rust-bindgen VS hyper

Rust supports two kinds of FFI: calling into Rust from another language; and calling into another language from Rust. Most of the thought and tooling that exists right now is organized around the second kind. For example, bindgen is a popular tool that generates useful Rust wrappers from a C or C++ header file.

I have looked into bindgen, but found that it would not be feasible due to OMPL not having a C API, just C++.

Yes! Are you running LLVM version 16.0.0 or newer, by any chance? I believe this is an issue with some builds of bindgen with newer versions of LLVM. See https://github.com/rust-lang/rust-bindgen/issues/2488

On native, you have to define a C API, probably using a header file. Even if both sides are implemented in Rust, they have to speak that C API (documentation).

Bindgen has some functionality for direct talk to C++ https://github.com/rust-lang/rust-bindgen

I am trying to use rust-bindgen (https://github.com/rust-lang/rust-bindgen) to link a static C library (say `libexample.a`) which is compiled in a separate project with CMake. The `libexample.a` depends on other libraries (for example `libcurl.a`) installed on the system.

It looks like the guy you're replying too was kind of an ass, but I do want to point out for anyone else reading that that's not actually that much of a technical limitation: rust code can natively call C code. The main thing you need is a translation of the C library's header file so rustc knows what C functions and structs exist, and that can be automatically generated with bindgen.

It's quite the different approach, but you could consider using bindgen instead.

Use bindgen or CXX to create Rust bindings for the C or C++ libraries.

> If you are equally picky and constrain yourself to parts of the ecosystem which care about binary size, you still have more options and can avoid size issues.

What's an example of this for, say, libcurl? On my system it has a tiny number of recursive dependencies, around a dozen. [0] Furthermore if I want to write a C program that uses libcurl I have to download zero bytes of data ... because it's a shared library that is already installed on my system, since so many programs already use it.

I don't really know the appropriate comparison for Rust. reqwest seems roughly comparable, but it's an HTTP client library, and not a general purpose network client like curl. Obviously curl can do a lot more. Even the list of direct dependencies for reqwest is quite long [1], and it's built on top of another http library [2] that has its own long list of dependencies, a list that includes tokio, no small library itself.

In terms of final binary size, the installed size of the curl package on my system, which includes both the command line tool and development dependencies for libcurl, is 1875.03 KiB.

[0] I'm excluding the dependency on the ca-certificates package, since this only provides the certificate chain for TLS and lots of programs rely on it.

[1] https://crates.io/crates/reqwest/0.11.24/dependencies

[2] https://crates.io/crates/hyper/0.14.28/dependencies

hyper-based HTTP server generating JSON responses. Written in Rust.

tokio / hyper / toml / serde / serde_json / json5 / console

Using Rust here was immensely helpful, using libraries made by the community like https://github.com/hyperium/hyper really powered up the development of Signway, so glad to see this kind of awesome crates made public. Hope that it continues to be like that despite the current controversies.

- Discord sends a slightly weird request by specifying content length (a bug in hyper we've not yet upgraded to fix, https://github.com/hyperium/hyper/commit/fb90d30c02d8f7cdc9a643597d5c4ca7a123f3dd)