public Enumerator(LoopArray <T> inst)
            {
                this.inst = inst;

                m_init_pos = inst.m_writepos;
                m_size     = inst.m_size;

                m_idx = -1;
            }
 public void Dispose()
 {
     inst       = null;
     m_init_pos = m_idx = m_size = 0;
 }