Support boost::multiprecision::cpp_int as IntermediateType about fpm

[MikeLankamp]

I've noticed that issue as well. I think the is_integral assertion also fails for boost::multiprecision.

Edit: I see you're asking about IntermediateType, not BaseType. Yes, then the is_signed check is all that matters. My comment is basically #8.

I've tried to think of better alternatives, but there's really no good way to verify that a type acts like an integer. I don't think even C++20's concepts allow you to test that e.g. T{0} / 2 == T{0} (a property usually true for integers). In other words, C++ has no static "duck-typing" checks.

There may be no option than removing those checks, adding proper documentation and hoping people only use integer-like types. If you (or anyone) has other alternatives, I'm all ears.

And I'm glad to hear you find this library useful! The trigonometry stuff might be improvable in accuracy or performance, but that requires a level of knowledge of math I don't posses :)

[mdragon159]

As a side note, this isn't a big deal/high priority for me at all as I just need to comment out the relevant static_assert (and very carefully test). Unfortunately this does prevent me from using this library directly as a git submodule, but that's not a significant concern at all.

On a different note, thank you very very much for making this library. It's much easier to use than CNL as well has the trig functionality I needed, plus the various documentation with library comparisons incl. regarding performance made me very comfortable starting to use this library. This is overall saving me a ton of time in making a cross-platform deterministic game with fixed points under the hood. Ty again ^_^