Thanks!

Yes that's exactly what's happening under the hood. I'm definitely looking forward to the constexpr operator being accepted!

Thanks for catching that!

I discuss the approach more in depth here:

http://saadahmad.ca/detecting-evaluation-context-inside-cons...

So would a valid tl;dr be, "modify the compiled program to catch any invocations not evaluated at compile time and make them return the correct value?"

That is basically it :)