Trait otter::prelude::iter::IntoIterator 1.0.0[−][src]
pub trait IntoIterator { type Item; type IntoIter: Iterator; fn into_iter(self) -> Self::IntoIter; }
Expand description
Conversion into an Iterator
.
By implementing IntoIterator
for a type, you define how it will be
converted to an iterator. This is common for types which describe a
collection of some kind.
One benefit of implementing IntoIterator
is that your type will work
with Rust’s for
loop syntax.
See also: FromIterator
.
Examples
Basic usage:
let v = vec![1, 2, 3]; let mut iter = v.into_iter(); assert_eq!(Some(1), iter.next()); assert_eq!(Some(2), iter.next()); assert_eq!(Some(3), iter.next()); assert_eq!(None, iter.next());
Implementing IntoIterator
for your type:
// A sample collection, that's just a wrapper over Vec<T> #[derive(Debug)] struct MyCollection(Vec<i32>); // Let's give it some methods so we can create one and add things // to it. impl MyCollection { fn new() -> MyCollection { MyCollection(Vec::new()) } fn add(&mut self, elem: i32) { self.0.push(elem); } } // and we'll implement IntoIterator impl IntoIterator for MyCollection { type Item = i32; type IntoIter = std::vec::IntoIter<Self::Item>; fn into_iter(self) -> Self::IntoIter { self.0.into_iter() } } // Now we can make a new collection... let mut c = MyCollection::new(); // ... add some stuff to it ... c.add(0); c.add(1); c.add(2); // ... and then turn it into an Iterator: for (i, n) in c.into_iter().enumerate() { assert_eq!(i as i32, n); }
It is common to use IntoIterator
as a trait bound. This allows
the input collection type to change, so long as it is still an
iterator. Additional bounds can be specified by restricting on
Item
:
fn collect_as_strings<T>(collection: T) -> Vec<String> where T: IntoIterator, T::Item: std::fmt::Debug, { collection .into_iter() .map(|item| format!("{:?}", item)) .collect() }
Associated Types
Required methods
Creates an iterator from a value.
See the module-level documentation for more.
Examples
Basic usage:
let v = vec![1, 2, 3]; let mut iter = v.into_iter(); assert_eq!(Some(1), iter.next()); assert_eq!(Some(2), iter.next()); assert_eq!(Some(3), iter.next()); assert_eq!(None, iter.next());
Implementations on Foreign Types
Creates a consuming iterator, that is, one that moves each value out of
the array (from start to end). The array cannot be used after calling
this unless T
implements Copy
, so the whole array is copied.
Arrays have special behavior when calling .into_iter()
prior to the
2021 edition – see the array Editions section for more information.
type Item = T
Returns a consuming iterator over the possibly contained value.
The iterator yields one value if the result is Result::Ok
, otherwise none.
Examples
Basic usage:
let x: Result<u32, &str> = Ok(5); let v: Vec<u32> = x.into_iter().collect(); assert_eq!(v, [5]); let x: Result<u32, &str> = Err("nothing!"); let v: Vec<u32> = x.into_iter().collect(); assert_eq!(v, []);
type Item = T
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.
Examples
let v = vec!["a".to_string(), "b".to_string()]; for s in v.into_iter() { // s has type String, not &String println!("{}", s); }
type Item = T
Creates a consuming iterator, that is, one that moves each value out of the binary heap in arbitrary order. The binary heap cannot be used after calling this.
