John D Cook: I disagree with Linus Torvalds about C++ (2009)

I heard about this note from Linus Torvalds from David Wolever yesterday. Here’s Torvald’s opinion of C++.

C++ is a horrible language. It’s made more horrible by the fact that a lot of substandard programmers use it, to the point where it’s much much easier to generate total and utter crap with it. Quite frankly, even if the choice of C were to do *nothing* but keep the C++ programmers out, that in itself would be a huge reason to use C.

Well, I’m nowhere near as talented a programmer as Linus Torvalds, but I totally disagree with him. If it’s easy to generate crap in a relatively high-level and type-safe language like C++, then it must be child’s play to generate crap in C. It’s not fair to compare world-class C programmers like Torvalds and his peers to average C++ programmers. Either compare the best with the best or compare the average with the average . Comparing the best with the best isn’t very interesting. I imagine gurus like Bjarne Stroustrup and Herb Sutter can write C++ as skillfully as Linus Torvalds writes C, though that is an almost pointless comparison. Comparing average programmers in each language is more important, and I don’t believe C would come out on top in such a comparison.

Torvalds talks about “STL and Boost and other total and utter crap.” A great deal of thought has gone into the STL and to Boost by some very smart people over the course of several years. Their work has been reviewed by countless peers. A typical C or C++ programmer simply will not write anything more efficient or more robust than the methods in these libraries if they decide to roll their own.

Torvalds goes on to say

In other words, the only way to do good, efficient, and system-level and portable C++ ends up to limit yourself to all the things that are basically available in C.

I’ve had the opposite experience. I’d say that anyone wanting to write a large C program ends up reinventing large parts of C++ and doing it poorly. The features added to C to form C++ were added for good reasons. For example, once you’ve allocated and de-allocated C struct s a few times, you realize it would be good to have functions to do this allocation and de-allocation. You basically end up re-inventing C++ constructors and destructors. But you end up with something totally sui generis . There’s no compiler support for the conventions you’ve created. No one can read about your home-grown constructors and destructors in a book. And you probably have not thought about as many contingencies as the members of the C++ standards committee have thought of.

I disagree that writing projects in C keeps out inferior C++ programmers who are too lazy to write C. One could as easily argue the opposite, that C is for programmers too lazy to learn C++. Neither argument is fair, but I think there is at least as much validity to the latter as there is to the former. I think there may be a sort of bimodal distribution of C programmer talent: some of the best and some of the worst programmers use C but for different reasons.

I do not claim that C++ is perfect, but I’ve never had any desire to go back to C after I moved to C++ many years ago. I’ll grant that I’m not writing my own operating system, but neither are the vast majority of programmers. For my work, C++ is as low-level as I care to go.