> So if you think one should know, you probably should not need this function > at all.
That's right. I'd also say that since the aim is to have better interoperability between systems, mixed seems judicious. For example, a bool or a null can occur. > Btw. is_primitive() was not a thing last time I looked. It would be great > though to have the combined test of is_scalar() and is_null() in a single > function call. I like the idea. Would it have its place in this RFC? I feel like it could with a separate vote, but maybe this would require its own RFC.
