248   typedef unsigned long BitWord;  typedef
249   using Allocator = AT<BitWord>;
251   enum { BITWORD_SIZE = (unsigned)sizeof(BitWord) * CHAR_BIT };
256   BitWord *Bits;     // Actual bits.
275     BitWord *WordRef;
295         *WordRef |= BitWord(1) << BitPos;
297         *WordRef &= ~(BitWord(1) << BitPos);
302       return ((*WordRef) & (BitWord(1) << BitPos)) ? true : false;
333     std::memcpy(Bits, RHS.Bits, Capacity * sizeof(BitWord));  in BitVectorTmpl()
404     BitWord Copy = Bits[WordPos];  in find_next()
456     Bits[Idx / BITWORD_SIZE] |= BitWord(1) << (Idx % BITWORD_SIZE);  in set()
469       BitWord EMask = 1UL << (E % BITWORD_SIZE);  in set()
470       BitWord IMask = 1UL << (I % BITWORD_SIZE);  in set()
471       BitWord Mask = EMask - IMask;  in set()
476     BitWord PrefixMask = ~0UL << (I % BITWORD_SIZE);  in set()
483     BitWord PostfixMask = (1UL << (E % BITWORD_SIZE)) - 1;  in set()
496     Bits[Idx / BITWORD_SIZE] &= ~(BitWord(1) << (Idx % BITWORD_SIZE));  in reset()
509       BitWord EMask = 1UL << (E % BITWORD_SIZE);  in reset()
510       BitWord IMask = 1UL << (I % BITWORD_SIZE);  in reset()
511       BitWord Mask = EMask - IMask;  in reset()
516     BitWord PrefixMask = ~0UL << (I % BITWORD_SIZE);  in reset()
523     BitWord PostfixMask = (1UL << (E % BITWORD_SIZE)) - 1;  in reset()
538     Bits[Idx / BITWORD_SIZE] ^= BitWord(1) << (Idx % BITWORD_SIZE);  in flip()
550     BitWord Mask = BitWord(1) << (Idx % BITWORD_SIZE);
659         std::memcpy(Bits, RHS.Bits, RHSWords * sizeof(BitWord));
674     BitWord *NewBits = Alloc.allocate(Capacity);
675     std::memcpy(NewBits, RHS.Bits, Capacity * sizeof(BitWord));
755       BitWord ExtraBitMask = ~0UL << ExtraBits;
771     std::memcpy(Bits, NewBits, OldCapacity * sizeof(BitWord));  in grow()
778   void init_words(BitWord *B, unsigned NumWords, bool t) {  in init_words()
779     memset(B, 0 - (int)t, NumWords * sizeof(BitWord));  in init_words()
789       BitWord BW = Bits[i];  in applyMask()
796           BW |= BitWord(M) << b;  in applyMask()
798           BW &= ~(BitWord(M) << b);  in applyMask()
807         Bits[i] |= BitWord(M) << b;  in applyMask()
809         Bits[i] &= ~(BitWord(M) << b);  in applyMask()