std::vec::Vec - Rust (original) (raw)
Struct std::vec::Vec1.0.0 [−] [src]
pub struct Vec { /* fields omitted */ }
A contiguous growable array type, written Vec<T> but pronounced 'vector'.
let mut vec = Vec::new(); vec.push(1); vec.push(2);
assert_eq!(vec.len(), 2); assert_eq!(vec[0], 1);
assert_eq!(vec.pop(), Some(2)); assert_eq!(vec.len(), 1);
vec[0] = 7; assert_eq!(vec[0], 7);
vec.extend([1, 2, 3].iter().cloned());
for x in &vec { println!("{}", x); } assert_eq!(vec, [7, 1, 2, 3]);Run
The vec! macro is provided to make initialization more convenient:
let mut vec = vec![1, 2, 3]; vec.push(4); assert_eq!(vec, [1, 2, 3, 4]);Run
It can also initialize each element of a Vec<T> with a given value:
let vec = vec![0; 5]; assert_eq!(vec, [0, 0, 0, 0, 0]);Run
Use a Vec<T> as an efficient stack:
let mut stack = Vec::new();
stack.push(1); stack.push(2); stack.push(3);
while let Some(top) = stack.pop() {
println!("{}", top);}Run
The Vec type allows to access values by index, because it implements theIndex trait. An example will be more explicit:
let v = vec![0, 2, 4, 6]; println!("{}", v[1]); Run
However be careful: if you try to access an index which isn't in the Vec, your software will panic! You cannot do this:
let v = vec![0, 2, 4, 6]; println!("{}", v[6]); Run
In conclusion: always check if the index you want to get really exists before doing it.
A Vec can be mutable. Slices, on the other hand, are read-only objects. To get a slice, use &. Example:
fn read_slice(slice: &[usize]) {
}
let v = vec![0, 1]; read_slice(&v);
let x : &[usize] = &v;Run
In Rust, it's more common to pass slices as arguments rather than vectors when you just want to provide a read access. The same goes for String and&str.
Capacity and reallocation
The capacity of a vector is the amount of space allocated for any future elements that will be added onto the vector. This is not to be confused with the length of a vector, which specifies the number of actual elements within the vector. If a vector's length exceeds its capacity, its capacity will automatically be increased, but its elements will have to be reallocated.
For example, a vector with capacity 10 and length 0 would be an empty vector with space for 10 more elements. Pushing 10 or fewer elements onto the vector will not change its capacity or cause reallocation to occur. However, if the vector's length is increased to 11, it will have to reallocate, which can be slow. For this reason, it is recommended to use Vec::with_capacitywhenever possible to specify how big the vector is expected to get.
Due to its incredibly fundamental nature, Vec makes a lot of guarantees about its design. This ensures that it's as low-overhead as possible in the general case, and can be correctly manipulated in primitive ways by unsafe code. Note that these guarantees refer to an unqualified Vec<T>. If additional type parameters are added (e.g. to support custom allocators), overriding their defaults may change the behavior.
Most fundamentally, Vec is and always will be a (pointer, capacity, length) triplet. No more, no less. The order of these fields is completely unspecified, and you should use the appropriate methods to modify these. The pointer will never be null, so this type is null-pointer-optimized.
However, the pointer may not actually point to allocated memory. In particular, if you construct a Vec with capacity 0 via Vec::new, vec![],Vec::with_capacity(0), or by calling shrink_to_fiton an empty Vec, it will not allocate memory. Similarly, if you store zero-sized types inside a Vec, it will not allocate space for them. Note that in this case the Vec may not report a capacity of 0. Vec will allocate if and only if mem::size_of::() * capacity() > 0. In general, Vec's allocation details are very subtle — if you intend to allocate memory using a Vecand use it for something else (either to pass to unsafe code, or to build your own memory-backed collection), be sure to deallocate this memory by usingfrom_raw_parts to recover the Vec and then dropping it.
If a Vec has allocated memory, then the memory it points to is on the heap (as defined by the allocator Rust is configured to use by default), and its pointer points to len initialized elements in order (what you would see if you coerced it to a slice), followed by capacity-lenlogically uninitialized elements.
Vec will never perform a "small optimization" where elements are actually stored on the stack for two reasons:
- It would make it more difficult for unsafe code to correctly manipulate a
Vec. The contents of aVecwouldn't have a stable address if it were only moved, and it would be more difficult to determine if aVechad actually allocated memory. - It would penalize the general case, incurring an additional branch on every access.
Vec will never automatically shrink itself, even if completely empty. This ensures no unnecessary allocations or deallocations occur. Emptying a Vecand then filling it back up to the same len should incur no calls to the allocator. If you wish to free up unused memory, useshrink_to_fit.
push and insert will never (re)allocate if the reported capacity is sufficient. push and insert will (re)allocate iflen==capacity. That is, the reported capacity is completely accurate, and can be relied on. It can even be used to manually free the memory allocated by a Vec if desired. Bulk insertion methods may reallocate, even when not necessary.
Vec does not guarantee any particular growth strategy when reallocating when full, nor when reserve is called. The current strategy is basic and it may prove desirable to use a non-constant growth factor. Whatever strategy is used will of course guarantee O(1) amortized push.
vec![x; n], vec![a, b, c, d], andVec::with_capacity(n), will all produce a Vecwith exactly the requested capacity. If len==capacity, (as is the case for the vec! macro), then a Vec<T> can be converted to and from a Box<[T]> without reallocating or moving the elements.
Vec will not specifically overwrite any data that is removed from it, but also won't specifically preserve it. Its uninitialized memory is scratch space that it may use however it wants. It will generally just do whatever is most efficient or otherwise easy to implement. Do not rely on removed data to be erased for security purposes. Even if you drop a Vec, its buffer may simply be reused by another Vec. Even if you zero a Vec's memory first, that may not actually happen because the optimizer does not consider this a side-effect that must be preserved. There is one case which we will not break, however: using unsafe code to write to the excess capacity, and then increasing the length to match, is always valid.
Vec does not currently guarantee the order in which elements are dropped (the order has changed in the past, and may change again).
impl<T> [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
pub fn [new](#method.new)() -> [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
Constructs a new, empty Vec<T>.
The vector will not allocate until elements are pushed onto it.
let mut vec: Vec = Vec::new();Run
pub fn [with_capacity](#method.with%5Fcapacity)(capacity: [usize](../primitive.usize.html)) -> [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
Constructs a new, empty Vec<T> with the specified capacity.
The vector will be able to hold exactly capacity elements without reallocating. If capacity is 0, the vector will not allocate.
It is important to note that this function does not specify the _length_of the returned vector, but only the capacity. For an explanation of the difference between length and capacity, see Capacity and reallocation.
let mut vec = Vec::with_capacity(10);
assert_eq!(vec.len(), 0);
for i in 0..10 { vec.push(i); }
vec.push(11);Run
pub unsafe fn [from_raw_parts](#method.from%5Fraw%5Fparts)( ptr: [*mut T](../primitive.pointer.html), length: [usize](../primitive.usize.html), capacity: [usize](../primitive.usize.html) ) -> [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
Creates a Vec<T> directly from the raw components of another vector.
This is highly unsafe, due to the number of invariants that aren't checked:
ptrneeds to have been previously allocated via String/Vec<T>(at least, it's highly likely to be incorrect if it wasn't).ptr'sTneeds to have the same size and alignment as it was allocated with.lengthneeds to be less than or equal tocapacity.capacityneeds to be the capacity that the pointer was allocated with.
Violating these may cause problems like corrupting the allocator's internal data structures. For example it is not safe to build a Vec<u8> from a pointer to a C char array and a size_t.
The ownership of ptr is effectively transferred to theVec<T> which may then deallocate, reallocate or change the contents of memory pointed to by the pointer at will. Ensure that nothing else uses the pointer after calling this function.
use std::ptr; use std::mem;
fn main() { let mut v = vec![1, 2, 3];
let p = v.as_mut_ptr();
let len = v.len();
let cap = v.capacity();
unsafe {
mem::forget(v);
for i in 0..len as isize {
ptr::write(p.offset(i), 4 + i);
}
let rebuilt = Vec::from_raw_parts(p, len, cap);
assert_eq!(rebuilt, [4, 5, 6]);
}}Run
pub fn [capacity](#method.capacity)(&self) -> [usize](../primitive.usize.html)[src]
Returns the number of elements the vector can hold without reallocating.
let vec: Vec = Vec::with_capacity(10); assert_eq!(vec.capacity(), 10);Run
pub fn [reserve](#method.reserve)(&mut self, additional: [usize](../primitive.usize.html))[src]
Reserves capacity for at least additional more elements to be inserted in the given Vec<T>. The collection may reserve more space to avoid frequent reallocations. After calling reserve, capacity will be greater than or equal to self.len() + additional. Does nothing if capacity is already sufficient.
Panics if the new capacity overflows usize.
let mut vec = vec![1]; vec.reserve(10); assert!(vec.capacity() >= 11);Run
pub fn [reserve_exact](#method.reserve%5Fexact)(&mut self, additional: [usize](../primitive.usize.html))[src]
Reserves the minimum capacity for exactly additional more elements to be inserted in the given Vec<T>. After calling reserve_exact, capacity will be greater than or equal to self.len() + additional. Does nothing if the capacity is already sufficient.
