Struct Cursor

pub struct Cursor<'a, K, V>
where
    K: 'a,
    V: 'a,
{ /* private fields */ }

A cursor over a BTreeMap.

A Cursor is like an iterator, except that it can freely seek back-and-forth.

Cursors always point to an element in the tree, and index in a logically circular way. To accommodate this, there is a “ghost” non-element that yields None between the last and first elements of the tree.

A Cursor is created with the BTreeMap::lower_bound and BTreeMap::upper_bound methods.

Implementations

impl<'a, K, V> Cursor<'a, K, V>

pub fn key(&self) -> Option<&'a K>

Returns a reference to the key of the element that the cursor is currently pointing to.

This returns None if the cursor is currently pointing to the “ghost” non-element.

pub fn value(&self) -> Option<&'a V>

Returns a reference to the value of the element that the cursor is currently pointing to.

This returns None if the cursor is currently pointing to the “ghost” non-element.

pub fn key_value(&self) -> Option<(&'a K, &'a V)>

Returns a reference to the key and value of the element that the cursor is currently pointing to.

This returns None if the cursor is currently pointing to the “ghost” non-element.

Trait Implementations

impl<K, V> Clone for Cursor<'_, K, V>

fn clone(&self) -> Cursor<'_, K, V>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<K, V> Debug for Cursor<'_, K, V>

where K: Debug, V: Debug,

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

Formats the value using the given formatter.