q = append([]AST{qual}, q...)
			st.advance(1)
		} else if len(st.str) > 1 && st.str[0] == 'D' {
			var qual AST
			switch st.str[1] {
			case 'x':
				qual = &Qualifier{Name: "transaction_safe"}
				st.advance(2)
			case 'o':
				qual = &Qualifier{Name: "noexcept"}
				st.advance(2)
			case 'O':
				st.advance(2)
				expr := st.expression()

	1<<_Switch |
	1<<_Type |
	1<<_Var

// advance consumes tokens until it finds a token of the stopset or followlist.
// The stopset is only considered if we are inside a function (p.fnest > 0).
// The followlist is the list of valid tokens that can follow a production;
// if it is empty, exactly one (non-EOF) token is consumed to ensure progress.
func (p *parser) advance(followlist ...token) {
	if trace {

	"internal/trace/version"
)

// ordering emulates Go scheduler state for both validation and
// for putting events in the right order.
//
// The interface to ordering consists of two methods: Advance
// and Next. Advance is called to try and advance an event and
// add completed events to the ordering. Next is used to pick
// off events in the ordering.
type ordering struct {
	gStates     map[GoID]*gState

  return op
      ->walk([&](Operation* walked_op) {
        if (op == walked_op) return WalkResult::advance();
        if (walked_op->hasAttr(kXlaOutsideCompilationAttr)) {
          return WalkResult::interrupt();
        }
        return WalkResult::advance();
      })
      .wasInterrupted();
}

// Returns whether `op` or any ancestors of `op` are outside compiled.

    int skipped = advance(iterator, position);
    if (!iterator.hasNext()) {
      throw new IndexOutOfBoundsException(
          "position ("
              + position
              + ") must be less than the number of elements that remained ("
              + skipped
              + ")");
    }
    return iterator.next();
  }

  /**

    int skipped = advance(iterator, position);
    if (!iterator.hasNext()) {
      throw new IndexOutOfBoundsException(
          "position ("
              + position
              + ") must be less than the number of elements that remained ("
              + skipped
              + ")");
    }
    return iterator.next();
  }

  /**

    list.add("b");
    Iterator<String> iterator = list.iterator();
    advance(iterator, 1);
    assertEquals("b", iterator.next());
  }

  public void testAdvance_pastEnd() {
    List<String> list = newArrayList();
    list.add("a");
    list.add("b");
    Iterator<String> iterator = list.iterator();
    advance(iterator, 5);
    assertFalse(iterator.hasNext());
  }

	mbits = markBitsForAddr(base)
	if mbits.mask != 1 {
		throw("markBitsForSpan: unaligned start")
	}
	return mbits
}

// advance advances the markBits to the next object in the span.
func (m *markBits) advance() {
	if m.mask == 1<<7 {
		m.bytep = (*uint8)(unsafe.Pointer(uintptr(unsafe.Pointer(m.bytep)) + 1))
		m.mask = 1
	} else {
		m.mask = m.mask << 1
	}
	m.index++

    @CheckForNull WriteThroughEntry lastReturned;

    HashIterator() {
      nextSegmentIndex = segments.length - 1;
      nextTableIndex = -1;
      advance();
    }

    @Override
    public abstract T next();

    final void advance() {
      nextExternal = null;

      if (nextInChain()) {
        return;
      }

      if (nextInTable()) {
        return;
      }

    @CheckForNull WriteThroughEntry lastReturned;

    HashIterator() {
      nextSegmentIndex = segments.length - 1;
      nextTableIndex = -1;
      advance();
    }

    @Override
    public abstract T next();

    final void advance() {
      nextExternal = null;

      if (nextInChain()) {
        return;
      }

      if (nextInTable()) {
        return;
      }