_buf
)Pull some bytes from this source into the specified buffer. Read more
can_vector
)Determines if this Read
er has an efficient read_vectored
implementation. Read more
read_buf
)Read the exact number of bytes required to fill buf
. Read more
Creates a “by reference” adaptor for this instance of Read
. Read more
Creates an adapter which will chain this stream with another. Read more
Writes a string slice into this writer, returning whether the write succeeded. Read more
Write a buffer into this writer, returning how many bytes were written. Read more
Attempts to write an entire buffer into this writer. Read more
Flush this output stream, ensuring that all intermediately buffered contents reach their destination. Read more
can_vector
)Determines if this Write
r has an efficient write_vectored
implementation. Read more
write_all_vectored
)Attempts to write multiple buffers into this writer. Read more
Writes a formatted string into this writer, returning any error encountered. Read more
Auto Trait Implementations
impl<T, const N: usize> RefUnwindSafe for StaticVec<T, N> where
T: RefUnwindSafe,
impl<T, const N: usize> UnwindSafe for StaticVec<T, N> where
T: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more