pub fn is_hidden(filename: &OsStr) -> bool {
    filename
        .to_str()
        .map(|s| s.starts_with('.'))
        .unwrap_or(false)
}
/// Checks if a filename is prefixed by a '.' character.
/// If the path cannot be read as UTF-8, assume it isn't hidden.
Checks if a filename is prefixed by a '.' character.
If the path cannot be read as UTF-8, assume it isn't hidden.
Checks if a filename is prefixed by a ' . ' character . If the path cannot be read as UTF - 8 assume it isn ' t hidden .
pub fn is_hidden(filename: &OsStr) -> bool {
    filename
        .to_str()
        .map(|s| s.starts_with('.'))
        .unwrap_or(false)
}
pub fn is_hidden ( filename : & OsStr ) -> bool { filename . to_str ( ) . map ( | s | s . starts_with ( '.' ) ) . unwrap_or ( false ) }
Checks if a filename is prefixed by a '.'
Checks if a filename is prefixed by a ' . '
filename
&OsStr
filename
&OsStr