Note that the allocator may give the collection more space than it requests. Therefore capacity can not be relied upon to be precisely minimal. Prefer reserve if future insertions are expected.
Panics if the new capacity overflows usize.
let mut vec = vec![1]; vec.reserve_exact(10); assert!(vec.capacity() >= 11);Run
pub fn [shrink_to_fit](#method.shrink%5Fto%5Ffit)(&mut self)[src]
Shrinks the capacity of the vector as much as possible.
It will drop down as close as possible to the length but the allocator may still inform the vector that there is space for a few more elements.
let mut vec = Vec::with_capacity(10); vec.extend([1, 2, 3].iter().cloned()); assert_eq!(vec.capacity(), 10); vec.shrink_to_fit(); assert!(vec.capacity() >= 3);Run
ⓘImportant traits for Box
pub fn [into_boxed_slice](#method.into%5Fboxed%5Fslice)(self) -> [Box](../../std/boxed/struct.Box.html "struct std::boxed::Box")<[[](../primitive.slice.html)T[]](../primitive.slice.html)>[src]
Converts the vector into Box<[T]>.
Note that this will drop any excess capacity.
let v = vec![1, 2, 3];
let slice = v.into_boxed_slice();Run
Any excess capacity is removed:
let mut vec = Vec::with_capacity(10); vec.extend([1, 2, 3].iter().cloned());
assert_eq!(vec.capacity(), 10); let slice = vec.into_boxed_slice(); assert_eq!(slice.into_vec().capacity(), 3);Run
pub fn [truncate](#method.truncate)(&mut self, len: [usize](../primitive.usize.html))[src]
Shortens the vector, keeping the first len elements and dropping the rest.
If len is greater than the vector's current length, this has no effect.
The drain method can emulate truncate, but causes the excess elements to be returned instead of dropped.
Note that this method has no effect on the allocated capacity of the vector.
Truncating a five element vector to two elements:
let mut vec = vec![1, 2, 3, 4, 5]; vec.truncate(2); assert_eq!(vec, [1, 2]);Run
No truncation occurs when len is greater than the vector's current length:
let mut vec = vec![1, 2, 3]; vec.truncate(8); assert_eq!(vec, [1, 2, 3]);Run
Truncating when len == 0 is equivalent to calling the clearmethod.
let mut vec = vec![1, 2, 3]; vec.truncate(0); assert_eq!(vec, []);Run
pub fn [as_slice](#method.as%5Fslice)(&self) -> [&[T]](../primitive.slice.html)
1.7.0
Extracts a slice containing the entire vector.
Equivalent to &s[..].
use std::io::{self, Write}; let buffer = vec![1, 2, 3, 5, 8]; io::sink().write(buffer.as_slice()).unwrap();Run
pub fn [as_mut_slice](#method.as%5Fmut%5Fslice)(&mut self) -> [&mut [T]](../primitive.slice.html)
1.7.0
Extracts a mutable slice of the entire vector.
Equivalent to &mut s[..].
use std::io::{self, Read}; let mut buffer = vec![0; 3]; io::repeat(0b101).read_exact(buffer.as_mut_slice()).unwrap();Run
pub unsafe fn [set_len](#method.set%5Flen)(&mut self, len: [usize](../primitive.usize.html))[src]
Sets the length of a vector.
This will explicitly set the size of the vector, without actually modifying its buffers, so it is up to the caller to ensure that the vector is actually the specified size.
use std::ptr;
let mut vec = vec!['r', 'u', 's', 't'];
unsafe { ptr::drop_in_place(&mut vec[3]); vec.set_len(3); } assert_eq!(vec, ['r', 'u', 's']);Run
In this example, there is a memory leak since the memory locations owned by the inner vectors were not freed prior to the set_len call:
let mut vec = vec![vec![1, 0, 0], vec![0, 1, 0], vec![0, 0, 1]]; unsafe { vec.set_len(0); }Run
In this example, the vector gets expanded from zero to four items without any memory allocations occurring, resulting in vector values of unallocated memory:
let mut vec: Vec = Vec::new();
unsafe { vec.set_len(4); }Run
pub fn [swap_remove](#method.swap%5Fremove)(&mut self, index: [usize](../primitive.usize.html)) -> T[src]
Removes an element from the vector and returns it.
The removed element is replaced by the last element of the vector.
This does not preserve ordering, but is O(1).
Panics if index is out of bounds.
let mut v = vec!["foo", "bar", "baz", "qux"];
assert_eq!(v.swap_remove(1), "bar"); assert_eq!(v, ["foo", "qux", "baz"]);
assert_eq!(v.swap_remove(0), "foo"); assert_eq!(v, ["baz", "qux"]);Run
pub fn [insert](#method.insert)(&mut self, index: [usize](../primitive.usize.html), element: T)[src]
Inserts an element at position index within the vector, shifting all elements after it to the right.
Panics if index > len.
let mut vec = vec![1, 2, 3]; vec.insert(1, 4); assert_eq!(vec, [1, 4, 2, 3]); vec.insert(4, 5); assert_eq!(vec, [1, 4, 2, 3, 5]);Run
pub fn [remove](#method.remove)(&mut self, index: [usize](../primitive.usize.html)) -> T[src]
Removes and returns the element at position index within the vector, shifting all elements after it to the left.
Panics if index is out of bounds.
let mut v = vec![1, 2, 3]; assert_eq!(v.remove(1), 2); assert_eq!(v, [1, 3]);Run
`pub fn retain(&mut self, f: F) where
Retains only the elements specified by the predicate.
In other words, remove all elements e such that f(&e) returns false. This method operates in place and preserves the order of the retained elements.
let mut vec = vec![1, 2, 3, 4]; vec.retain(|&x| x%2 == 0); assert_eq!(vec, [2, 4]);Run
`pub fn dedup_by_key<F, K>(&mut self, key: F) where
F: FnMut(&mut T) -> K,
K: PartialEq, `
1.16.0
Removes all but the first of consecutive elements in the vector that resolve to the same key.
If the vector is sorted, this removes all duplicates.
let mut vec = vec![10, 20, 21, 30, 20];
vec.dedup_by_key(|i| *i / 10);
assert_eq!(vec, [10, 20, 30, 20]);Run
`pub fn dedup_by(&mut self, same_bucket: F) where
F: FnMut(&mut T, &mut T) -> bool, `
1.16.0
Removes all but the first of consecutive elements in the vector satisfying a given equality relation.
The same_bucket function is passed references to two elements from the vector, and returns true if the elements compare equal, or false if they do not. The elements are passed in opposite order from their order in the vector, so if same_bucket(a, b) returnstrue, a is removed.
If the vector is sorted, this removes all duplicates.
let mut vec = vec!["foo", "bar", "Bar", "baz", "bar"];
vec.dedup_by(|a, b| a.eq_ignore_ascii_case(b));
assert_eq!(vec, ["foo", "bar", "baz", "bar"]);Run
pub fn [push](#method.push)(&mut self, value: T)[src]
Appends an element to the back of a collection.
Panics if the number of elements in the vector overflows a usize.
let mut vec = vec![1, 2]; vec.push(3); assert_eq!(vec, [1, 2, 3]);Run
pub fn [place_back](#method.place%5Fback)(&mut self) -> [PlaceBack](../../std/vec/struct.PlaceBack.html "struct std::vec::PlaceBack")<T>[src]
🔬 This is a nightly-only experimental API. (collection_placement #30172)
placement protocol is subject to change
Returns a place for insertion at the back of the Vec.
Using this method with placement syntax is equivalent to push, but may be more efficient.
#![feature(collection_placement)] #![feature(placement_in_syntax)]
let mut vec = vec![1, 2]; vec.place_back() <- 3; vec.place_back() <- 4; assert_eq!(&vec, &[1, 2, 3, 4]);Run
pub fn [pop](#method.pop)(&mut self) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<T>[src]
Removes the last element from a vector and returns it, or None if it is empty.
let mut vec = vec![1, 2, 3]; assert_eq!(vec.pop(), Some(3)); assert_eq!(vec, [1, 2]);Run
pub fn [append](#method.append)(&mut self, other: &mut [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>)
1.4.0
Moves all the elements of other into Self, leaving other empty.
Panics if the number of elements in the vector overflows a usize.
let mut vec = vec![1, 2, 3]; let mut vec2 = vec![4, 5, 6]; vec.append(&mut vec2); assert_eq!(vec, [1, 2, 3, 4, 5, 6]); assert_eq!(vec2, []);Run
ⓘImportant traits for Drain<'a, T>
pub fn [drain](#method.drain)<R>(&mut self, range: R) -> [Drain](../../std/vec/struct.Drain.html "struct std::vec::Drain")<T> where R: [RangeArgument](../../std/collections/range/trait.RangeArgument.html "trait std::collections::range::RangeArgument")<[usize](../primitive.usize.html)>,
1.6.0
Creates a draining iterator that removes the specified range in the vector and yields the removed items.
Note 1: The element range is removed even if the iterator is only partially consumed or not consumed at all.
Note 2: It is unspecified how many elements are removed from the vector if the Drain value is leaked.
