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: windows.rs
    path of file: ./repos/hostname/src
    
    the code of the file until where you have to start completion: use std::io;
#[cfg(feature = "set")]
us
    
pub fn get() -> io::Result<OsString> {
    use windows::core::PWSTR;
    use windows::Win32::System::SystemInformation::GetComputerNameExW;

    let mut size = 0;
    unsafe {
        // Don't care much about the result here,
        // it is guaranteed to return an error,
        // since we passed the NULL pointer as a buffer
        let result = GetComputerNameExW(
            ComputerNamePhysicalDnsHostname,
            PWSTR::null(),
            &mut size,
        );
        debug_assert_eq!(result.0, 0);
    };

    let mut buffer = Vec::with_capacity(size as usize);

    let result = unsafe {
        GetComputerNameExW(
            ComputerNamePhysicalDnsHostname,
            PWSTR::from_raw(buffer.as_mut_ptr()),
            &mut size,
        )
    };

    if !result.as_bool() {
        Err(io::Error::last_os_error())
    } else {
        unsafe {
            buffer.set_len(size as usize);
        }

        Ok(OsString::from_wide(&buffer))
    }
}