A guide to traversing the FFI boundary between Rust and other languages. A rendered version is available here. This guide is centred around the idea of building a REST client using Qt (C++) for the GUI and reqwest (Rust) for the business logic.

Building and viewing the book locally is really easy. First you need to get the source code:

$ git clone https://github.com/Michael-F-Bryan/rust-ffi-guide

Make sure you have mdbook installed:

$ cargo install mdbook

Then tell mdbook to build and serve the book:

$ mdbook serve --open

It should now be viewable at http://localhost:3000/ (if it didn't open up automatically).

To build the application itself you'll need the following installed:

• qt5
• rust (install with rustup)
• mdbook (cargo install mdbook)

In this application we're using cmake as the build system. The ci/test.sh script will make a build/ directory and invoke cmake to compile and test everything.

$ ./ci/test.sh

The final application should now be at build/gui.

Alternatively, if you don't want to install all the dependencies I've created a docker image (michaelfbryan/ffi-guide) for compiling Rust and Qt.

$ docker run \
    -v $(pwd):/code \
    -v ~/.cargo:$HOME/.cargo \
    -e CARGO_HOME=$HOME/.cargo \
    --user $UID \
    michaelfbryan/ffi-guide ci/test.sh

If there's anything you feel is missing or could be improved, please create an issue. Pull requests are welcome too!

• Michael-F-Bryan
• gurgalex
• adeschamps