Panics if the starting point is greater than the end point or if the end point is greater than the length of the vector.
let mut v = vec![1, 2, 3]; let u: Vec<_> = v.drain(1..).collect(); assert_eq!(v, &[1]); assert_eq!(u, &[2, 3]);
v.drain(..); assert_eq!(v, &[]);Run
pub fn [clear](#method.clear)(&mut self)[src]
Clears the vector, removing all values.
Note that this method has no effect on the allocated capacity of the vector.
let mut v = vec![1, 2, 3];
v.clear();
assert!(v.is_empty());Run
pub fn [len](#method.len)(&self) -> [usize](../primitive.usize.html)[src]
Returns the number of elements in the vector, also referred to as its 'length'.
let a = vec![1, 2, 3]; assert_eq!(a.len(), 3);Run
pub fn [is_empty](#method.is%5Fempty)(&self) -> [bool](../primitive.bool.html)[src]
Returns true if the vector contains no elements.
let mut v = Vec::new(); assert!(v.is_empty());
v.push(1); assert!(!v.is_empty());Run
pub fn [split_off](#method.split%5Foff)(&mut self, at: [usize](../primitive.usize.html)) -> [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>
1.4.0
Splits the collection into two at the given index.
Returns a newly allocated Self. self contains elements [0, at), and the returned Self contains elements [at, len).
Note that the capacity of self does not change.
Panics if at > len.
let mut vec = vec![1,2,3]; let vec2 = vec.split_off(1); assert_eq!(vec, [1]); assert_eq!(vec2, [2, 3]);Run
`impl Vec where
pub fn [resize](#method.resize)(&mut self, new_len: [usize](../primitive.usize.html), value: T)
1.5.0
Resizes the Vec in-place so that len is equal to new_len.
If new_len is greater than len, the Vec is extended by the difference, with each additional slot filled with value. If new_len is less than len, the Vec is simply truncated.
This method requires Clone to clone the passed value. If you'd rather create a value with Default instead, see resize_default.
let mut vec = vec!["hello"]; vec.resize(3, "world"); assert_eq!(vec, ["hello", "world", "world"]);
let mut vec = vec![1, 2, 3, 4]; vec.resize(2, 0); assert_eq!(vec, [1, 2]);Run
pub fn [extend_from_slice](#method.extend%5Ffrom%5Fslice)(&mut self, other: [&[T]](../primitive.slice.html))
1.6.0
Clones and appends all elements in a slice to the Vec.
Iterates over the slice other, clones each element, and then appends it to this Vec. The other vector is traversed in-order.
Note that this function is same as extend except that it is specialized to work with slices instead. If and when Rust gets specialization this function will likely be deprecated (but still available).
let mut vec = vec![1]; vec.extend_from_slice(&[2, 3, 4]); assert_eq!(vec, [1, 2, 3, 4]);Run
`impl Vec where
pub fn [resize_default](#method.resize%5Fdefault)(&mut self, new_len: [usize](../primitive.usize.html))[src]
🔬 This is a nightly-only experimental API. (vec_resize_default #41758)
Resizes the Vec in-place so that len is equal to new_len.
If new_len is greater than len, the Vec is extended by the difference, with each additional slot filled with Default::default(). If new_len is less than len, the Vec is simply truncated.
This method uses Default to create new values on every push. If you'd rather Clone a given value, use resize.
#![feature(vec_resize_default)]
let mut vec = vec![1, 2, 3]; vec.resize_default(5); assert_eq!(vec, [1, 2, 3, 0, 0]);
let mut vec = vec![1, 2, 3, 4]; vec.resize_default(2); assert_eq!(vec, [1, 2]);Run
`impl Vec where
pub fn [dedup](#method.dedup)(&mut self)[src]
Removes consecutive repeated elements in the vector.
If the vector is sorted, this removes all duplicates.
let mut vec = vec![1, 2, 2, 3, 2];
vec.dedup();
assert_eq!(vec, [1, 2, 3, 2]);Run
pub fn [remove_item](#method.remove%5Fitem)(&mut self, item: [&](../primitive.reference.html)T) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<T>[src]
🔬 This is a nightly-only experimental API. (vec_remove_item #40062)
recently added
Removes the first instance of item from the vector if the item exists.
let mut vec = vec![1, 2, 3, 1];
vec.remove_item(&1);
assert_eq!(vec, vec![2, 3, 1]);Run
impl<T> [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
ⓘImportant traits for Splice<'a, I>
pub fn [splice](#method.splice)<R, I>( &mut self, range: R, replace_with: I ) -> [Splice](../../std/vec/struct.Splice.html "struct std::vec::Splice")<<I as [IntoIterator](../../std/iter/trait.IntoIterator.html "trait std::iter::IntoIterator")>::[IntoIter](../../std/iter/trait.IntoIterator.html#associatedtype.IntoIter "type std::iter::IntoIterator::IntoIter")> where I: [IntoIterator](../../std/iter/trait.IntoIterator.html "trait std::iter::IntoIterator")<Item = T>, R: [RangeArgument](../../std/collections/range/trait.RangeArgument.html "trait std::collections::range::RangeArgument")<[usize](../primitive.usize.html)>,
1.21.0
Creates a splicing iterator that replaces the specified range in the vector with the given replace_with iterator and yields the removed items.replace_with does not need to be the same length as range.
Note 1: The element range is removed even if the iterator is not consumed until the end.
Note 2: It is unspecified how many elements are removed from the vector, if the Splice value is leaked.
Note 3: The input iterator replace_with is only consumed when the Splice value is dropped.
Note 4: This is optimal if:
- The tail (elements in the vector after
range) is empty, - or
replace_withyields fewer elements thanrange’s length - or the lower bound of its
size_hint()is exact.
Otherwise, a temporary vector is allocated and the tail is moved twice.
Panics if the starting point is greater than the end point or if the end point is greater than the length of the vector.
let mut v = vec![1, 2, 3]; let new = [7, 8]; let u: Vec<_> = v.splice(..2, new.iter().cloned()).collect(); assert_eq!(v, &[7, 8, 3]); assert_eq!(u, &[1, 2]);Run
`pub fn drain_filter(&mut self, filter: F) -> DrainFilter<T, F> where
F: FnMut(&mut T) -> bool, `[src]
🔬 This is a nightly-only experimental API. (drain_filter #43244)
recently added
Creates an iterator which uses a closure to determine if an element should be removed.
If the closure returns true, then the element is removed and yielded. If the closure returns false, it will try again, and call the closure on the next element, seeing if it passes the test.
Using this method is equivalent to the following code:
let mut i = 0; while i != vec.len() { if some_predicate(&mut vec[i]) { let val = vec.remove(i);
} else {
i += 1;
}} Run
But drain_filter is easier to use. drain_filter is also more efficient, because it can backshift the elements of the array in bulk.
Note that drain_filter also lets you mutate every element in the filter closure, regardless of whether you choose to keep or remove it.
Splitting an array into evens and odds, reusing the original allocation:
#![feature(drain_filter)] let mut numbers = vec![1, 2, 3, 4, 5, 6, 8, 9, 11, 13, 14, 15];
let evens = numbers.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>(); let odds = numbers;
assert_eq!(evens, vec![2, 4, 6, 8, 14]); assert_eq!(odds, vec![1, 3, 5, 9, 11, 13, 15]);Run
pub fn [len](#method.len-1)(&self) -> [usize](../primitive.usize.html)[src]
Returns the number of elements in the slice.
let a = [1, 2, 3]; assert_eq!(a.len(), 3);Run
pub fn [is_empty](#method.is%5Fempty-1)(&self) -> [bool](../primitive.bool.html)[src]
Returns true if the slice has a length of 0.
let a = [1, 2, 3]; assert!(!a.is_empty());Run
pub fn [first](#method.first)(&self) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[&](../primitive.reference.html)T>[src]
Returns the first element of the slice, or None if it is empty.
let v = [10, 40, 30]; assert_eq!(Some(&10), v.first());
let w: &[i32] = &[]; assert_eq!(None, w.first());Run
pub fn [first_mut](#method.first%5Fmut)(&mut self) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[&mut ](../primitive.reference.html)T>[src]
Returns a mutable pointer to the first element of the slice, or None if it is empty.
let x = &mut [0, 1, 2];
if let Some(first) = x.first_mut() { *first = 5; } assert_eq!(x, &[5, 1, 2]);Run
pub fn [split_first](#method.split%5Ffirst)(&self) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[(](../primitive.tuple.html)[&](../primitive.reference.html)T, [&[T]](../primitive.slice.html)[)](../primitive.tuple.html)>
1.5.0
Returns the first and all the rest of the elements of the slice, or None if it is empty.
let x = &[0, 1, 2];
if let Some((first, elements)) = x.split_first() { assert_eq!(first, &0); assert_eq!(elements, &[1, 2]); }Run
pub fn [split_first_mut](#method.split%5Ffirst%5Fmut)(&mut self) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[(](../primitive.tuple.html)[&mut ](../primitive.reference.html)T, [&mut [T]](../primitive.slice.html)[)](../primitive.tuple.html)>
1.5.0
Returns the first and all the rest of the elements of the slice, or None if it is empty.
