bors 70c5f6efc4 Auto merge of #75200 - ssomers:btree_valmut, r=Mark-Simulacrum ... BTreeMap: introduce marker::ValMut and reserve Mut for unique access The mutable BTreeMap iterators (apart from `DrainFilter`) are double-ended, meaning they have to rely on a front and a back handle that each represent a reference into the tree. Reserve a type category `marker::ValMut` for them, so that we guarantee that they cannot reach operations on handles with borrow type `marker::Mut`and that these operations can assume unique access to the tree. Including #75195, benchmarks report no genuine change: ``` benchcmp old new --threshold 5 name old ns/iter new ns/iter diff ns/iter diff % speedup btree::map::iter_100 3,333 3,023 -310 -9.30% x 1.10 btree::map::range_unbounded_vs_iter 36,624 31,569 -5,055 -13.80% x 1.16 ``` r? @Mark-Simulacrum		2020-09-04 23:16:23 +00:00
..
benches	fix benchmark compile errors	2020-09-03 20:59:33 +02:00
src	Auto merge of #75200 - ssomers:btree_valmut, r=Mark-Simulacrum	2020-09-04 23:16:23 +00:00
tests	remove empty Vec extend optimization	2020-09-03 20:59:35 +02:00
Cargo.toml	mv std libs to library/	2020-07-27 19:51:13 -05:00