What makes C++ FFI painful?

Hi devs, Pardon me for the naïve question. I know that C++ FFI is *hard* in Haskell. From the perspective of an end-user I have heard that `text`'s new UTF-8 validation caused problems when released, as it relied on C++ code, but I never had any problems with it personally. From the GHC  perspective, what makes C++ a difficult language to interface with? Cheers, Hécate -- Hécate ✨ 🐦: @TechnoEmpress IRC: Hecate WWW: https://glitchbra.in RUN: BSD