let x = &mut [0, 1, 2];
if let Some((first, elements)) = x.split_first_mut() { *first = 3; elements[0] = 4; elements[1] = 5; } assert_eq!(x, &[3, 4, 5]);Run
pub fn [split_last](#method.split%5Flast)(&self) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[(](../primitive.tuple.html)[&](../primitive.reference.html)T, [&[T]](../primitive.slice.html)[)](../primitive.tuple.html)>
1.5.0
Returns the last and all the rest of the elements of the slice, or None if it is empty.
let x = &[0, 1, 2];
if let Some((last, elements)) = x.split_last() { assert_eq!(last, &2); assert_eq!(elements, &[0, 1]); }Run
pub fn [split_last_mut](#method.split%5Flast%5Fmut)(&mut self) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[(](../primitive.tuple.html)[&mut ](../primitive.reference.html)T, [&mut [T]](../primitive.slice.html)[)](../primitive.tuple.html)>
1.5.0
Returns the last and all the rest of the elements of the slice, or None if it is empty.
let x = &mut [0, 1, 2];
if let Some((last, elements)) = x.split_last_mut() { *last = 3; elements[0] = 4; elements[1] = 5; } assert_eq!(x, &[4, 5, 3]);Run
pub fn [last](#method.last)(&self) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[&](../primitive.reference.html)T>[src]
Returns the last element of the slice, or None if it is empty.
let v = [10, 40, 30]; assert_eq!(Some(&30), v.last());
let w: &[i32] = &[]; assert_eq!(None, w.last());Run
pub fn [last_mut](#method.last%5Fmut)(&mut self) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[&mut ](../primitive.reference.html)T>[src]
Returns a mutable pointer to the last item in the slice.
let x = &mut [0, 1, 2];
if let Some(last) = x.last_mut() { *last = 10; } assert_eq!(x, &[0, 1, 10]);Run
`pub fn get(&self, index: I) -> Option<&<I as SliceIndex<T[]>>::Output> where
I: SliceIndex<T[]>, `[src]
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
Noneif out of bounds. - If given a range, returns the subslice corresponding to that range, or
Noneif out of bounds.
let v = [10, 40, 30]; assert_eq!(Some(&40), v.get(1)); assert_eq!(Some(&[10, 40][..]), v.get(0..2)); assert_eq!(None, v.get(3)); assert_eq!(None, v.get(0..4));Run
`pub fn get_mut(
&mut self,
index: I
) -> Option<&mut <I as SliceIndex<T[]>>::Output> where
I: SliceIndex<T[]>, `[src]
Returns a mutable reference to an element or subslice depending on the type of index (see get) or None if the index is out of bounds.
let x = &mut [0, 1, 2];
if let Some(elem) = x.get_mut(1) { *elem = 42; } assert_eq!(x, &[0, 42, 2]);Run
`pub unsafe fn get_unchecked(
&self,
index: I
) -> &<I as SliceIndex<T[]>>::Output where
I: SliceIndex<T[]>, `[src]
Returns a reference to an element or subslice, without doing bounds checking.
This is generally not recommended, use with caution! For a safe alternative see get.
let x = &[1, 2, 4];
unsafe { assert_eq!(x.get_unchecked(1), &2); }Run
`pub unsafe fn get_unchecked_mut(
&mut self,
index: I
) -> &mut <I as SliceIndex<T[]>>::Output where
I: SliceIndex<T[]>, `[src]
Returns a mutable reference to an element or subslice, without doing bounds checking.
This is generally not recommended, use with caution! For a safe alternative see get_mut.
let x = &mut [1, 2, 4];
unsafe { let elem = x.get_unchecked_mut(1); *elem = 13; } assert_eq!(x, &[1, 13, 4]);Run
pub fn [as_ptr](#method.as%5Fptr)(&self) -> [*const T](../primitive.pointer.html)[src]
Returns a raw pointer to the slice's buffer.
The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.
Modifying the container referenced by this slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.
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.offset(i as isize)); } }Run
pub fn [as_mut_ptr](#method.as%5Fmut%5Fptr)(&mut self) -> [*mut T](../primitive.pointer.html)[src]
Returns an unsafe mutable pointer to the slice's buffer.
The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.
Modifying the container referenced by this slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.
let x = &mut [1, 2, 4]; let x_ptr = x.as_mut_ptr();
unsafe { for i in 0..x.len() { *x_ptr.offset(i as isize) += 2; } } assert_eq!(x, &[3, 4, 6]);Run
pub fn [swap](#method.swap)(&mut self, a: [usize](../primitive.usize.html), b: [usize](../primitive.usize.html))[src]
Swaps two elements in the slice.
- a - The index of the first element
- b - The index of the second element
Panics if a or b are out of bounds.
let mut v = ["a", "b", "c", "d"]; v.swap(1, 3); assert!(v == ["a", "d", "c", "b"]);Run
pub fn [reverse](#method.reverse)(&mut self)[src]
Reverses the order of elements in the slice, in place.
let mut v = [1, 2, 3]; v.reverse(); assert!(v == [3, 2, 1]);Run
ⓘImportant traits for Iter<'a, T>
pub fn [iter](#method.iter)(&self) -> [Iter](../../std/slice/struct.Iter.html "struct std::slice::Iter")<T>[src]
Returns an iterator over the slice.
let x = &[1, 2, 4]; let mut iterator = x.iter();
assert_eq!(iterator.next(), Some(&1)); assert_eq!(iterator.next(), Some(&2)); assert_eq!(iterator.next(), Some(&4)); assert_eq!(iterator.next(), None);Run
ⓘImportant traits for IterMut<'a, T>
pub fn [iter_mut](#method.iter%5Fmut)(&mut self) -> [IterMut](../../std/slice/struct.IterMut.html "struct std::slice::IterMut")<T>[src]
Returns an iterator that allows modifying each value.
let x = &mut [1, 2, 4]; for elem in x.iter_mut() { *elem += 2; } assert_eq!(x, &[3, 4, 6]);Run
ⓘImportant traits for Windows<'a, T>
pub fn [windows](#method.windows)(&self, size: [usize](../primitive.usize.html)) -> [Windows](../../std/slice/struct.Windows.html "struct std::slice::Windows")<T>[src]
Returns an iterator over all contiguous windows of lengthsize. The windows overlap. If the slice is shorter thansize, the iterator returns no values.
Panics if size is 0.
let slice = ['r', 'u', 's', 't']; let mut iter = slice.windows(2); assert_eq!(iter.next().unwrap(), &['r', 'u']); assert_eq!(iter.next().unwrap(), &['u', 's']); assert_eq!(iter.next().unwrap(), &['s', 't']); assert!(iter.next().is_none());Run
If the slice is shorter than size:
let slice = ['f', 'o', 'o']; let mut iter = slice.windows(4); assert!(iter.next().is_none());Run
ⓘImportant traits for Chunks<'a, T>
pub fn [chunks](#method.chunks)(&self, chunk_size: [usize](../primitive.usize.html)) -> [Chunks](../../std/slice/struct.Chunks.html "struct std::slice::Chunks")<T>[src]
Returns an iterator over chunk_size elements of the slice at a time. 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 exact_chunks for a variant of this iterator that returns chunks of always exactly chunk_size elements.
Panics if chunk_size is 0.
let slice = ['l', 'o', 'r', 'e', 'm']; let mut iter = slice.chunks(2); assert_eq!(iter.next().unwrap(), &['l', 'o']); assert_eq!(iter.next().unwrap(), &['r', 'e']); assert_eq!(iter.next().unwrap(), &['m']); assert!(iter.next().is_none());Run
pub fn [exact_chunks](#method.exact%5Fchunks)(&self, chunk_size: [usize](../primitive.usize.html)) -> [ExactChunks](../../std/slice/struct.ExactChunks.html "struct std::slice::ExactChunks")<T>[src]
🔬 This is a nightly-only experimental API. (exact_chunks #47115)
Returns an iterator over chunk_size elements of the slice at a time. 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-1elements will be omitted.
Due to each chunk having exactly chunk_size elements, the compiler can often optimize the resulting code better than in the case ofchunks.
Panics if chunk_size is 0.
#![feature(exact_chunks)]
let slice = ['l', 'o', 'r', 'e', 'm']; let mut iter = slice.exact_chunks(2); assert_eq!(iter.next().unwrap(), &['l', 'o']); assert_eq!(iter.next().unwrap(), &['r', 'e']); assert!(iter.next().is_none());Run
pub fn [chunks_mut](#method.chunks%5Fmut)(&mut self, chunk_size: [usize](../primitive.usize.html)) -> [ChunksMut](../../std/slice/struct.ChunksMut.html "struct std::slice::ChunksMut")<T>[src]
Returns an iterator over chunk_size elements of the slice at a time. 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 exact_chunks_mut for a variant of this iterator that returns chunks of always exactly chunk_size elements.
