Struct HeadTail 

struct HeadTail<I>
where
    I: Iterator,
{
    head: I::Item,
    tail: I,
}

Head element and Tail iterator pair

PartialEq, Eq, PartialOrd and Ord are implemented by comparing sequences based on first items (which are guaranteed to exist).

The meanings of PartialOrd and Ord are reversed so as to turn the heap used in KMerge into a min-heap.

Fields

head: I::Item

tail: I

Implementations

impl<I> HeadTail<I>

where I: Iterator,

fn new(it: I) -> Option<Self>

Constructs a HeadTail from an Iterator. Returns None if the Iterator is empty.

fn next(&mut self) -> Option<I::Item>

Get the next element and update head, returning the old head in Some.

Returns None when the tail is exhausted (only head then remains).

fn size_hint(&self) -> (usize, Option<usize>)

Hints at the size of the sequence, same as the Iterator method.

Trait Implementations

impl<I> Clone for HeadTail<I>

where I: Iterator + Clone, I::Item: Clone,

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<I> Debug for HeadTail<I>

where I: Iterator + Debug, I::Item: Debug,

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

Formats the value using the given formatter.