Struct Cursor

pub struct Cursor<'a, K: BTreeKey, V, A: Allocator = Global> { /* private fields */ }

A cursor over the elements of a BTree.

Cursors point either to an element in the tree or to the end of the tree.

Iterators are more efficient than cursors. Prefer using them if you don’t need reverse iteration or if you don’t need to insert or remove elements in the tree.

This type is returned by BTree::cursor_at and BTree::cursor.

Implementations

impl<'a, K: BTreeKey, V, A: Allocator> Cursor<'a, K, V, A>

pub fn is_end(&self) -> bool

Returns true if the cursor points to the end of the tree.

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

Returns the key of the element that the cursor is currently pointing to, or None if the cursor is pointing to the end of the tree.

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

Returns a reference to the value that the cursor is currently pointing to, or None if the cursor is pointing to the end of the tree.

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

Returns the key and a reference to the value that the cursor is currently pointing to, or None if the cursor is pointing to the end of the tree.

pub fn next(&mut self)

Advances the cursor to the next element in the tree.

Panics

Panics if the cursor is pointing to the end of the tree.

pub fn prev(&mut self) -> bool

Advances the cursor to the previous element in the tree.

If the cursor is already at the first element of the tree then this method returns false and the cursor position is not moved.

pub fn iter(&self) -> Iter<'a, K, V, A>

Returns an iterator starting a the current element.

Iterators are more efficient than cursors. Prefer using them if you don’t need reverse iteration or if you don’t need to insert or remove elements in the tree.

Trait Implementations

impl<K: BTreeKey, V, A: Allocator> Clone for Cursor<'_, K, V, A>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.