Some compilers (eg. MSVC) still require inclusion of <ciso646>
in order to import named operator keywords.
It is easier to stick with traditional punctuators.
Phew, this was painful. Turns out most hints out there on how to use the
Boost serialization iterators are wrong. Here's why:
transform_width<6, 8>
needs an input stream of length: common multiple of 6 and 8.
That is, the padding needs to happen _before_ using the provided
iterators, otherwise the behavior is undefined!
See: http://www.boost.org/doc/libs/1_60_0/boost/archive/iterators/transform_width.hpp
Thanks @mokob for pointing that out to me!
We also need to manually add as many padding chars "=" to the encoded
result as many bytes we had to append to the input to conform to the
rule above.
Decoding then knows the number of padding chars by counting for "=" and
then using it in order to split off the last bytes from the decoded
result.
