Is C++ usage really declining?

A wonderful interview from the father of C++:

It’s probably not complete nonsense. C++ use appears to be declining in some areas and appears to be on an upswing in other areas. If I had to guess, I’d suspect a net decrease sometime during 2002-2004 and a net increase in 2005-2007, but I doubt anyone really knows. Most of the popular measures basically measures noise and ought to report their findings in decibel rather than “popularity.” Many of the major uses are in infrastructure (telecommunications, banking, embedded systems, etc.) where programmers don’t go to conferences or describe their code in public. Many of the most interesting and important C++ applications are not noticed, they are not for sale to the public as programming products, and their implementation language is never mentioned. Examples are Google and “800″ phone numbers. Had I thought of a “C++ inside” logo in 1985, the programming world might have been different today.

Among the positive signs for C++, I can mention an increase in my email and the number of speaking invitations. At the SDWest conference in March, the C++ track was by far the largest, even without counting the “Super tutorial” that I gave with Herb Sutter; more than 300 people attended that one—up by a factor of two compared to two years ago. These are, of course, personal and subjective measures, but they fit with other information that I get from innumerable sources in the industry (worldwide).

It’s a really big world “out there” and the increase in the number of users of one language does not imply the decrease in the numbers of another. I suspect we have reached the point where if you can count your users to the nearest million, you don’t count as a major language. Similarly, I got into a discussion with some friends about how many billions of lines of C++ code there were “out there.” We concluded that we did not know, but it didn’t require much thought to demonstrate that the plural was appropriate.

One simple thing that confuses many discussions of language use/popularity is the distinction between relative and absolute measures. For example, I say that C++ use is growing when I see user population grow by 200,000 programmers from 3.1M to 3.3M. However, somebody else may claim that “C++ is dying” because it’s “popularity” has dropped from 16 percent to 10 percent of the total number of users. Both claims could be simultaneously true as the number of programmers continues to grow and especially as what is considered to be programming continues to change. I think that C++ is more than holding its own in its traditional core domains, such as infrastructure, systems programming, embedded systems, and applications with serious time and/or space constraints. It never was dominant for scripting web applications.

Most of the popularity measures seem to measure buzz/noise, which is basically counting mentions on the web. That’s potentially very misleading. Ten people learning a scripting language will make much more noise than a thousand full time programmers using C++, especially if the thousand C++ programmers are working on a project crucial to a company—such programmers typically don’t post and are often not allowed to. My worry is that such measures may actually measure the number of novices and thus be an indication of a worsening shortage of C++ programmers. Worse, managers and academics may incautiously take such figures seriously (as a measure of quality) and become part of a vicious circle.