+ /* Returns the length of the number in bits, i.e., zero if the number
+ * is zero and otherwise one more than the largest value of bi for
+ * which getBit(bi) returns true. */
+ Index bitLength() const;
+ // Get or set bit number bi, which has value 2^bi.
+ bool getBit(Index bi) const {
+ return (getBlock(bi / N) & (1 << (bi % N))) != 0;
+ }
+ void setBit(Index bi, bool newBit);
+