Write generated bridge files to OUT_DIR as-is

[stoically]

Possible way to fix #213. Currently breaks things, if this is something that might make sense I'm happy to look into making it work.

This requires consumers to add

let out_dir = env::var("OUT_DIR").unwrap();
// ...
cxx.include(out_dir);

to their build script.

[dtolnay]

Thanks for the PR!

As you can tell, the Cargo story is not completely worked out yet; I have mostly been developing using Bazel and using Buck at work. I will play around with your crate and try to figure out what the right behavior should be. I think this PR is in the right direction but I think we would want to use a subdirectory of OUT_DIR to avoid disrupting other things that the crate's build script might be doing in OUT_DIR. Also I want crates to be able to include generated headers from their dependencies, so only putting them in OUT_DIR would not be sufficient because crates generally do not get to access other crates' OUT_DIR. So we'd want generated headers symlinked to a predictable place elsewhere in the target dir and probably namespaced by the dependency's crate name.

[dtolnay]

I published cxx and cxx-build 0.4, which hopefully fixes all of the brittleness in the Cargo-based workflow, including #213. I know it's been a really long time but if you are still interested in this, would you be able to give 0.4 a try with your crate?

[stoically]

Works like a charm now. Thanks a lot for working on this! (And sorry that I didn't pick up my slack here after your fast response)