JSON hash that is platform independent?

[WillemvJ]

I have a brief question, caused by the documentation provided here for the hash function of the library:

https://json.nlohmann.me/api/basic_json/std_hash/

In the example, it is noted that

Output:

hash(null) = 2654435769
...
hash({"hello": "world"}) = 4469488738203676328

Note the output is platform-dependent.

I an confused by this remark. Does it mean that the hash of a certain json object (e.g. one read from a file) will be different on different platforms?

If yes, why would that be? Is there any way to ensure that hashes will be the same when compiling on different platforms, e.g. windows(MSVC) and linux (GCC)?

[nlohmann]

The library uses std::hash under the hood whose results are not guaranteed to be portable.

[WillemvJ]

Ok thanks, that makes sense. I need a platform independent-hash - I will try to convert the json to string and create a platform-independent hash of that string.

[nlohmann]

Feel free to create an MR!