If json_int_t is known to be at least 64-bit, can we perhaps limit ourselves to the following?

#define JSON_INT_MAX 9223372036854775807

But then I'm not even sure such a large integer is valid in C89...

I think the point of allowing the user to define json_int_t is that it could be defined smaller than 64 bits (or larger) depending on the user's needs. Perhaps we should merge #102 first.

Actually, it's best to let end users define JSON_INT_MAX themselves in a non-portable way if needed, just like json_int_t.

That shouldn't be difficult to achieve. Though, with all this compile time customizability, I will want to add some way to detect mismatched compile settings as early as possible, worst case scenario being runtime asserts in debug builds.

See #115.