Panics if chunk_size is 0.
let v = &mut [0, 0, 0, 0, 0]; let mut count = 1;
for chunk in v.chunks_mut(2) { for elem in chunk.iter_mut() { *elem += count; } count += 1; } assert_eq!(v, &[1, 1, 2, 2, 3]);Run
pub fn [exact_chunks_mut](#method.exact%5Fchunks%5Fmut)(&mut self, chunk_size: [usize](../primitive.usize.html)) -> [ExactChunksMut](../../std/slice/struct.ExactChunksMut.html "struct std::slice::ExactChunksMut")<T>[src]
🔬 This is a nightly-only experimental API. (exact_chunks #47115)
Returns an iterator over chunk_size elements of the slice at a time. 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-1elements will be omitted.
Due to each chunk having exactly chunk_size elements, the compiler can often optimize the resulting code better than in the case ofchunks_mut.
Panics if chunk_size is 0.
#![feature(exact_chunks)]
let v = &mut [0, 0, 0, 0, 0]; let mut count = 1;
for chunk in v.exact_chunks_mut(2) { for elem in chunk.iter_mut() { *elem += count; } count += 1; } assert_eq!(v, &[1, 1, 2, 2, 0]);Run
pub fn [split_at](#method.split%5Fat)(&self, mid: [usize](../primitive.usize.html)) -> [(](../primitive.tuple.html)[&[T]](../primitive.slice.html), [&[T]](../primitive.slice.html)[)](../primitive.tuple.html)[src]
Divides one slice into two at an index.
The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).
Panics if mid > len.
let v = [1, 2, 3, 4, 5, 6];
{ let (left, right) = v.split_at(0); assert!(left == []); assert!(right == [1, 2, 3, 4, 5, 6]); }
{ let (left, right) = v.split_at(2); assert!(left == [1, 2]); assert!(right == [3, 4, 5, 6]); }
{ let (left, right) = v.split_at(6); assert!(left == [1, 2, 3, 4, 5, 6]); assert!(right == []); }Run
pub fn [split_at_mut](#method.split%5Fat%5Fmut)(&mut self, mid: [usize](../primitive.usize.html)) -> [(](../primitive.tuple.html)[&mut [T]](../primitive.slice.html), [&mut [T]](../primitive.slice.html)[)](../primitive.tuple.html)[src]
Divides one mutable slice into two at an index.
The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).
Panics if mid > len.
let mut v = [1, 0, 3, 0, 5, 6];
{ let (left, right) = v.split_at_mut(2); assert!(left == [1, 0]); assert!(right == [3, 0, 5, 6]); left[1] = 2; right[1] = 4; } assert!(v == [1, 2, 3, 4, 5, 6]);Run
ⓘImportant traits for Split<'a, T, P>
pub fn [split](#method.split)<F>(&self, pred: F) -> [Split](../../std/slice/struct.Split.html "struct std::slice::Split")<T, F> where F: [FnMut](../../std/ops/trait.FnMut.html "trait std::ops::FnMut")([&](../primitive.reference.html)T) -> [bool](../primitive.bool.html), [src]
Returns an iterator over subslices separated by elements that matchpred. The matched element is not contained in the subslices.
let slice = [10, 40, 33, 20]; let mut iter = slice.split(|num| num % 3 == 0);
assert_eq!(iter.next().unwrap(), &[10, 40]); assert_eq!(iter.next().unwrap(), &[20]); assert!(iter.next().is_none());Run
If the first element is matched, an empty slice will be the first item returned by the iterator. Similarly, if the last element in the slice is matched, an empty slice will be the last item returned by the iterator:
let slice = [10, 40, 33]; let mut iter = slice.split(|num| num % 3 == 0);
assert_eq!(iter.next().unwrap(), &[10, 40]); assert_eq!(iter.next().unwrap(), &[]); assert!(iter.next().is_none());Run
If two matched elements are directly adjacent, an empty slice will be present between them:
let slice = [10, 6, 33, 20]; let mut iter = slice.split(|num| num % 3 == 0);
assert_eq!(iter.next().unwrap(), &[10]); assert_eq!(iter.next().unwrap(), &[]); assert_eq!(iter.next().unwrap(), &[20]); assert!(iter.next().is_none());Run
ⓘImportant traits for SplitMut<'a, T, P>
pub fn [split_mut](#method.split%5Fmut)<F>(&mut self, pred: F) -> [SplitMut](../../std/slice/struct.SplitMut.html "struct std::slice::SplitMut")<T, F> where F: [FnMut](../../std/ops/trait.FnMut.html "trait std::ops::FnMut")([&](../primitive.reference.html)T) -> [bool](../primitive.bool.html), [src]
Returns an iterator over mutable subslices separated by elements that match pred. The matched element is not contained in the subslices.
let mut v = [10, 40, 30, 20, 60, 50];
for group in v.split_mut(|num| *num % 3 == 0) { group[0] = 1; } assert_eq!(v, [1, 40, 30, 1, 60, 1]);Run
ⓘImportant traits for RSplit<'a, T, P>
pub fn [rsplit](#method.rsplit)<F>(&self, pred: F) -> [RSplit](../../std/slice/struct.RSplit.html "struct std::slice::RSplit")<T, F> where F: [FnMut](../../std/ops/trait.FnMut.html "trait std::ops::FnMut")([&](../primitive.reference.html)T) -> [bool](../primitive.bool.html), [src]
🔬 This is a nightly-only experimental API. (slice_rsplit #41020)
Returns an iterator over subslices separated by elements that matchpred, starting at the end of the slice and working backwards. The matched element is not contained in the subslices.
#![feature(slice_rsplit)]
let slice = [11, 22, 33, 0, 44, 55]; let mut iter = slice.rsplit(|num| *num == 0);
assert_eq!(iter.next().unwrap(), &[44, 55]); assert_eq!(iter.next().unwrap(), &[11, 22, 33]); assert_eq!(iter.next(), None);Run
As with split(), if the first or last element is matched, an empty slice will be the first (or last) item returned by the iterator.
#![feature(slice_rsplit)]
let v = &[0, 1, 1, 2, 3, 5, 8]; let mut it = v.rsplit(|n| *n % 2 == 0); assert_eq!(it.next().unwrap(), &[]); assert_eq!(it.next().unwrap(), &[3, 5]); assert_eq!(it.next().unwrap(), &[1, 1]); assert_eq!(it.next().unwrap(), &[]); assert_eq!(it.next(), None);Run
`pub fn rsplit_mut(&mut self, pred: F) -> RSplitMut<T, F> where
🔬 This is a nightly-only experimental API. (slice_rsplit #41020)
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.
#![feature(slice_rsplit)]
let mut v = [100, 400, 300, 200, 600, 500];
let mut count = 0; for group in v.rsplit_mut(|num| *num % 3 == 0) { count += 1; group[0] = count; } assert_eq!(v, [3, 400, 300, 2, 600, 1]);Run
ⓘImportant traits for SplitN<'a, T, P>
pub fn [splitn](#method.splitn)<F>(&self, n: [usize](../primitive.usize.html), pred: F) -> [SplitN](../../std/slice/struct.SplitN.html "struct std::slice::SplitN")<T, F> where F: [FnMut](../../std/ops/trait.FnMut.html "trait std::ops::FnMut")([&](../primitive.reference.html)T) -> [bool](../primitive.bool.html), [src]
Returns an iterator over subslices separated by elements that matchpred, 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.
Print the slice split once by numbers divisible by 3 (i.e. [10, 40],[20, 60, 50]):
let v = [10, 40, 30, 20, 60, 50];
for group in v.splitn(2, |num| *num % 3 == 0) { println!("{:?}", group); }Run
`pub fn splitn_mut(&mut self, n: usize, pred: F) -> SplitNMut<T, F> where
Returns an iterator over subslices separated by elements that matchpred, 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.
let mut v = [10, 40, 30, 20, 60, 50];
for group in v.splitn_mut(2, |num| *num % 3 == 0) { group[0] = 1; } assert_eq!(v, [1, 40, 30, 1, 60, 50]);Run
ⓘImportant traits for RSplitN<'a, T, P>
pub fn [rsplitn](#method.rsplitn)<F>(&self, n: [usize](../primitive.usize.html), pred: F) -> [RSplitN](../../std/slice/struct.RSplitN.html "struct std::slice::RSplitN")<T, F> where F: [FnMut](../../std/ops/trait.FnMut.html "trait std::ops::FnMut")([&](../primitive.reference.html)T) -> [bool](../primitive.bool.html), [src]
Returns an iterator over subslices separated by elements that matchpred 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.
