Method A:
return (the_bitset >> start_bit).to_ulong();
Method B (faster than method A by 100 times on my machine):
unsigned long mask = 1;
unsigned long result = 0;
for (size_t i = start_bit; i < end_bit; ++ i) {
if (the_bitset.test(i))
result |= mask;
mask <<= 1;
}
return result;
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…