ref-array-di | Create C typed "array" instances on top of Buffers | Runtime Evironment library

and contains an array so it is sufficiently complicated that I want to do the allocation in Rust and have Node.JS receive a complete object,

Containing an array was the tricky/trap part. Arrays in C (ergo FFI) tend to be zero terminated, but there's no guarantee that things work a particular way for arrays of structs.

Here's what we had to do:

1. In Rust, expose a struct with a length member, and a pointer to a single item.
2. In Rust, allocate a vector of our things and use into_boxed_slice() to forget it, this gives a pointer to the first one.
3. Fill the length property on our struct

Everything like in the example we posted first.

In node.js however it's a bit different, the working code was nearly identical to what we had, here's the types: