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charset="utf-8" Content-Transfer-Encoding: quoted-printable In Rust Binder I need to be able to determine whether a red/black tree is empty. Thus, add a method for that operation to replace rbtree.iter().next().is_none() This is terrible, so add a method for this purpose. We do not add a RBTree::len method because computing the number of elements requires iterating the entire tree, but checking whether it is empty can be done cheaply. Signed-off-by: Alice Ryhl Reviewed-by: Benno Lossin --- rust/kernel/rbtree.rs | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/rust/kernel/rbtree.rs b/rust/kernel/rbtree.rs index 8d978c8967475cc2631b50721798f7e8cd1551fd..9457134eb3afdf7a214a28fcbe2= e6b8065cc9a86 100644 --- a/rust/kernel/rbtree.rs +++ b/rust/kernel/rbtree.rs @@ -191,6 +191,12 @@ pub fn new() -> Self { } } =20 + /// Returns true if this tree is empty. + #[inline] + pub fn is_empty(&self) -> bool { + self.root.rb_node.is_null() + } + /// Returns an iterator over the tree nodes, sorted by key. pub fn iter(&self) -> Iter<'_, K, V> { Iter { --- base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494 change-id: 20250616-rbtree-is-empty-28f51fccb99a Best regards, --=20 Alice Ryhl