21st Century C

Chapter 8. Obstacles and Opportunity

There’s no C Foundation paying me to advocate the language, and this book is not a sales pitch dressed up as a tutorial, so I can write freely about C’s problems. The bits here are too valuable to be in the don’t-bother category under which so many of the items in the previous chapter fall, but they also come with cautions about the historic cruft that made sense at the time and is now just a mess.

• C’s macro facilities are simple but still pack in a lot of little exceptions.

• The usage of the static keyword is at this point painfully confusing, though in the end, it will give us a nice alternative to elaborate macros. Its complement in certain senses, the extern keyword, also gives us enough rope with which to hang ourselves.

• The const keyword fits this chapter because it is too useful to not use, but it has oddities in its specification in the standard and in its implementation in common compilers.

Cultivate Robust and Flourishing Macros

Chapter 10 will present several options for making the user interface to your library friendlier and less error-inviting, and will rely heavily on macros to do it.

I read a lot of people who say that macros are themselves invitations for errors and should be avoided, but those people don’t advise that you shouldn’t use NULL, isalpha, isfinite, assert, type-generic math like log, sin, cos, pow, and so on, or any of the dozens of other facilities defined by the GNU standard library via macros. Those are well-written, ...