[fluffything]

Its not that it doesn't work, but rather that it is not guaranteed to work, and the design is basically a pile of duck tape. For example, you can use Rust arrays in a C FFI declaration, but that won't do what you think it does:

    extern "C" { fn foo(x: [u8; 42]); }

does not declare the C function

    void foo(uint8_t x[42]);