Let's say that my application uses your library. Great! I code it, it works, and I release it for public consumption.

It get popular, so that Ubuntu packages the application and your library. Millions of people use it.

Now what happens when you release a new version of the library? All of the APIs with 710_foo become 720_foo. Which means that I have to rebuild my application to work with the library. I can't just link to the new version and get the bug fixes.

Even worse, Ubuntu has to rebuild all applications which depend on your library. Every time you release a new version.

This is why no one else puts version numbers into function / struct names. We rely on the C compiler to do type checks at compile time, and we rely on the linker to do symbol checks at run time.

If no one else puts version numbers into function names, it should be a strong hint that you shouldn't do that, either.

Similarly, 80-character symbols / macro names are just too complicated to use / remember. Pretty much no one else does this, either.