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: udev.rs
    path of file: ./repos/smithay/src/backend
    
    the code of the file until where you have to start completion: //! `udev` related functionality for automated device scanning
//!
//! This module mainly provides the [`UdevBackend`], which monitors available DRM devices and acts as
//! an event source to be inserted in [`calloop`], generating events whene
    
pub fn all_gpus<S: AsRef<str>>(seat: S) -> io::Result<Vec<PathBuf>> {
    let mut enumerator = Enumerator::new()?;
    enumerator.match_subsystem("drm")?;
    enumerator.match_sysname("card[0-9]*")?;
    Ok(enumerator
        .scan_devices()?
        .filter(|device| {
            device
                .property_value("ID_SEAT")
                .map(|x| x.to_os_string())
                .unwrap_or_else(|| OsString::from("seat0"))
                == *seat.as_ref()
        })
        .flat_map(|device| device.devnode().map(PathBuf::from))
        .collect())
}