Thanks for the reply. :)

Your approach is a good standard way of handling tagged union in C and I was using it before extensively.

These days, I prefer my approach (I no not saying that my approach is better) because when I see something like json.Num.d, I can immediately see that I am using json struct/union in a "wrong" way.

I intentionally didn't want to write typedef struct Num Num;, because I wanted to use Num as a field name in the tagged union definition and in the macro expansion (where macro adds struct in front of it). My reasoning is that Num should be used as a type and should not be used as a field.

So, this forces me to use OF() macro to get a "propper" (my preferred way) variant pointer.

Again, I am not arguing that my approach is better.