compat.boost-optional

// boost-endian (byte-order conversion), boost-container-hash (hashing),
// boost-logic (tribool) and boost-align (pointer alignment helpers).
#include <boost/align/align_down.hpp>
#include <boost/align/align_up.hpp>
#include <boost/align/is_aligned.hpp>
#include <boost/container_hash/hash.hpp>
#include <boost/endian/conversion.hpp>
#include <boost/logic/tribool.hpp>

#include <cstdint>
#include <vector>

int main() {
    bool ok = true;

    // endian: reversing is an involution with byte-exact results.
    {
        std::uint32_t x = 0x01020304u;
        ok = ok && boost::endian::endian_reverse(x) == 0x04030201u;
        ok = ok &&
             boost::endian::endian_reverse(boost::endian::endian_reverse(x)) == x;
    }
// …