Remove StreamObj and use Pin<Box<dyn Stream>> instead

[gruberb]

According to rust-lang/futures-rs#1352, StreamObj is going to be removed in favour for Pin<Box<dyn Stream>>.

type BoxStream<'a, T> = Pin<Box<dyn Stream<Item = T> + Send + 'a>>;

The http-service is using the StreamObj for its Body:
https://github.com/rustasync/http-service/blob/master/src/lib.rs#L29

[Nemo157]

Github won't let me access my fork at the moment ("The backend storage is temporarily offline."), but I prepared a patch to check that the futures change will be a positive here. (The lack of Debug is annoying, but I don't see any easy way around that).

[Kerollmops]

The StreamObj type has been removed and make tide not able to compile.

I thought the semver rule was to keep the exact specified version of a dependency when talking about pre-release/alpha/beta (i.e. =0.3.0-alpha.14 and not downloading the 0.3.0-alpha.15).

[Nemo157]

=0.3.0-alpha.14 should not download alpha.15, http-service uses 0.3.0-alpha.14 which allows Cargo to install the "semver-compatible" alpha.15. If you want to lock it down with = then that would block it.

It looks like Github has my fork working now, so I can push the patch I prepared and open a PR shortly.

[Kerollmops]

My only dependency is tide 0.1.1 which directly depends on futures-preview ^0.3.0-alpha.14 and http-service ^0.1.5 which depends on futures-preview ^0.3.0-alpha.14.

In my dependency graph I only have the 0.3.0-alpha.15 version of futures-preview.
I do not write =0.3.0-alpha.14 by hand, would it be possible for the next tide and http-service versions to depend on =0.3.0-alpha.14 to prevent this kind of breaking.

[Nemo157]

@Kerollmops as a workaround for now you can add an explicit futures-preview = "=0.3.0-alpha.14" dependency to your project and Cargo will force everything to use that one version (it doesn't allow multiple semver compatible versions in a build graph).

I'm not directly associated with either project so I can't say whether Tide and http-service want to switch to exact versions to avoid this breakage. I'll leave that for the main devs to answer.

[Kerollmops]

Wow, did not know that. Thank you! TIL something useful and it work!