Print the slice split once, starting from the end, by numbers divisible by 3 (i.e. [50], [10, 40, 30, 20]):
let v = [10, 40, 30, 20, 60, 50];
for group in v.rsplitn(2, |num| *num % 3 == 0) { println!("{:?}", group); }Run
`pub fn rsplitn_mut(&mut self, n: usize, pred: F) -> RSplitNMut<T, F> where
Returns an iterator over subslices separated by elements that matchpred 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.
let mut s = [10, 40, 30, 20, 60, 50];
for group in s.rsplitn_mut(2, |num| *num % 3 == 0) { group[0] = 1; } assert_eq!(s, [1, 40, 30, 20, 60, 1]);Run
`pub fn contains(&self, x: &T) -> bool where
Returns true if the slice contains an element with the given value.
let v = [10, 40, 30]; assert!(v.contains(&30)); assert!(!v.contains(&50));Run
`pub fn starts_with(&self, needle: &[T]) -> bool where
Returns true if needle is a prefix of the slice.
let v = [10, 40, 30]; assert!(v.starts_with(&[10])); assert!(v.starts_with(&[10, 40])); assert!(!v.starts_with(&[50])); assert!(!v.starts_with(&[10, 50]));Run
Always returns true if needle is an empty slice:
let v = &[10, 40, 30]; assert!(v.starts_with(&[])); let v: &[u8] = &[]; assert!(v.starts_with(&[]));Run
`pub fn ends_with(&self, needle: &[T]) -> bool where
Returns true if needle is a suffix of the slice.
let v = [10, 40, 30]; assert!(v.ends_with(&[30])); assert!(v.ends_with(&[40, 30])); assert!(!v.ends_with(&[50])); assert!(!v.ends_with(&[50, 30]));Run
Always returns true if needle is an empty slice:
let v = &[10, 40, 30]; assert!(v.ends_with(&[])); let v: &[u8] = &[]; assert!(v.ends_with(&[]));Run
`pub fn binary_search(&self, x: &T) -> Result<usize, usize> where
Binary searches this sorted slice for a given element.
If the value is found then Ok is returned, containing the index of the matching element; if the value is not found thenErr is returned, containing the index where a matching element could be inserted while maintaining sorted order.
Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].
let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];
assert_eq!(s.binary_search(&13), Ok(9)); assert_eq!(s.binary_search(&4), Err(7)); assert_eq!(s.binary_search(&100), Err(13)); let r = s.binary_search(&1); assert!(match r { Ok(1...4) => true, _ => false, });Run
`pub fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize> where
F: FnMut(&'a T) -> Ordering, `[src]
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 a matching value is found then returns Ok, containing the index for the matched element; if no match is found thenErr is returned, containing the index where a matching element could be inserted while maintaining sorted order.
Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].
let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];
let seek = 13; assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Ok(9)); let seek = 4; assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(7)); let seek = 100; assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(13)); let seek = 1; let r = s.binary_search_by(|probe| probe.cmp(&seek)); assert!(match r { Ok(1...4) => true, _ => false, });Run
`pub fn binary_search_by_key<'a, B, F>(
&'a self,
b: &B,
f: F
) -> Result<usize, usize> where
B: Ord,
F: FnMut(&'a T) -> B, `
1.10.0
Binary searches this sorted slice with a key extraction function.
Assumes that the slice is sorted by the key, for instance withsort_by_key using the same key extraction function.
If a matching value is found then returns Ok, containing the index for the matched element; if no match is found then Erris returned, containing the index where a matching element could be inserted while maintaining sorted order.
Looks up a series of four elements in a slice of pairs sorted by their second elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].
let s = [(0, 0), (2, 1), (4, 1), (5, 1), (3, 1), (1, 2), (2, 3), (4, 5), (5, 8), (3, 13), (1, 21), (2, 34), (4, 55)];
assert_eq!(s.binary_search_by_key(&13, |&(a,b)| b), Ok(9)); assert_eq!(s.binary_search_by_key(&4, |&(a,b)| b), Err(7)); assert_eq!(s.binary_search_by_key(&100, |&(a,b)| b), Err(13)); let r = s.binary_search_by_key(&1, |&(a,b)| b); assert!(match r { Ok(1...4) => true, _ => false, });Run
`pub fn sort(&mut self) where
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.
The current algorithm is an adaptive, iterative merge sort inspired bytimsort. 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.
let mut v = [-5, 4, 1, -3, 2];
v.sort(); assert!(v == [-5, -3, 1, 2, 4]);Run
`pub fn sort_by(&mut self, compare: F) where
F: FnMut(&T, &T) -> Ordering, `[src]
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.
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.
The current algorithm is an adaptive, iterative merge sort inspired bytimsort. 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.
let mut v = [5, 4, 1, 3, 2]; v.sort_by(|a, b| a.cmp(b)); assert!(v == [1, 2, 3, 4, 5]);
v.sort_by(|a, b| b.cmp(a)); assert!(v == [5, 4, 3, 2, 1]);Run
`pub fn sort_by_key<B, F>(&mut self, f: F) where
1.7.0
Sorts the slice with a key extraction function.
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_by_key.
The current algorithm is an adaptive, iterative merge sort inspired bytimsort. 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.
let mut v = [-5i32, 4, 1, -3, 2];
v.sort_by_key(|k| k.abs()); assert!(v == [1, 2, -3, 4, -5]);Run
`pub fn sort_unstable(&mut self) where
T: Ord, `
1.20.0
Sorts the slice, but may not preserve the order of equal elements.
This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), and O(n log n) worst-case.
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.
let mut v = [-5, 4, 1, -3, 2];
v.sort_unstable(); assert!(v == [-5, -3, 1, 2, 4]);Run
`pub fn sort_unstable_by(&mut self, compare: F) where
F: FnMut(&T, &T) -> Ordering, `
1.20.0
Sorts the slice with a comparator function, but may not preserve the order of equal elements.
This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), and O(n log n) worst-case.
The 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.
let mut v = [5, 4, 1, 3, 2]; v.sort_unstable_by(|a, b| a.cmp(b)); assert!(v == [1, 2, 3, 4, 5]);
v.sort_unstable_by(|a, b| b.cmp(a)); assert!(v == [5, 4, 3, 2, 1]);Run
`pub fn sort_unstable_by_key<B, F>(&mut self, f: F) where
1.20.0
Sorts the slice with a key extraction function, but may not preserve the order of equal elements.
This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), and O(n log n) worst-case.
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.
let mut v = [-5i32, 4, 1, -3, 2];
v.sort_unstable_by_key(|k| k.abs()); assert!(v == [1, 2, -3, 4, -5]);Run
pub fn [rotate_left](#method.rotate%5Fleft)(&mut self, mid: [usize](../primitive.usize.html))[src]
🔬 This is a nightly-only experimental API. (slice_rotate #41891)
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 indexmid will become the first element in the slice.
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.
Takes linear (in self.len()) time.
#![feature(slice_rotate)]
let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; a.rotate_left(2); assert_eq!(a, ['c', 'd', 'e', 'f', 'a', 'b']);Run
Rotating a subslice:
#![feature(slice_rotate)]
let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; a[1..5].rotate_left(1); assert_eq!(a, ['a', 'c', 'd', 'e', 'b', 'f']);Run
pub fn [rotate](#method.rotate)(&mut self, mid: [usize](../primitive.usize.html))[src]
🔬 This is a nightly-only experimental API. (slice_rotate #41891)
pub fn [rotate_right](#method.rotate%5Fright)(&mut self, k: [usize](../primitive.usize.html))[src]
🔬 This is a nightly-only experimental API. (slice_rotate #41891)
Rotates the slice in-place such that the first self.len() - kelements 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.
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.
Takes linear (in self.len()) time.
#![feature(slice_rotate)]
let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; a.rotate_right(2); assert_eq!(a, ['e', 'f', 'a', 'b', 'c', 'd']);Run
Rotate a subslice:
#![feature(slice_rotate)]
let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; a[1..5].rotate_right(1); assert_eq!(a, ['a', 'e', 'b', 'c', 'd', 'f']);Run
`pub fn clone_from_slice(&mut self, src: &[T]) where
T: Clone, `
1.7.0
Copies the elements from src into self.
The length of src must be the same as self.
If src implements Copy, it can be more performant to usecopy_from_slice.
This function will panic if the two slices have different lengths.
Cloning two elements from a slice into another:
let src = [1, 2, 3, 4]; let mut dst = [0, 0];
dst.clone_from_slice(&src[2..]);
assert_eq!(src, [1, 2, 3, 4]); assert_eq!(dst, [3, 4]);Run
Rust enforces that there can only be one mutable reference with no immutable references to a particular piece of data in a particular scope. Because of this, attempting to use clone_from_slice on a single slice will result in a compile failure:
ⓘThis example deliberately fails to compile
let mut slice = [1, 2, 3, 4, 5];
slice[..2].clone_from_slice(&slice[3..]); Run
To work around this, we can use split_at_mut to create two distinct sub-slices from a slice:
let mut slice = [1, 2, 3, 4, 5];
{ let (left, right) = slice.split_at_mut(2); left.clone_from_slice(&right[1..]); }
assert_eq!(slice, [4, 5, 3, 4, 5]);Run
`pub fn copy_from_slice(&mut self, src: &[T]) where
T: Copy, `
1.9.0
Copies all elements from src into self, using a memcpy.
The length of src must be the same as self.
If src does not implement Copy, use clone_from_slice.
This function will panic if the two slices have different lengths.
Copying two elements from a slice into another:
let src = [1, 2, 3, 4]; let mut dst = [0, 0];
dst.copy_from_slice(&src[2..]);
assert_eq!(src, [1, 2, 3, 4]); assert_eq!(dst, [3, 4]);Run
Rust enforces that there can only be one mutable reference with no immutable references to a particular piece of data in a particular scope. Because of this, attempting to use copy_from_slice on a single slice will result in a compile failure:
ⓘThis example deliberately fails to compile
let mut slice = [1, 2, 3, 4, 5];
slice[..2].copy_from_slice(&slice[3..]); Run
To work around this, we can use split_at_mut to create two distinct sub-slices from a slice:
let mut slice = [1, 2, 3, 4, 5];
{ let (left, right) = slice.split_at_mut(2); left.copy_from_slice(&right[1..]); }
assert_eq!(slice, [4, 5, 3, 4, 5]);Run
pub fn [swap_with_slice](#method.swap%5Fwith%5Fslice)(&mut self, other: [&mut [T]](../primitive.slice.html))[src]
🔬 This is a nightly-only experimental API. (swap_with_slice #44030)
Swaps all elements in self with those in other.
