pub fn open(&mut self) -> bool {
        // device already open
        if self.hd.is_some() {
            return true;
        }
        match self.dev {
            Some(ref mut d) => {
                self.hd = d.open().ok();
                true
            }
            None => false,
        }
    }
/// Open the device for starting IO operations.
///
/// Returns `true` if the device was successfully opened or is already open. Returns `false`
/// if the device can't be opened.
Open the device for starting IO operations.
Returns `true` if the device was successfully opened or is already open. Returns `false`
if the device can't be opened.
Open the device for starting IO operations . Returns ` true ` if the device was successfully opened or is already open . Returns ` false ` if the device can ' t be opened .
pub fn open(&mut self) -> bool {
        // device already open
        if self.hd.is_some() {
            return true;
        }
        match self.dev {
            Some(ref mut d) => {
                self.hd = d.open().ok();
                true
            }
            None => false,
        }
    }
pub fn open ( & mut self ) -> bool { // device already open if self . hd . is_some ( ) { return true ; } match self . dev { Some ( ref mut d ) => { self . hd = d . open ( ) . ok ( ) ; true } None => false , } }
Open the device for starting IO operations.
Open the device for starting IO operations .
&mut self
&mut self