It will work if you only use raw pointers everywhere, like it's C. Don't use slices or strings; just pass a pointer to the first element of an array, and either pass its length separately or provide a sentinel value (like C's null terminated strings). Navigate balanced search trees using aliasing, raw, mutable pointers. Etc. This person compares the translation of C to Rust, literally versus idiomatically: https://cliffle.com/p/dangerust/

There will probably be weird behavior, though, because Rust optimizes based on assumptions about boxes and references. For example, if you have 3 raw pointers to some object live at once, and you give some library function a mutable reference made from one of those pointers, the compiler will optimize assuming it has exclusive access to that object, and it may make incorrect assumptions.