rust-lang/rust — pull request #20082 by pczarn (2014-12-20 18:56:48+00:00)
Title: Implement bounded iterators for BTree

Also, iteration is simplified:
```
before
test btree::map::bench::iter_1000 ... bench: 17177 ns/iter (+/- 6302)
test btree::map::bench::iter_100000 ... bench: 1735731 ns/iter (+/- 23908)
test btree::map::bench::iter_20 ... bench: 386 ns/iter (+/- 148)
after
test btree::map::bench::iter_1000 ... bench: 15777 ns/iter (+/- 346)
test btree::map::bench::iter_100000 ... bench: 1602604 ns/iter (+/- 73629)
test btree::map::bench::iter_20 ... bench: 339 ns/iter (+/- 91)
```
cc @gereeter @cgaebel
r? @Gankro