> nearly 99% of the C standard is in C++

But, one of the annoying habits of WG21 (the C++ committee) is sending stuff to WG14 (the C committee) to have them make it part of their language rather than accept that it's a C++ problem. Even the stupid type qualifiers are actually C++'s fault, K&R doesn't have this abomination but the pre-standard C++ did so too bad now it's in C89.