pub fn vacant(&self) -> usize
    {
        let q = unsafe { self.q.as_mut().bk_unwrap() };

        q.mem.len() - q.msg_cnt.cnt()
    }
/// Gets if there is a vacant message entry.
/// * Returns the number of vacant message entries.

Gets if there is a vacant message entry.
Returns the number of vacant message entries.
Gets if there is a vacant message entry . Returns the number of vacant message entries .
pub fn vacant(&self) -> usize
    {
        let q = unsafe { self.q.as_mut().bk_unwrap() };
        q.mem.len() - q.msg_cnt.cnt()
    }
pub fn vacant ( & self ) -> usize { let q = unsafe { self . q . as_mut ( ) . bk_unwrap ( ) } ; q . mem . len ( ) - q . msg_cnt . cnt ( ) }
Gets if there is a vacant message entry.
Gets if there is a vacant message entry .
&self
&self