rust-block VS rust-bindgen

let block = ConcreteBlock::new(move |key: *const c_char, value: xpc_object_t| { unsafe { xpc_retain(value) }; let str_key = unsafe { CStr::from_ptr(key).to_string_lossy().to_string() }; let xpc_object: XPCObject = value.into(); map_refcell .borrow_mut() .insert(str_key, xpc_object.into()); true }); // https://github.com/SSheldon/rust-block#creating-blocks let block = block.copy(); let ok = unsafe { xpc_dictionary_apply(object.as_ptr(), &*block as *const _ as *mut _) };

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.