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: main.rs
    path of file: ./repos/ZLUDA/process_address_table/src
    
    the code of the file until where you have to start completion: use libloading::Library;
use std::collections::BTreeSet;
use std::collections::HashMap;
use std::ptr;

// Version history taken from here: https://developer.nvidia.com/cuda-toolkit-archive
static CUDA_VERSIONS: &[&'static str] = &[
    "12.2.0", "12.1.1", "12.1.0", "12.0.1", "12.0.0", "11.8.0", "11.7.1", "11.7.0", "11.6.2",
    "11.6.1", "11.6.0", "11.5.2", "11.5.1", "11.5.0", "11.4.4", "11.4.3", "11.4.2", "11.4.1",
    "11.4.0", "11.3.1", "11.3.0", "11.2.2", "11.2.1", "11.2.0", "11.1.1", "11.1.0", "11.0.3",
    "11.0.2", "11.0.1", "11.0", "10.2", "10.1", "10.1", "10.1", "10.0", "9.2", "9.1", "9.0", "8.0",
    "7.5", "7.0", "6.5", "6.0", "5.5", "5.0", "4.2", "4.1", "4.0", "3.2", "3.1", "3.0", "2.3",
    "2.2", "2.1", "2.0", "1.1", "1.0",
];

struct FnVersionTable<'a> {
    fn_: &'a str,
    flag: u64,
    versions: Vec<(u32, &'a str)>,
}

impl<'a> FnVersionTable<'a> {
    fn new(fn_: &'a str, flag: u64) -> Self {
        Self {
            fn_,
            flag,
            versions: Vec::new(),
        }
    }

    fn push(&mut self, ver: u32, name: &'a str) {
        if Some(name) == self.versions.last().map(|(_, n)| 
    
unsafe fn main_impl() {
    let all_exports = os::get_nvcuda_exports();
    let mut cuda_versions = CUDA_VERSIONS
        .iter()
        .map(cuda_version_to_integer)
        .collect::<Vec<_>>();
    cuda_versions.sort_unstable();
    let cuda = Library::new(os::CUDA_PATH).unwrap();
    let mut cu_get_proc_address = cuda
        .get::<unsafe extern "C" fn(
            symbol: *const ::std::os::raw::c_char,
            pfn: *mut *mut ::std::os::raw::c_void,
            cudaVersion: ::std::os::raw::c_int,
            flags: u64,
        ) -> u32>(b"cuGetProcAddress\0")
        .unwrap()
        .into_raw();
    let cuda_impl = if cfg!(windows) {
        // Done purely to force load of nvcuda64.dll on Windows
        cu_get_proc_address("cuInit\0".as_ptr() as _, &mut ptr::null_mut(), 0, 0);
        let nvcuda64 = Library::new(os::CUDA_IMPL_LIB).unwrap();
        cu_get_proc_address = nvcuda64
            .get::<unsafe extern "C" fn(
                symbol: *const ::std::os::raw::c_char,
                pfn: *mut *mut ::std::os::raw::c_void,
                cudaVersion: ::std::os::raw::c_int,
                flags: u64,
            ) -> u32>(b"cuGetProcAddress\0")
            .unwrap()
            .into_raw();
        nvcuda64
    } else {
        Library::new(os::CUDA_IMPL_LIB).unwrap()
    };
    let (nvcuda_exports, cuda_impl_exports) = get_impl_fns(&cuda_impl, all_exports);
    println!("// GENERATED AUTOMATICALLY BY process_address_table, DON'T CHANGE MANUALLY");
    println!("match (name, flag) {{");
    for export in nvcuda_exports.iter() {
        for flag in [0, 1, 2] {
            let mut ver_table = FnVersionTable::new(export, flag);
            for ver in cuda_versions.iter().copied() {
                let mut fnptr = ptr::null_mut();
                let error = cu_get_proc_address(export.as_ptr() as _, &mut fnptr, ver as i32, flag);
                if error == 500 {
                    continue;
                }
                assert_eq!(0, error);
                let fn_name = &cuda_impl_exports[&fnptr];
                ver_table.push(ver, fn_name);
            }
            ver_table.print();
        }
    }
    println!("    _ => std::ptr::null_mut()");
    println!("}}");
}