Make a data.frame with pre-serialized integer64 columnsSource:
integer64 types do not
dput wells with
hexNumeric. Instead, we serialize and
then unserialize them cf truecluster/bit64#27 and store that as one expression per column
This makes the resulting data.frame awkward, but it will be recorded by
dput in a
way that does get read back in faithfully (so long as the expression isn't quoted).