The length of other must be the same as self.
This function will panic if the two slices have different lengths.
Swapping two elements across slices:
#![feature(swap_with_slice)]
let mut slice1 = [0, 0]; let mut slice2 = [1, 2, 3, 4];
slice1.swap_with_slice(&mut slice2[2..]);
assert_eq!(slice1, [3, 4]); assert_eq!(slice2, [1, 2, 0, 0]);Run
Rust enforces that there can only be one mutable reference to a particular piece of data in a particular scope. Because of this, attempting to use swap_with_slice on a single slice will result in a compile failure:
ⓘThis example deliberately fails to compile
#![feature(swap_with_slice)]
let mut slice = [1, 2, 3, 4, 5]; slice[..2].swap_with_slice(&mut slice[3..]); Run
To work around this, we can use split_at_mut to create two distinct mutable sub-slices from a slice:
#![feature(swap_with_slice)]
let mut slice = [1, 2, 3, 4, 5];
{ let (left, right) = slice.split_at_mut(2); left.swap_with_slice(&mut right[1..]); }
assert_eq!(slice, [4, 5, 3, 1, 2]);Run
pub fn [to_vec](#method.to%5Fvec)(&self) -> [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T> where T: [Clone](../../std/clone/trait.Clone.html "trait std::clone::Clone"), [src]
Copies self into a new Vec.
let s = [10, 40, 30]; let x = s.to_vec(); Run
pub fn [is_ascii](#method.is%5Fascii)(&self) -> [bool](../primitive.bool.html)
1.23.0
Checks if all bytes in this slice are within the ASCII range.
pub fn [to_ascii_uppercase](#method.to%5Fascii%5Fuppercase)(&self) -> [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<[u8](../primitive.u8.html)>
1.23.0
Returns a vector containing a copy of this slice where each byte is mapped to its ASCII upper case equivalent.
ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', but non-ASCII letters are unchanged.
To uppercase the value in-place, use make_ascii_uppercase.
pub fn [to_ascii_lowercase](#method.to%5Fascii%5Flowercase)(&self) -> [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<[u8](../primitive.u8.html)>
1.23.0
Returns a vector containing a copy of this slice where each byte is mapped to its ASCII lower case equivalent.
ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', but non-ASCII letters are unchanged.
To lowercase the value in-place, use make_ascii_lowercase.
pub fn [eq_ignore_ascii_case](#method.eq%5Fignore%5Fascii%5Fcase)(&self, other: [&[](../primitive.slice.html)[u8](../primitive.u8.html)[]](../primitive.slice.html)) -> [bool](../primitive.bool.html)
1.23.0
Checks that two slices are an ASCII case-insensitive match.
Same as to_ascii_lowercase(a) == to_ascii_lowercase(b), but without allocating and copying temporaries.
pub fn [make_ascii_uppercase](#method.make%5Fascii%5Fuppercase)(&mut self)
1.23.0
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, useto_ascii_uppercase.
pub fn [make_ascii_lowercase](#method.make%5Fascii%5Flowercase)(&mut self)
1.23.0
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, useto_ascii_lowercase.
`impl<'a, T> From<Cow<'a, T[]>> for Vec where
T[]: ToOwned,
<T[] as ToOwned>::Owned == Vec, `
1.14.0
`impl<'a, T> From<&'a [T]> for Vec where
`impl From<Vec> for BinaryHeap where
T: Ord, `
1.5.0
impl<T> [From](../../std/convert/trait.From.html "trait std::convert::From")<[Box](../../std/boxed/struct.Box.html "struct std::boxed::Box")<[[](../primitive.slice.html)T[]](../primitive.slice.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>
1.18.0
`impl<'a, T> From<Vec> for Cow<'a, T[]> where
T: Clone, `
1.8.0
impl<T> [From](../../std/convert/trait.From.html "trait std::convert::From")<[VecDeque](../../std/collections/vec%5Fdeque/struct.VecDeque.html "struct std::collections::vec_deque::VecDeque")<T>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>
1.10.0
impl<T> [From](../../std/convert/trait.From.html "trait std::convert::From")<[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>> for [Box](../../std/boxed/struct.Box.html "struct std::boxed::Box")<[[](../primitive.slice.html)T[]](../primitive.slice.html)>
1.20.0
impl [From](../../std/convert/trait.From.html "trait std::convert::From")<[String](../../std/string/struct.String.html "struct std:🧵:String")> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<[u8](../primitive.u8.html)>
1.14.0
impl<T> [From](../../std/convert/trait.From.html "trait std::convert::From")<[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>> for [Arc](../../std/sync/struct.Arc.html "struct std::sync::Arc")<[[](../primitive.slice.html)T[]](../primitive.slice.html)>
1.21.0
impl<T> [From](../../std/convert/trait.From.html "trait std::convert::From")<[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>> for [Rc](../../std/rc/struct.Rc.html "struct std::rc::Rc")<[[](../primitive.slice.html)T[]](../primitive.slice.html)>
1.21.0
impl<'a> [From](../../std/convert/trait.From.html "trait std::convert::From")<&'a [str](../primitive.str.html)> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<[u8](../primitive.u8.html)>[src]
impl<T> [From](../../std/convert/trait.From.html "trait std::convert::From")<[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>> for [VecDeque](../../std/collections/vec%5Fdeque/struct.VecDeque.html "struct std::collections::vec_deque::VecDeque")<T>
1.10.0
impl<T> [From](../../std/convert/trait.From.html "trait std::convert::From")<[BinaryHeap](../../std/collections/binary%5Fheap/struct.BinaryHeap.html "struct std::collections::binary_heap::BinaryHeap")<T>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>
1.5.0
`impl<'a, T> From<&'a mut [T]> for Vec where
T: Clone, `
1.19.0
impl<T> [IndexMut](../../std/ops/trait.IndexMut.html "trait std::ops::IndexMut")<[Range](../../std/ops/struct.Range.html "struct std::ops::Range")<[usize](../primitive.usize.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [IndexMut](../../std/ops/trait.IndexMut.html "trait std::ops::IndexMut")<[RangeFull](../../std/ops/struct.RangeFull.html "struct std::ops::RangeFull")> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [IndexMut](../../std/ops/trait.IndexMut.html "trait std::ops::IndexMut")<[RangeTo](../../std/ops/struct.RangeTo.html "struct std::ops::RangeTo")<[usize](../primitive.usize.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [IndexMut](../../std/ops/trait.IndexMut.html "trait std::ops::IndexMut")<[RangeToInclusive](../../std/ops/struct.RangeToInclusive.html "struct std::ops::RangeToInclusive")<[usize](../primitive.usize.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [IndexMut](../../std/ops/trait.IndexMut.html "trait std::ops::IndexMut")<[RangeInclusive](../../std/ops/struct.RangeInclusive.html "struct std::ops::RangeInclusive")<[usize](../primitive.usize.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [IndexMut](../../std/ops/trait.IndexMut.html "trait std::ops::IndexMut")<[usize](../primitive.usize.html)> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [IndexMut](../../std/ops/trait.IndexMut.html "trait std::ops::IndexMut")<[RangeFrom](../../std/ops/struct.RangeFrom.html "struct std::ops::RangeFrom")<[usize](../primitive.usize.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [Borrow](../../std/borrow/trait.Borrow.html "trait std::borrow::Borrow")<[[](../primitive.slice.html)T[]](../primitive.slice.html)> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [BorrowMut](../../std/borrow/trait.BorrowMut.html "trait std::borrow::BorrowMut")<[[](../primitive.slice.html)T[]](../primitive.slice.html)> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
`impl Ord for Vec where
Implements ordering of vectors, lexicographically.
fn [cmp](../../std/cmp/trait.Ord.html#tymethod.cmp)(&self, other: &[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>) -> [Ordering](../../std/cmp/enum.Ordering.html "enum std::cmp::Ordering")[src]
This method returns an Ordering between self and other. Read more
fn [max](../../std/cmp/trait.Ord.html#method.max)(self, other: Self) -> Self
1.21.0
Compares and returns the maximum of two values. Read more
fn [min](../../std/cmp/trait.Ord.html#method.min)(self, other: Self) -> Self
1.21.0
Compares and returns the minimum of two values. Read more
`impl Clone for Vec where
impl<T> [DerefMut](../../std/ops/trait.DerefMut.html "trait std::ops::DerefMut") for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
`impl<'a, T> Extend<&'a T> for Vec where
T: 'a + Copy, `
1.2.0
Extend implementation that copies elements out of references before pushing them onto the Vec.
