bors ffaf857045 Auto merge of #88448 - xu-cheng:btree-blk-build, r=Mark-Simulacrum ... BTreeMap/BTreeSet::from_iter: use bulk building to improve the performance Bulk building is a common technique to increase the performance of building a fresh btree map. Instead of inserting items one-by-one, we sort all the items beforehand then create the BtreeMap in bulk. Benchmark ``` ./x.py bench library/alloc --test-args btree::map::from_iter ``` * Before ``` test btree::map::from_iter_rand_100 ... bench: 3,694 ns/iter (+/- 840) test btree::map::from_iter_rand_10_000 ... bench: 1,033,446 ns/iter (+/- 192,950) test btree::map::from_iter_seq_100 ... bench: 5,689 ns/iter (+/- 1,259) test btree::map::from_iter_seq_10_000 ... bench: 861,033 ns/iter (+/- 118,815) ``` * After ``` test btree::map::from_iter_rand_100 ... bench: 3,033 ns/iter (+/- 707) test btree::map::from_iter_rand_10_000 ... bench: 775,958 ns/iter (+/- 105,152) test btree::map::from_iter_seq_100 ... bench: 2,969 ns/iter (+/- 336) test btree::map::from_iter_seq_10_000 ... bench: 258,292 ns/iter (+/- 29,364) ```		2021-09-07 02:24:11 +00:00
..
benches	add benchmark for BTreeMap::from_iter	2021-08-28 17:18:43 -07:00
src	Auto merge of #88448 - xu-cheng:btree-blk-build, r=Mark-Simulacrum	2021-09-07 02:24:11 +00:00
tests	Rollup merge of #88040 - nbdd0121:btreemap, r=m-ou-se	2021-09-01 09:23:23 +02:00
Cargo.toml	rfc3052: Remove authors field from Cargo manifests	2021-07-29 14:56:05 -07:00