bors cbab347e68 Auto merge of #79376 - ssomers:btree_choose_parent_kv, r=Mark-Simulacrum
BTreeMap: clarify comments and panics around choose_parent_kv

Fixes a lie in recent code: `unreachable!("empty non-root node")` should shout "empty internal node", but it might as well be good and keep quiet

r? `@Mark-Simulacrum`
2020-12-13 14:42:37 +00:00
..
2020-09-29 21:39:24 +08:00