Method operator&=

ext/include/llvm/ADT/SparseBitVector.h:587–632

Intersect our bitmap with the RHS and return true if ours changed.

  // Intersect our bitmap with the RHS and return true if ours changed.
  bool operator&=(const SparseBitVector &RHS) {
    if (this == &RHS)
      return false;

    bool changed = false;
    ElementListIter Iter1 = Elements.begin();
    ElementListConstIter Iter2 = RHS.Elements.begin();

    // Check if both bitmaps are empty.
    if (Elements.empty() && RHS.Elements.empty())
      return false;

    // Loop through, intersecting as we go, erasing elements when necessary.
    while (Iter2 != RHS.Elements.end()) {
      if (Iter1 == Elements.end()) {
        CurrElementIter = Elements.begin();
        return changed;
      }

      if (Iter1->index() > Iter2->index()) {
        ++Iter2;
      } else if (Iter1->index() == Iter2->index()) {
        bool BecameZero;
        changed |= Iter1->intersectWith(*Iter2, BecameZero);
        if (BecameZero) {
          ElementListIter IterTmp = Iter1;
          ++Iter1;
          Elements.erase(IterTmp);
        } else {
          ++Iter1;
        }
        ++Iter2;
      } else {
        ElementListIter IterTmp = Iter1;
        ++Iter1;
        Elements.erase(IterTmp);
        changed = true;
      }
    }
    if (Iter1 != Elements.end()) {
      Elements.erase(Iter1, Elements.end());
      changed = true;
    }
    CurrElementIter = Elements.begin();
    return changed;
  }

  // Intersect our bitmap with the complement of the RHS and return true
  // if ours changed.