Trait otter::prelude::iter::Extend 1.0.0[−][src]
pub trait Extend<A> { fn extend<T>(&mut self, iter: T)
where
T: IntoIterator<Item = A>; fn extend_one(&mut self, item: A) { ... } fn extend_reserve(&mut self, additional: usize) { ... } }
Expand description
Extend a collection with the contents of an iterator.
Iterators produce a series of values, and collections can also be thought
of as a series of values. The Extend
trait bridges this gap, allowing you
to extend a collection by including the contents of that iterator. When
extending a collection with an already existing key, that entry is updated
or, in the case of collections that permit multiple entries with equal
keys, that entry is inserted.
Examples
Basic usage:
// You can extend a String with some chars: let mut message = String::from("The first three letters are: "); message.extend(&['a', 'b', 'c']); assert_eq!("abc", &message[29..32]);
Implementing Extend
:
// 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); } } // since MyCollection has a list of i32s, we implement Extend for i32 impl Extend<i32> for MyCollection { // This is a bit simpler with the concrete type signature: we can call // extend on anything which can be turned into an Iterator which gives // us i32s. Because we need i32s to put into MyCollection. fn extend<T: IntoIterator<Item=i32>>(&mut self, iter: T) { // The implementation is very straightforward: loop through the // iterator, and add() each element to ourselves. for elem in iter { self.add(elem); } } } let mut c = MyCollection::new(); c.add(5); c.add(6); c.add(7); // let's extend our collection with three more numbers c.extend(vec![1, 2, 3]); // we've added these elements onto the end assert_eq!("MyCollection([5, 6, 7, 1, 2, 3])", format!("{:?}", c));
Required methods
fn extend<T>(&mut self, iter: T) where
T: IntoIterator<Item = A>,
[src]
fn extend<T>(&mut self, iter: T) where
T: IntoIterator<Item = A>,
[src]Extends a collection with the contents of an iterator.
As this is the only required method for this trait, the trait-level docs contain more details.
Examples
Basic usage:
// You can extend a String with some chars: let mut message = String::from("abc"); message.extend(['d', 'e', 'f'].iter()); assert_eq!("abcdef", &message);
Provided methods
fn extend_one(&mut self, item: A)
[src]
fn extend_one(&mut self, item: A)
[src]extend_one
)Extends a collection with exactly one element.
fn extend_reserve(&mut self, additional: usize)
[src]
fn extend_reserve(&mut self, additional: usize)
[src]extend_one
)Reserves capacity in a collection for the given number of additional elements.
The default implementation does nothing.
Implementations on Foreign Types
extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)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.
extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)impl Extend<Op> for Op
impl Extend<Op> for Op
pub fn extend<T>(&mut self, iterator: T) where
T: IntoIterator<Item = Op>,
impl Extend<EventMask> for EventMask
impl Extend<EventMask> for EventMask
pub fn extend<T>(&mut self, iterator: T) where
T: IntoIterator<Item = EventMask>,
impl Extend<WatchMask> for WatchMask
impl Extend<WatchMask> for WatchMask
pub fn extend<T>(&mut self, iterator: T) where
T: IntoIterator<Item = WatchMask>,
impl<A> Extend<<A as Array>::Item> for SmallVec<A> where
A: Array,
impl<A> Extend<<A as Array>::Item> for SmallVec<A> where
A: Array,
pub fn extend<I>(&mut self, iterable: I) where
I: IntoIterator<Item = <A as Array>::Item>,
impl<'s, T> Extend<T> for SliceVec<'s, T>
impl<'s, T> Extend<T> for SliceVec<'s, T>
pub fn extend<I>(&mut self, iter: I) where
I: IntoIterator<Item = T>,
impl<A> Extend<<A as Array>::Item> for ArrayVec<A> where
A: Array,
impl<A> Extend<<A as Array>::Item> for ArrayVec<A> where
A: Array,
pub fn extend<T>(&mut self, iter: T) where
T: IntoIterator<Item = <A as Array>::Item>,
impl<A> Extend<<A as Array>::Item> for TinyVec<A> where
A: Array,
impl<A> Extend<<A as Array>::Item> for TinyVec<A> where
A: Array,
pub fn extend<T>(&mut self, iter: T) where
T: IntoIterator<Item = <A as Array>::Item>,
impl Extend<Transformations> for Transformations
impl Extend<Transformations> for Transformations
pub fn extend<T>(&mut self, iterator: T) where
T: IntoIterator<Item = Transformations>,
impl Extend<FileType> for FileType
impl Extend<FileType> for FileType
pub fn extend<T>(&mut self, iterator: T) where
T: IntoIterator<Item = FileType>,
Implementors
extend_one
)extend_one
)impl<'a, K, V, S> Extend<(K, &'a V)> for SparseSecondaryMap<K, V, S> where
K: Key,
V: 'a + Copy,
S: BuildHasher,
[src]
impl<'a, K, V, S> Extend<(K, &'a V)> for SparseSecondaryMap<K, V, S> where
K: Key,
V: 'a + Copy,
S: BuildHasher,
[src]extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)Inserts all new key-values from the iterator and replaces values with existing keys with new values returned from the iterator.
extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)extend_one
)Extend the ArrayVec
with an iterator.
Panics if extending the vector exceeds its capacity.
Extend the ArrayVec
with an iterator.
Panics if extending the vector exceeds its capacity.