[jan-jaap]

You could argue that C++ is still a cfront type library! 

I didn't care so much about the C++ to C translation aspect of it, but at the time I was working on a large code base of scientific simulation software that we supported on Windows, OS/2 (both Watcom compiler), IRIX, HP-UX, Solaris and AIX (usually native compilers, sometimes GCC). All of these compilers had their own moronic deviations from the standards. All of them used different APIs for threading and many other OS primitives. All of them had different implementations of C++ templates or were lacking in various aspects. All were broken in subtle ways that could make them generate incorrect object code from correct source code. Don't get me started on the bugs in early IRIX 6.0 and MIPSpro when targeting a PowerChallenge (it didn't help that very few code was 64 bit clean in those days).

It was a pain is the ass, and often if you fixed something or worked around the limitations of one platform you'd break something on another.

Compilers have come a long way. Adherence to standards has too. And don't forget that many of the tools you take for granted these days like static analyzers, valgrind, CI/CD, version management systems that understand change sets of more than a single file, didn't exist back then or were much much more limited