M_COPYFLAGS
to->m_flags |= (from->m_flags & M_COPYFLAGS);
mcopy->m_flags |= (mflags & M_COPYFLAGS);
mcopy->m_flags |= (mflags & M_COPYFLAGS);
mcopy->m_flags |= (mflags & M_COPYFLAGS);
(to)->m_flags |= (from)->m_flags & M_COPYFLAGS; \