Modern C++ for systems, part 1

In today’s world, there are two main types of programming languages. Well, there are a lot of main types, depending on how you want to look at it, but you can definitely see a distinction between those languages intended for, say, web applications and operating systems. It’s that distinction that I want to look at here.

For web apps (and most desktop ones), we have plenty of options. JavaScript is becoming more and more common on the desktop, and it’s really the only choice for the web. Then we’ve got the “transpilers” bolted on top of JS, like TypeScript, but those are basically the same thing. And we can also write our user applications in Python, C#, or just about anything else.

On the other side—and this is where it gets interesting, in my opinion—the “systems” side of the equation doesn’t look so rosy. C remains the king, and it’s a king being assaulted from all sides. We constantly see articles and blog posts denigrating the old standby, and wouldn’t you know it? Here’s a new, hip language that can fix all those nasty buffer overflows and input-sanitization problems C has. A while back, it was Go. Now, it’s Rust. Tomorrow, it might be something entirely different, because that’s how fads work. Here today, gone tomorrow, as they say.

A new (or old) challenger

C has its problems, to be sure. Its standard library is lacking, the type system is pretty much a joke, and the whole language requires a discipline in coding that really doesn’t mesh with the fast and loose attitudes of today’s coders. It’s also mature, which hipsters like to translate as “obsolete”, but here that age does come with a cost. Because C has been around so long, because it’s used in so many places, backwards compatibility is a must. And that limits what can be done to improve the language. Variable-length arrays, for instance, are 18 years old at this point, and they still aren’t that widely used.

On the other hand, “user-level” languages such as Python or Ruby tend to be slow. Too slow for the inner workings of a computer, such as on the OS level or in embedded hardware. Even mobile apps might need more power. And while the higher-level languages are more expressive and generally easier to work with, they often lack necessary support for lower-level operations.

Go and Rust are attempts at bridging this gap. By making languages that allow the wide range of operations needed at the lowest levels of a system, while preventing the kinds of simple programming errors a C compiler wouldn’t even notice, they’re supposed to be the new wave in system-level code. But Go doesn’t have four decades of evolution behind it. Rust can’t compile a binary for an 8-bit AVR microcontroller. And neither has the staying power of the venerable C. As soon as something else comes along, Rust coders will chase that next fad. It happened with Ruby, so there’s no reason it can’t happen again.

But what if I told you there’s a language out there that has most of C’s maturity, more modern features, better platform support¹, and the expressive power of a high-level language? Well, if you didn’t read the title of this post, you might be surprised. Honestly, even if you did, you might still be surprised, because who seriously uses C++ nowadays?

Modern world

C++ is about as old as I am. (I’m 33 for the next week or so, and the original Cfront compiler was released in 1985, so not too much difference.) That’s not quite C levels of endurance, but it’s pretty close, and the 32-bit clocks will overflow before most of today’s crop of lower-level languages reach that mark. But that doesn’t mean everything about C++ is three decades out of date.

No, C++ has evolved, and never so much as in 2011. With the release of that version of the standard, so much changed that experienced programmers consider “Modern” C++ to be a whole new language. And I have to agree with them on that. Compared to what we have now, pre-2011 C++ looks and feels ancient, clunky, baroque. Whatever adjectives your favorite hater used in 2003, they were probably accurate. But no more. Today, the language is modern, it’s fresh, and it is much improved. So much improved, in my opinion, that it should be your first choice when you need a programming language that is fast, safe, and expressive. Nowhere else can you get all three.

Why not Java/C#?

C++ often gets compared to Java and C#, especially when talk turns to desktop applications. But on the lower levels, there’s no contest. For one, both Java and C# require a lot of infrastructure. They’re…not exactly lightweight. Look at Android development if you don’t believe me on the Java side. C# is a little bit better, but still nowhere near as efficient in terms of space.

Second, you’re limited in platform support. You can’t very well run Java apps on an iPhone, for instance, and while Microsoft has opened up on .NET in the past few years, it’s still very much a Windows-first ecosystem. And good luck getting either of them on an embedded architecture. (Or an archaic one.)

That’s not to say these aren’t good languages. They have their uses, and each has its own niche. Neither fits well for our purposes, though.

Why not Go/Rust?

Go, Rust, and whatever other hot new ideas are kicking around out there don’t suffer from the problem of being unfit for low levels. After all, they’re made for that purpose, and it’d be silly to make a programming language that didn’t fill its intended role.

However, these lack the maturity of C++, or even Java or C#. They don’t have the massive weight of history, the enormous library of documentation and third-party code and support. Worse, they aren’t really standardized, so you’re basically at the mercy of their developers. Tech companies have a reputation for short attention spans, which means you can’t be sure they won’t stop development tomorrow because they think they’ve come up with something even better. (Ask me about Angular.)

Why C++?

Even if you think some other language works better for your system, I’d still argue that you should give Modern C++ a shot. It can do essentially everything the others can, and that’s not just an argument about what’s Turing-complete. With the additions of C++11, 14, and 17, we’re not talking about the “old” style anymore. You won’t be seeing screen-long type declarations and dizzying levels of bracket nesting. Things are different now, and C++ even has a few features lacking from other popular languages. So give it a shot.

I know I will. Later on, I hope to show you how C++ can replace both the old, dangerous C and the new, limiting languages like Rust. Stay tuned for that.