no_std support

[vadixidav]

This is the follow-up to #46. I fixed the build issue with the benchmark trying to use core when it is using std. I also added CI tests for no_std. If CI fails, I will make additional changes. I have not previously used Travis CI, so I don't know if what I wrote will work, but that is what CI is for 😃.

Closes #46

[vadixidav]

@bluss Alright, got the CI working. Let me know if I need to do anything else.

[vadixidav]

@bluss Pinging you again just to take a look and approve or suggest changes.

[vadixidav]

@bluss Hey, just pinging you again. Let me know if everything looks good.

[bluss]

Thanks, looks good! I think normally we'd bump to version 0.3 here since we have a Rust MSV bump. Can't that be avoided, though?

[vadixidav]

@bluss I just went through the rounds and tried some stuff. It turns out to not be possible (to name alloc in stable): https://blog.rust-lang.org/2019/07/04/Rust-1.36.0.html

It was Rust 1.36 at which the alloc crate was stabilized. I think it makes the most sense to move on with this approach of bumping the version. I have reset the branch back to where it was. If you insist, we can maintain separate lines for all allocation regions in the code, though I am not 100% sure if that will work either and would have to experiment. Even if we did that, we would only be supporting stable on an older Rust, and no_std on 1.36, which is strange.

[bluss]

We just need Rust 1.36 if the std feature is disabled. So we don't need to break existing users actually

[vadixidav]

Alright, I will work on getting it to work with std on 1.28 and no_std on 1.36 simultaneously. I will mess around with the CI as well to ensure we test that.

[vadixidav]

@bluss I believe it have it all working (locally at least). Do you mind if I also add two commits: one to reformat with rustfmt and one to fix all clippy lints (either by actually fixing them or by annotating them with allows)? I can do that in another PR as well if you like.

[bluss]

Thanks for the fixes. I think formatting changes in a PR are detrimental since it's harder to review the actual changes that way, it is an impediment to easy inspection and approval.

Could you rebase and squash your changes? Then we can include them.

[vadixidav]

Thanks for the fixes. I think formatting changes in a PR are detrimental since it's harder to review the actual changes that way, it is an impediment to easy inspection and approval.

Could you rebase and squash your changes? Then we can include them.

I will do this later today without the formatting.

[bluss]

Don't worry about adding/subtracting formatting in particular, now I've read it. But let's reformat in a separate pr. :)

[vadixidav]

Don't worry about adding/subtracting formatting in particular, now I've read it. But let's reformat in a separate pr. :)

Okay, so just for clarification, you want me to rebase this work (including its formatting changes) onto master, then you want a separate PR with a total reformat of the repository. Is this right? If so, I will get on that later, and if not, let me know.

[bluss]

Sure. Main interest is in squashing together some of the commits and make it ready for merge. If the travis failure on 1.28 is unrelated we should ignore it now too.

[vadixidav]

@bluss Alright, this should be all good to go. It passed CI before I squashed it so it should be good. I had to just make a small modification to deal with CI.

[vadixidav]

Also you can close the other PR #46.

[bluss]

Thanks a lot!

[bluss]

In release 0.2.4