bors 89524d0f8e Auto merge of #79520 - ssomers:btree_cleanup_1, r=Mark-Simulacrum
BTreeMap: clean up access to MaybeUninit arrays

Stop exposing and using immutable access to `MaybeUninit` slices when we need and have exclusive access to the tree.

r? `@Mark-Simulacrum`
2020-12-26 16:47:33 +00:00
..
2020-09-29 21:39:24 +08:00