Boost dynamic_bitset - put an integer value into a range of bits

问题

I have a 7-byte/56-bit bitset that upon construction sets the first bit to one:

boost::dynamic_bitset<> b(56, 1);

After construction, I'd like to place an integer value (say 2019) into bits 4 through 15. I'm curious if there is a simple way within boost to do this without bitwise operations? Basically, I want to set a range of bits to an integer value that I know is small enough to fit into those bits. Thanks for any advice.

回答1:

The boost::dynamic_bitset<> offers much less functionality. I think the only possibility is to use an ordinary loop:

template <typename Bitset>
void set_in_range(Bitset& b, unsigned value, int from, int to)
{
  for (int i = from; i < to; ++i, value >>= 1)
    b[i] = (value & 1);
}

boost::dynamic_bitset<> b(56, 1);
set_in_range(b, 2019, 4, 15);

来源：https://stackoverflow.com/questions/9966814/boost-dynamic-bitset-put-an-integer-value-into-a-range-of-bits