1148   OS << " updater with gap = " << (ReadI - WriteI)  in print()
1151   for (const auto &S : make_range(LR->begin(), WriteI))  in print()
1195     WriteI = ReadI = LR->begin();  in add()
1205     if (ReadI != WriteI)  in add()
1208     if (ReadI == WriteI)  in add()
1209       ReadI = WriteI = LR->find(Seg.start);  in add()
1212         *WriteI++ = *ReadI++;  in add()
1242   if (WriteI != LR->begin() && coalescable(WriteI[-1], Seg)) {  in add()
1243     WriteI[-1].end = std::max(WriteI[-1].end, Seg.end);  in add()
1248   if (WriteI != ReadI) {  in add()
1249     *WriteI++ = Seg;  in add()
1254   if (WriteI == E) {  in add()
1256     WriteI = ReadI = LR->end();  in add()
1265   size_t GapSize = ReadI - WriteI;  in mergeSpills()
1267   LiveRange::iterator Src = WriteI;  in mergeSpills()
1273   WriteI = Dst;  in mergeSpills()
1296     LR->segments.erase(WriteI, ReadI);  in flush()
1302   size_t GapSize = ReadI - WriteI;  in flush()
1305     size_t WritePos = WriteI - LR->begin();  in flush()
1308     WriteI = LR->begin() + WritePos;  in flush()
1311     LR->segments.erase(WriteI + Spills.size(), ReadI);  in flush()
1313   ReadI = WriteI + Spills.size();  in flush()