Need to check for "MAX_SAFE_*" values.

[JalonSolov]

JSON comes from JavaScript, and JavaScript has limitations on what numbers can be used without hitting problems.

"The JavaScript Number type is double-precision 64-bit binary format IEEE 754 value. There is no integer type. In more recent implementations, JavaScript also supports arbitrarily large integers using the BigInt type."

This means that decoding should probably take a flag as to whether or not to reject numbers outside the "safe" range - basically +/- (2^53)-1.

That said, the JSON format itself has no such limitations, so any size numbers could be allowed, if you're not worried about interoperability.