This implementation is specialized for slice iterators, where it uses copy_from_slice to append the entire slice at once.
impl<T> [Extend](../../std/iter/trait.Extend.html "trait std::iter::Extend")<T> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
`impl Hash for Vec where
impl<T> [AsMut](../../std/convert/trait.AsMut.html "trait std::convert::AsMut")<[[](../primitive.slice.html)T[]](../primitive.slice.html)> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>
1.5.0
impl<T> [AsMut](../../std/convert/trait.AsMut.html "trait std::convert::AsMut")<[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>
1.5.0
impl<T> [Index](../../std/ops/trait.Index.html "trait std::ops::Index")<[RangeTo](../../std/ops/struct.RangeTo.html "struct std::ops::RangeTo")<[usize](../primitive.usize.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [Index](../../std/ops/trait.Index.html "trait std::ops::Index")<[usize](../primitive.usize.html)> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
type [Output](../../std/ops/trait.Index.html#associatedtype.Output) = T
The returned type after indexing.
fn [index](../../std/ops/trait.Index.html#tymethod.index)(&self, index: [usize](../primitive.usize.html)) -> [&](../primitive.reference.html)T[src]
Performs the indexing (container[index]) operation.
impl<T> [Index](../../std/ops/trait.Index.html "trait std::ops::Index")<[RangeFull](../../std/ops/struct.RangeFull.html "struct std::ops::RangeFull")> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [Index](../../std/ops/trait.Index.html "trait std::ops::Index")<[RangeToInclusive](../../std/ops/struct.RangeToInclusive.html "struct std::ops::RangeToInclusive")<[usize](../primitive.usize.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [Index](../../std/ops/trait.Index.html "trait std::ops::Index")<[Range](../../std/ops/struct.Range.html "struct std::ops::Range")<[usize](../primitive.usize.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [Index](../../std/ops/trait.Index.html "trait std::ops::Index")<[RangeInclusive](../../std/ops/struct.RangeInclusive.html "struct std::ops::RangeInclusive")<[usize](../primitive.usize.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [Index](../../std/ops/trait.Index.html "trait std::ops::Index")<[RangeFrom](../../std/ops/struct.RangeFrom.html "struct std::ops::RangeFrom")<[usize](../primitive.usize.html)>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
`impl<'a, 'b, A, B> PartialEq<&'b B[; 9]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 5]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 0]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 14]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 3]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 26]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 10]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 25]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 32]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 31]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 29]> for Vec where
`impl<'a, 'b, A, B> PartialEq<Vec> for VecDeque where
A: PartialEq, `
1.17.0
fn [eq](../../std/cmp/trait.PartialEq.html#tymethod.eq)(&self, other: &[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<B>) -> [bool](../primitive.bool.html)[src]
This method tests for self and other values to be equal, and is used by ==. Read more
fn [ne](../../std/cmp/trait.PartialEq.html#method.ne)(&self, other: [&](../primitive.reference.html)Rhs) -> [bool](../primitive.bool.html)[src]
This method tests for !=.
`impl<'a, 'b, A, B> PartialEq<B[; 4]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 13]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 5]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b [B]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 16]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 21]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 12]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 23]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 16]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 26]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 30]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 1]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 19]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 22]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 0]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 24]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 6]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b mut [B]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 12]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 14]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 15]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 30]> for Vec where
`impl<'a, 'b, A, B> PartialEq<Vec> for Vec where
fn [eq](../../std/cmp/trait.PartialEq.html#tymethod.eq)(&self, other: &[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<B>) -> [bool](../primitive.bool.html)[src]
This method tests for self and other values to be equal, and is used by ==. Read more
fn [ne](../../std/cmp/trait.PartialEq.html#method.ne)(&self, other: &[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<B>) -> [bool](../primitive.bool.html)[src]
This method tests for !=.
`impl<'a, 'b, A, B> PartialEq<&'b B[; 4]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 18]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 21]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 28]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 17]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 29]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 17]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 15]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 13]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 7]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 25]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 8]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 3]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 8]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 22]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 11]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 18]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 7]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 23]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 24]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 20]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 19]> for Vec where
`impl<'a, 'b, A, B> PartialEq<Vec> for Cow<'a, A[]> where
fn [eq](../../std/cmp/trait.PartialEq.html#tymethod.eq)(&self, other: &[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<B>) -> [bool](../primitive.bool.html)[src]
This method tests for self and other values to be equal, and is used by ==. Read more
fn [ne](../../std/cmp/trait.PartialEq.html#method.ne)(&self, other: &[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<B>) -> [bool](../primitive.bool.html)[src]
This method tests for !=.
`impl<'a, 'b, A, B> PartialEq<&'b B[; 20]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 2]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 6]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 27]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 2]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 10]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 32]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 31]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 11]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 9]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 28]> for Vec where
`impl<'a, 'b, A, B> PartialEq<B[; 27]> for Vec where
`impl<'a, 'b, A, B> PartialEq<&'b B[; 1]> for Vec where
`impl Eq for Vec where
impl<T> [AsRef](../../std/convert/trait.AsRef.html "trait std::convert::AsRef")<[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [AsRef](../../std/convert/trait.AsRef.html "trait std::convert::AsRef")<[[](../primitive.slice.html)T[]](../primitive.slice.html)> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [Default](../../std/default/trait.Default.html "trait std::default::Default") for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [FromIterator](../../std/iter/trait.FromIterator.html "trait std::iter::FromIterator")<T> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl<T> [IntoIterator](../../std/iter/trait.IntoIterator.html "trait std::iter::IntoIterator") for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
type [Item](../../std/iter/trait.IntoIterator.html#associatedtype.Item) = T
The type of the elements being iterated over.
type [IntoIter](../../std/iter/trait.IntoIterator.html#associatedtype.IntoIter) = [IntoIter](../../std/vec/struct.IntoIter.html "struct std::vec::IntoIter")<T>
Which kind of iterator are we turning this into?
fn [into_iter](../../std/iter/trait.IntoIterator.html#tymethod.into%5Fiter)(self) -> [IntoIter](../../std/vec/struct.IntoIter.html "struct std::vec::IntoIter")<T>[src]
Creates a consuming iterator, that is, one that moves each value out of the vector (from start to end). The vector cannot be used after calling this.
let v = vec!["a".to_string(), "b".to_string()]; for s in v.into_iter() {
println!("{}", s);}Run
impl<'a, T> [IntoIterator](../../std/iter/trait.IntoIterator.html "trait std::iter::IntoIterator") for &'a [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
type [Item](../../std/iter/trait.IntoIterator.html#associatedtype.Item) = [&'a ](../primitive.reference.html)T
The type of the elements being iterated over.
type [IntoIter](../../std/iter/trait.IntoIterator.html#associatedtype.IntoIter) = [Iter](../../std/slice/struct.Iter.html "struct std::slice::Iter")<'a, T>
Which kind of iterator are we turning this into?
ⓘImportant traits for Iter<'a, T>
fn [into_iter](../../std/iter/trait.IntoIterator.html#tymethod.into%5Fiter)(self) -> [Iter](../../std/slice/struct.Iter.html "struct std::slice::Iter")<'a, T>[src]
Creates an iterator from a value. Read more
impl<'a, T> [IntoIterator](../../std/iter/trait.IntoIterator.html "trait std::iter::IntoIterator") for &'a mut [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
`impl Debug for Vec where
impl<T> [Deref](../../std/ops/trait.Deref.html "trait std::ops::Deref") for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
`impl PartialOrd<Vec> for Vec where
T: PartialOrd, `[src]
Implements comparison of vectors, lexicographically.
fn [partial_cmp](../../std/cmp/trait.PartialOrd.html#tymethod.partial%5Fcmp)(&self, other: &[Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>) -> [Option](../../std/option/enum.Option.html "enum std::option::Option")<[Ordering](../../std/cmp/enum.Ordering.html "enum std::cmp::Ordering")>[src]
This method returns an ordering between self and other values if one exists. Read more
fn [lt](../../std/cmp/trait.PartialOrd.html#method.lt)(&self, other: [&](../primitive.reference.html)Rhs) -> [bool](../primitive.bool.html)[src]
This method tests less than (for self and other) and is used by the < operator. Read more
fn [le](../../std/cmp/trait.PartialOrd.html#method.le)(&self, other: [&](../primitive.reference.html)Rhs) -> [bool](../primitive.bool.html)[src]
This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
fn [gt](../../std/cmp/trait.PartialOrd.html#method.gt)(&self, other: [&](../primitive.reference.html)Rhs) -> [bool](../primitive.bool.html)[src]
This method tests greater than (for self and other) and is used by the > operator. Read more
fn [ge](../../std/cmp/trait.PartialOrd.html#method.ge)(&self, other: [&](../primitive.reference.html)Rhs) -> [bool](../primitive.bool.html)[src]
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
impl<T> [Drop](../../std/ops/trait.Drop.html "trait std::ops::Drop") for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<T>[src]
impl [From](../../std/convert/trait.From.html "trait std::convert::From")<[CString](../../std/ffi/struct.CString.html "struct std::ffi::CString")> for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<[u8](../primitive.u8.html)>
1.7.0
impl [Write](../../std/io/trait.Write.html "trait std::io::Write") for [Vec](../../std/vec/struct.Vec.html "struct std::vec::Vec")<[u8](../primitive.u8.html)>[src]
Write is implemented for Vec<u8> by appending to the vector. The vector will grow as needed.