Examples
Basic usage:
use std::collections::BinaryHeap; let heap = BinaryHeap::from(vec![1, 2, 3, 4]); // Print 1, 2, 3, 4 in arbitrary order for x in heap.into_iter() { // x has type i32, not &i32 println!("{}", x); }
type Item = T
impl<T, N> IntoIterator for GenericArray<T, N> where
N: ArrayLength<T>,
impl<T, N> IntoIterator for GenericArray<T, N> where
N: ArrayLength<T>,
type Item = T
type IntoIter = GenericArrayIter<T, N>
pub fn into_iter(self) -> <GenericArray<T, N> as IntoIterator>::IntoIter
impl<'a, T, N> IntoIterator for &'a GenericArray<T, N> where
T: 'a,
N: ArrayLength<T>,
impl<'a, T, N> IntoIterator for &'a GenericArray<T, N> where
T: 'a,
N: ArrayLength<T>,
impl<'a, T, N> IntoIterator for &'a mut GenericArray<T, N> where
T: 'a,
N: ArrayLength<T>,
impl<'a, T, N> IntoIterator for &'a mut GenericArray<T, N> where
T: 'a,
N: ArrayLength<T>,
type IntoIter = SetMatchesIntoIter
type IntoIter = SetMatchesIntoIter
type IntoIter = SetMatchesIter<'a>
type IntoIter = SetMatchesIter<'a>
impl<'a> IntoIterator for &'a Utf8Sequence
impl<'a> IntoIterator for &'a Utf8Sequence
impl<T> IntoIterator for Slab<T>
impl<T> IntoIterator for Slab<T>
impl<'a, T> IntoIterator for &'a mut Slab<T>
impl<'a, T> IntoIterator for &'a mut Slab<T>
impl<'a, T> IntoIterator for &'a Slab<T>
impl<'a, T> IntoIterator for &'a Slab<T>
impl IntoIterator for WalkDir
impl IntoIterator for WalkDir
type Item = A
Creates a owning iterator, that is, one that takes ownership of the
Dir
. The Dir
cannot be used after calling this. This can be useful
when you have a function that both creates a Dir
instance and returns
an Iterator
.
Example:
use nix::{dir::Dir, fcntl::OFlag, sys::stat::Mode}; use std::{iter::Iterator, string::String}; fn ls_upper(dirname: &str) -> impl Iterator<Item=String> { let d = Dir::open(dirname, OFlag::O_DIRECTORY, Mode::S_IXUSR).unwrap(); d.into_iter().map(|x| x.unwrap().file_name().as_ref().to_string_lossy().to_ascii_uppercase()) }
type IntoIter = OwningIter
impl<'a, A> IntoIterator for &'a SmallVec<A> where
A: Array,
impl<'a, A> IntoIterator for &'a SmallVec<A> where
A: Array,
impl<'a, A> IntoIterator for &'a mut SmallVec<A> where
A: Array,
impl<'a, A> IntoIterator for &'a mut SmallVec<A> where
A: Array,
impl<A> IntoIterator for SmallVec<A> where
A: Array,
impl<A> IntoIterator for SmallVec<A> where
A: Array,
type IntoIter = IntoIter<A>
type Item = <A as Array>::Item
pub fn into_iter(self) -> <SmallVec<A> as IntoIterator>::IntoIter
pub fn into_iter(self) -> IndexVecIntoIterⓘNotable traits for IndexVecIntoIter
impl Iterator for IndexVecIntoIter type Item = usize;
[src]
pub fn into_iter(self) -> IndexVecIntoIterⓘNotable traits for IndexVecIntoIter
impl Iterator for IndexVecIntoIter type Item = usize;
[src]Convert into an iterator over the indices as a sequence of usize
values
type IntoIter = IndexVecIntoIter
impl<'a, A> IntoIterator for &'a mut ArrayVec<A> where
A: Array,
impl<'a, A> IntoIterator for &'a mut ArrayVec<A> where
A: Array,
impl<'s, T> IntoIterator for SliceVec<'s, T>
impl<'s, T> IntoIterator for SliceVec<'s, T>
impl<'a, A> IntoIterator for &'a TinyVec<A> where
A: Array,
impl<'a, A> IntoIterator for &'a TinyVec<A> where
A: Array,
impl<'a, A> IntoIterator for &'a ArrayVec<A> where
A: Array,
impl<'a, A> IntoIterator for &'a ArrayVec<A> where
A: Array,
impl<A> IntoIterator for ArrayVec<A> where
A: Array,
impl<A> IntoIterator for ArrayVec<A> where
A: Array,
type Item = <A as Array>::Item
type IntoIter = ArrayVecIterator<A>
