FFI type aliases for specific variants of a generic Rust type?

[chjordan]

Hi all. Apologies if this has been answered elsewhere; a bit of digging didn't turn up anything.

I have a (type)[Marlu/jones.rs at 582016f522ae73caf7c7d2a59ca08c37dc09c1b4 · MWATelescope/Marlu · GitHub] that can either be Jones<f64> or Jones`:

use num_complex::Complex
use num_traits::{float::FloatCore, Float, Num, NumAssign, Zero};

#[repr(transparent)]
#[derive(Clone, Copy, Default, PartialEq, Eq)]
pub struct Jones<F: Float + Num>([Complex<F>; 4]);

This works great for Rust code. But, I use this same type for some CUDA code that is "baked" into my Rust code. To copy to/from the device, I've defined two C++ structs that I cast to/from, and I expose them to Rust with bindgen.

typedef struct JonesF32 {
    // Real part of the (0,0) component
    float j00_re;
    // Imaginary part of the (0,0) component
    float j00_im;
    // Real part of the (0,1) component
    float j01_re;
    // Imaginary part of the (0,1) component
    float j01_im;
    // Real part of the (1,0) component
    float j10_re;
    // Imaginary part of the (1, 0) component
    float j10_im;
    // Real part of the (1,1) component
    float j11_re;
    // Imaginary part of the (1,1) component
    float j11_im;
} JonesF32;

typedef struct JonesF64 {
    // Real part of the (0,0) component
    double j00_re;
    // Imaginary part of the (0,0) component
    double j00_im;
    // Real part of the (0,1) component
    double j01_re;
    // Imaginary part of the (0,1) component
    double j01_im;
    // Real part of the (1,0) component
    double j10_re;
    // Imaginary part of the (1, 0) component
    double j10_im;
    // Real part of the (1,1) component
    double j11_re;
    // Imaginary part of the (1,1) component
    double j11_im;
} JonesF64;

This feels very dirty. Is there a way to keep using my generic Jones type on the Rust side without having to cast to/from these types on the CUDA side? Or to generally handle this kind of thing cleaner? Thanks in advance!