@pirix-gh I hope this PR will suite your standards

I'm investigating your PR to see if this could be applied to all the types

TypeDoc is giving me problems generating the docs when using readonly... They don't support it

Seems like I'll have to add ReadonlyArray to bypass that. For now, till I write a proper doc generator.

Ok, it's not possible to generalize it like I said. But it's now fixed with your changes. Thanks!

(v2.1.5)

Always happy to help!

Feel free to assign me future issues

There's going to be a 3.x update with a few breaking changes. Those will improve type soundness and provide computations that have minimum impact on the global performance. It's a sacrifice that is needed.
The changes concern the Boolean mostly (API change), but will also change (Internally only) a few other types.

When can we expect that version? I will defer my work until then as I use this library extensively now

I don't know for sure. But I'm giving myself a deadline of 5-6 days from now, going to try to rush it though. I'll keep you updated. But as I said, Boolean API will change and only the types returning boolean will change too. The actual boolean is making the lib too heavy, and is being changed to 0 & 1 so that it can be used to build indexed conditional types (thus helping remove the slow extends on predicates).

It will also help to fix types that don't work well on unions, which is a bug. So it's a 2-in-1 update.