Binary Serialization of std::bitset

Question

std::bitset has a to_string() method for serializing as a char-based string of 1s and 0s. Obviously, this us

Answer 1

Answering my own question for completeness.

Apparently, there is no simple and portable way of doing this.

For simplicity (though not efficiency), I ended up using to_string, and then creating consecutive 32-bit bitsets from all 32-bit chunks of the string (and the remainder*), and using to_ulong on each of these to collect the bits into a binary buffer.
This approach leaves the bit-twiddling to the STL itself, though it is probably not the most efficient way to do this.

* Note that since std::bitset is templated on the total bit-count, the remainder bitset needs to use some simple template meta-programming arithmetic.