You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mac.rs
    path of file: ./repos/FlyingCarpet/core/src
    
    the code of the file until where you have to start completion: use regex::Regex;

use crate::{utils, PeerResource, WiFiInterface};

use super::{Mode, Peer, UI};
use std::error::Error;
use std::ffi::c_char;
use std::process;

extern "C" {
    fn joinAdHoc(cSSID: *const c_char, cPassword: *const c_char) -> u8;
}

// unused stu
    
unsafe fn join_hotspot(ssid: &str, password: &str) -> Result<(), Box<dyn Error>> {
    // TODO: these are never reclaimed
    let ssid = utils::rust_to_c_string(ssid);
    let password = utils::rust_to_c_string(&password);
    if joinAdHoc(ssid, password) == 0 {
        Err("couldn't find hotspot")?;
    }
    Ok(())
}