Can a combined rust and C++ project maintain Cargo compatability?

[eladmaimoni]

I am building a combined rust and C++ project. My goal is to have rust crates that C++ libraries may use through ffi and a rust binary that will link both C++ libraries and rust libraries.

If I simplify this, I have the following targets:

• rcore - a rust library crate
• ccore - a C++ library, depends on rcore through ffi bindings
• app - a rust binary application, links both ccore and rcore

I am experimenting with bazel, and currently trying to maintain the cargo files (using crate universe). My main incentive for maintaining the cargo files is to be able to use the cargo ecosystem and IDE integration.
With C++, I use a bazel only.

However, I am not sure how I should express the fact that the rust binary application depends on a C++ target(s). I can't express that in cargo I guess (since these are bazel targets) and specifying it in bazel will break cargo compatibility.
The documentation strongly implies that I need to go the "Cargo Free" path. however, I fear of losing all the neat IDE features that come with cargo.

So my question is - is is possible to have a rust crate depend on a C++ target while still maintaining cargo compatibility? or in this scenario I must do a cargo free approach?

[brunal]

One way is to handle the C++ deps is the build script -- be it picking a bundled object file, or compiling using cmake/cc. cmake and cc are crates that help with that: https://crates.io/crates/cmake & https://crates.io/crates/cc. Look at their dependents for inspiration.