Explain why C++ and Java serializations differ (in test suite) about flatbuffers HOT 1 CLOSED

From http://google.github.io/flatbuffers/md__internals.html:

"On purpose, the format leaves a lot of details about where exactly things live in memory undefined, e.g. fields in a table can have any order, and objects to some extend can be stored in many orders. This is because the format doesn't need this information to be efficient, and it leaves room for optimization and extension (for example, fields can be packed in a way that is most compact). Instead, the format is defined in terms of offsets and adjacency only."

The C++ .bin file is generated by the JSON parser, which packs the table fields in a different order. Different order can also cause different alignment padding which can even make the size differ by a small amount.

I agree this can be a bit of a surprise, though it is important that implementers of readers/writers understand this issue. I should probably explicitly mention below that paragraph that this can cause different binaries that are all compatible with one another. Any other suggestions welcome.

from flatbuffers.