70c5f6efc4
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 |
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| .. | ||
| alloc | ||
| backtrace@4083a90168 | ||
| core | ||
| panic_abort | ||
| panic_unwind | ||
| proc_macro | ||
| profiler_builtins | ||
| rtstartup | ||
| rustc-std-workspace-alloc | ||
| rustc-std-workspace-core | ||
| rustc-std-workspace-std | ||
| std | ||
| stdarch@78891cdf29 | ||
| term | ||
| test | ||
| unwind | ||