Trait nom::lib::std::prelude::v1::rust_2018::IntoIterator 1.0.0[−][src]
pub trait IntoIterator {
type Item;
type IntoIter: Iterator;
#[lang = "into_iter"]
pub fn into_iter(self) -> Self::IntoIter;
}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
type Item[src]
The type of the elements being iterated over.
type IntoIter: Iterator[src]
Which kind of iterator are we turning this into?
Required methods
#[lang = "into_iter"]pub fn into_iter(self) -> Self::IntoIter[src]
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());
Implementors
impl<'a, T> IntoIterator for &'a Option<T>1.4.0[src]
impl<'a, T> IntoIterator for &'a [T][src]
impl<'a, T> IntoIterator for &'a mut Option<T>1.4.0[src]
impl<'a, T> IntoIterator for &'a mut [T][src]
impl<'a, T, E> IntoIterator for &'a Result<T, E>1.4.0[src]
impl<'a, T, E> IntoIterator for &'a mut Result<T, E>1.4.0[src]
impl<'a, T, const N: usize> IntoIterator for &'a [T; N][src]
impl<'a, T, const N: usize> IntoIterator for &'a mut [T; N][src]
impl<I> IntoIterator for I where
I: Iterator, [src]
I: Iterator,
impl<T> IntoIterator for Option<T>[src]
type Item = T
type IntoIter = IntoIter<T>
pub fn into_iter(self) -> IntoIter<T>ⓘ[src]
Returns a consuming iterator over the possibly contained value.
Examples
let x = Some("string"); let v: Vec<&str> = x.into_iter().collect(); assert_eq!(v, ["string"]); let x = None; let v: Vec<&str> = x.into_iter().collect(); assert!(v.is_empty());
impl<T, E> IntoIterator for Result<T, E>[src]
type Item = T
type IntoIter = IntoIter<T>
pub fn into_iter(self) -> IntoIter<T>ⓘ[src]
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, []);