283   size_t CopySize = Rand(ToSize - ToBeg) + 1;  in CopyPartOf()  local
284   assert(ToBeg + CopySize <= ToSize);  in CopyPartOf()
285   CopySize = std::min(CopySize, FromSize);  in CopyPartOf()
286   size_t FromBeg = Rand(FromSize - CopySize + 1);  in CopyPartOf()
287   assert(FromBeg + CopySize <= FromSize);  in CopyPartOf()
288   memmove(To + ToBeg, From + FromBeg, CopySize);  in CopyPartOf()
300   size_t CopySize = Rand(MaxCopySize) + 1;  in InsertPartOf()  local
301   size_t FromBeg = Rand(FromSize - CopySize + 1);  in InsertPartOf()
302   assert(FromBeg + CopySize <= FromSize);  in InsertPartOf()
304   assert(ToInsertPos + CopySize <= MaxToSize);  in InsertPartOf()
308     memcpy(MutateInPlaceHere.data(), From + FromBeg, CopySize);  in InsertPartOf()
309     memmove(To + ToInsertPos + CopySize, To + ToInsertPos, TailSize);  in InsertPartOf()
310     memmove(To + ToInsertPos, MutateInPlaceHere.data(), CopySize);  in InsertPartOf()
312     memmove(To + ToInsertPos + CopySize, To + ToInsertPos, TailSize);  in InsertPartOf()
313     memmove(To + ToInsertPos, From + FromBeg, CopySize);  in InsertPartOf()
315   return ToSize + CopySize;  in InsertPartOf()