#[must_use]pub fn into_iter(self) -> <ArrayVec<A> as IntoIterator>::IntoIter
impl<A> IntoIterator for TinyVec<A> where
A: Array,
impl<A> IntoIterator for TinyVec<A> where
A: Array,
type Item = <A as Array>::Item
type IntoIter = TinyVecIterator<A>
#[must_use]pub fn into_iter(self) -> <TinyVec<A> as IntoIterator>::IntoIter
impl<'a, A> IntoIterator for &'a mut TinyVec<A> where
A: Array,
impl<'a, A> IntoIterator for &'a mut TinyVec<A> where
A: Array,
impl IntoIterator for CharRange
impl IntoIterator for CharRange
impl<'a, T> IntoIterator for &'a ThreadLocal<T> where
T: Send + Sync,
impl<'a, T> IntoIterator for &'a ThreadLocal<T> where
T: Send + Sync,
impl<'a, T> IntoIterator for &'a mut CachedThreadLocal<T> where
T: 'a + Send,
impl<'a, T> IntoIterator for &'a mut CachedThreadLocal<T> where
T: 'a + Send,
impl<T> IntoIterator for CachedThreadLocal<T> where
T: Send,
impl<T> IntoIterator for CachedThreadLocal<T> where
T: Send,
impl<'a, T> IntoIterator for &'a mut ThreadLocal<T> where
T: Send,
impl<'a, T> IntoIterator for &'a mut ThreadLocal<T> where
T: Send,
impl<T> IntoIterator for ThreadLocal<T> where
T: Send,
impl<T> IntoIterator for ThreadLocal<T> where
T: Send,
impl IntoIterator for CharRange
impl IntoIterator for CharRange
Implementors
Return an iterator from &RcIter<I>
(by simply cloning it).
impl<'a, K, V, S> IntoIterator for &'a SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher,
[src]
impl<'a, K, V, S> IntoIterator for &'a SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher,
[src]impl<'a, K, V, S> IntoIterator for &'a mut SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher,
[src]
impl<'a, K, V, S> IntoIterator for &'a mut SparseSecondaryMap<K, V, S> where
K: Key,
S: BuildHasher,
[src]impl<'a, T, const CAP: usize> IntoIterator for &'a otter::prelude::ArrayVec<T, CAP> where
T: 'a,
[src]
impl<'a, T, const CAP: usize> IntoIterator for &'a otter::prelude::ArrayVec<T, CAP> where
T: 'a,
[src]Iterate the ArrayVec
with references to each element.
use arrayvec::ArrayVec; let array = ArrayVec::from([1, 2, 3]); for elt in &array { // ... }
impl<'a, T, const CAP: usize> IntoIterator for &'a mut otter::prelude::ArrayVec<T, CAP> where
T: 'a,
[src]
impl<'a, T, const CAP: usize> IntoIterator for &'a mut otter::prelude::ArrayVec<T, CAP> where
T: 'a,
[src]Iterate the ArrayVec
with mutable references to each element.
use arrayvec::ArrayVec; let mut array = ArrayVec::from([1, 2, 3]); for elt in &mut array { // ... }
Creates a consuming iterator, that is, one that moves each key-value pair out of the map in arbitrary order. The map cannot be used after calling this.
Examples
use std::collections::HashMap; let mut map = HashMap::new(); map.insert("a", 1); map.insert("b", 2); map.insert("c", 3); // Not possible with .iter() let vec: Vec<(&str, i32)> = map.into_iter().collect();
Creates a consuming iterator, that is, one that moves each value out of the set in arbitrary order. The set cannot be used after calling this.
Examples
use std::collections::HashSet; let mut set = HashSet::new(); set.insert("a".to_string()); set.insert("b".to_string()); // Not possible to collect to a Vec<String> with a regular `.iter()`. let v: Vec<String> = set.into_iter().collect(); // Will print in an arbitrary order. for x in &v { println!("{}", x); }
type Item = T
Iterate the ArrayVec
with each element by value.
The vector is consumed by this operation.
use arrayvec::ArrayVec; for elt in ArrayVec::from([1, 2, 3]) { // ... }