Struct `Drain`

struct Drain<'a, T: 'a, A: Allocator + 'a = crate::alloc::Global> { ... }

A draining iterator for Vec<T>.

This struct is created by Vec::drain. See its documentation for more.

Example

let mut v = vec![0, 1, 2];
let iter: std::vec::Drain<'_, _> = v.drain(..);

Implementations

`impl<'a, T, A: Allocator> Drain<'a, T, A>`

fn as_slice(self: &Self) -> &[T]

Returns the remaining items of this iterator as a slice.

Examples

let mut vec = vec!['a', 'b', 'c'];
let mut drain = vec.drain(..);
assert_eq!(drain.as_slice(), &['a', 'b', 'c']);
let _ = drain.next().unwrap();
assert_eq!(drain.as_slice(), &['b', 'c']);

fn allocator(self: &Self) -> &A

Returns a reference to the underlying allocator.

fn keep_rest(self: Self)

Keep unyielded elements in the source Vec.

Examples

#![feature(drain_keep_rest)]

let mut vec = vec!['a', 'b', 'c'];
let mut drain = vec.drain(..);

assert_eq!(drain.next().unwrap(), 'a');

// This call keeps 'b' and 'c' in the vec.
drain.keep_rest();

// If we wouldn't call `keep_rest()`,
// `vec` would be empty.
assert_eq!(vec, ['b', 'c']);

`impl<'a, T, A> Freeze for Drain<'a, T, A>`

`impl<'a, T, A> RefUnwindSafe for Drain<'a, T, A>`

`impl<'a, T, A> Unpin for Drain<'a, T, A>`

`impl<'a, T, A> UnsafeUnpin for Drain<'a, T, A>`

`impl<'a, T, A> UnwindSafe for Drain<'a, T, A>`

`impl<'a, T, A: Allocator> AsRef for Drain<'a, T, A>`

fn as_ref(self: &Self) -> &[T]

`impl<I> IntoIterator for Drain<'a, T, A>`

fn into_iter(self: Self) -> I

`impl<T> Any for Drain<'a, T, A>`

fn type_id(self: &Self) -> TypeId

`impl<T> Borrow for Drain<'a, T, A>`

fn borrow(self: &Self) -> &T

`impl<T> BorrowMut for Drain<'a, T, A>`

fn borrow_mut(self: &mut Self) -> &mut T

`impl<T> From for Drain<'a, T, A>`

fn from(t: T) -> T: Returns the argument unchanged.

`impl<T, A: Allocator> DoubleEndedIterator for Drain<'_, T, A>`

fn next_back(self: &mut Self) -> Option<T>

`impl<T, A: Allocator> Drop for Drain<'_, T, A>`

fn drop(self: &mut Self)

`impl<T, A: Allocator> ExactSizeIterator for Drain<'_, T, A>`

fn is_empty(self: &Self) -> bool

`impl<T, A: Allocator> FusedIterator for Drain<'_, T, A>`

`impl<T, A: Allocator> Iterator for Drain<'_, T, A>`

fn next(self: &mut Self) -> Option<T>
fn size_hint(self: &Self) -> (usize, Option<usize>)

`impl<T, A: Allocator> TrustedLen for Drain<'_, T, A>`

`impl<T, U> Into for Drain<'a, T, A>`

fn into(self: Self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of [From]<T> for U chooses to do.

`impl<T, U> TryFrom for Drain<'a, T, A>`

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

`impl<T, U> TryInto for Drain<'a, T, A>`

fn try_into(self: Self) -> Result<U, <U as TryFrom<T>>::Error>

`impl<T: Send, A: Send + Allocator> Send for Drain<'_, T, A>`

`impl<T: Sync, A: Sync + Allocator> Sync for Drain<'_, T, A>`

`impl<T: fmt::Debug, A: Allocator> Debug for Drain<'_, T, A>`

fn fmt(self: &Self, f: &mut Formatter<'_>) -> Result