Rust port of `criterion` for benchmarking

[graydon]

The built in unit tester presently contains some very crude one-off automated benchmarking stuff. It was initially a clone of the Go testing.B benchmark system (http://golang.org/pkg/testing/#B) but started to drift towards doing statistical measurement in order to get a more stable signal.

I believe Bryan O'Sullivan's criterion library (https://github.com/bos/criterion) is the state of the art here. We should port / emulate whatever it does well.

[catamorphism]

(bug triage) Good idea; not a blocker IMO.

[Aatch]

Visiting for triage.

This would be nice, but still isn't a high-priority.

[schuster]

I thought I might try to write this to help me learn Rust. I've found the testing guide and the various benchmark tests in the code. Are there any other resources I should be aware of, or design goals to keep in mind (other than emulating criterion)?

I'll try to get something simple working, post it, and request feedback as I go.

[japaric]

I'm tackling this issue here, I'll love to get feedback!

[kud1ing]

Is this fixed by https://github.com/japaric/criterion.rs ?
Is it already usable for supporting #18085 ?

[steveklabnik]

I'm pulling a massive triage effort to get us ready for 1.0. As part of this, I'm moving stuff that's wishlist-like to the RFCs repo, as that's where major new things should get discussed/prioritized.

This issue has been moved to the RFCs repo: rust-lang/rfcs#651