Implement step_by

[hherman1]

I believe this should be parallelizable? The iterator is currently in nightly rust:

https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.step_by

[cuviper]

It should be possible, yes. I think I'd prefer to wait for Iterator::step_by to stabilize though, so we can make sure to match its signature.

[lu-zero]

The iterator is now in stable since a while :)

[gbip]

This would be a very useful feature 😄

[emmanuelantony2000]

Can i try to implement it?

[cuviper]

Go for it!

[FlyingCanoe]

I have created a pull request adding this future, but It depend on std StepBy being a double ended iterator. This trait as bean stabilise in rustc 1.38. Does bumping the minimal rustc version is acceptable for this future?

[cuviper]

I don't think we should bump the MSRV for this feature. We can either implement our own version of the StepBy iterator, or add a build script which detects support to set a cfg (so it wouldn't be available at all earlier). Use autocfg if you go for a build script, where you can probe an expression like (0..10).step_by(2).rev().

[Coder-256]

I think that this #726 was supposed to close this. :)

[cuviper]

Yes, thanks!