Using Rust code in D should be relatively easy: expose C API, compile it into a shared library and use it on the D side as any other library. cbindgen (https://github.com/eqrion/cbindgen) can help with generation of header files. Static linking is possible as well.
Using D code in Rust probably will be much more painful and I am not sure if it can be done 100% safely...
Using D code in Rust probably will be much more painful and I am not sure if it can be done 100% safely...