The FQA FAQ

Part of C++ FQA Lite

This page contains answers to Frequently Asked Questions about the C++ Frequently Questioned Answers. Which is a pretty bad case of having too many levels of indirection. The FQA FAQ is based on a semantical histogram of about a couple of hundred messages, some of which were supposed to be for me, and some others - for all the happy Web 2.0 users out there. Questions that were asked several times made it to the list (there was no lower bound on the quality though).

If you want to question the facts in the FQA, there's a separate page for that. Send me e-mail, and if you correct a factual error, I'll add your stuff.

Most of the questions here manifest negative attitude. Let me assure you that I got plenty of positive feedback, too, but, somewhat naturally, it rarely comes in the form of a question. And I am not going to add fake FAQs to make the subject look better the way C++ FAQ does.

It looks like a bunch of random points, what are you trying to say?

Read Defective C++ if you're looking for a summary. The Q&A sections follow the structure of the C++ FAQ, and talk about things on varying scales and of different importance.

I want to ask you something and get an answer, what should I do?

Send me mail.

Here's how it works. Publishing stuff makes sense. Face to face conversations and e-mail conversations make sense. Conversations in the form of articles replying to other articles make sense some of the time. Comment thread conversations are futile. Special case: Usenet conversations are futile. If they are moderated, they are futile and (almost) polite.

An example of a futile, (almost) polite discussion of the C++ FQA can be found in this comp.lang.c++.moderated thread. For some reason, several people well-known in the C++ community decided to have a bunch of off-topic arguments in that thread (like how bad it is that some obscure features are going into C++0x and other obscure features aren't). Off-topic and futile, but amusing and (almost) polite.

Is there any alternative to C++?

Yes, there's plenty. And no, there's none.

As the C++ FAQ correctly points out, there's a key issue with choosing a programming language - availability. That is, stuff that already exists that your project depends upon. For example, you may need C++ libraries which have no alternative in other languages (today, in practice - not in the future, in theory). The project can already have lots of C++ code in it, and rewriting it in another language is most often not an option. Note how you can substitute COBOL for C++ in this paragraph and the claims will still hold.

However, if you're asking about the programming language by itself, then C++ is never the best choice. In particular, use languages with safe execution and automatic memory management whenever possible, because that greatly increases the speed of development and solves many practical stability and security problems. There's plenty of languages in that family. If you really need the speed badly enough to settle for unsafe execution, you still have better options than C++ - for example, D, Objective-C, and plain old C, a good snapshot of the language taken before the postfix increment (Clarification: I know that many things were back-ported from C++ to ANSI C, you language lawyer). You can also mix many programming languages fairly easily.

Of course you are forced to use C++ quite frequently, and in this sense there may be no alternative to it. I use C++ a lot. I wouldn't write the FQA if I didn't. But since I've stopped using it when I don't have to, many things became really easy. Try it. Stop being a die-hard C++ weenie that does simple throwaway text processing in C++ and calls the compiled programs "scripts". This behaviorial pattern yields suboptimal results. And if you really need to use C++, make sure you know its problems, and don't blindly trust the recommendations of the C++ overlords.

Can't the problems you mention be solved by proper design / project management?

They can. Theoretically. It will still cost more than not having to solve these problems in the first place. You may not realize it, because you're fairly good. The thing is that your ability to juggle lots and lots of things in your head yields the best results when these things are not entirely worthless. Without having to work around C++, you'll get more done. But the bottom line is that you can have good C++ code, with most problems of C++ not manifesting themselves. If everybody on the team is really good at C++, and has a practical approach and lots of experience, and your schedules aren't too tight.

This last statement rarely holds, especially for larger projects. The issue with real-world schedules and having no time to fight C++ in addition to the real problems is probably clear. The practical approach and the experience are relatively obvious, too. People who prefer complicated solutions because it demonstrates their skills and/or try to use their language naively and "naturally" can cause lots of damage if their weapon is C++; the FQA has lots of details on that one. The strangest thing for most strong programmers is - if someone is not very good at C++ (or whatever your project is written in, for that matter), why do you want them on your team anyway?

This is really important, and took me some time to understand - it's one of the several things that go against the grain of the training most programmers undergo. Well, let's look at an example. We have this guy who is really good at physics, or statistics, or economics, or AI/machine learning, or genetics - whatever your domain is. And he can program. He's not an expert programmer, but he's brilliant, and the code turns out pretty neat, at the semantical level, although admittedly he prints objects to cout with printSomething functions - pretty lame, that. We can have him on board, happily coding away. We can hire him and let a strong programmer talk to him, convert his ideas to code and bring back whatever the machine has to say when it runs, iteratively. Or we can send the clueless PhD away and hire another SFINAE expert. It's your call. What will it be?

Let's move on. What about the young, bright, responsible but inexperienced type, constantly looking for the most urgent problem and rushing to fight it? What about the amazing coder, who can only be seen coding if you put a camera in his office and play the recording in slow motion - most of the time he's surfing non-productive sites, except somehow all that stuff that scares the heck out of other people gets done in no time? What about the super-orderly, super-smart person, who can do anything you ask for, precisely and quickly, but just happens to be a newbie in your language, and will have no time to become an expert? Too bad all these people are not language lawyers, and can wreak havoc in C++. Would you have them on your team, or would you send them over to your competitor?

The programming language is not the main theme in programming. Therefore, using a language which doesn't require expertise from all users can help you utilize your human resources better, as the business-friendly-looking FAQ would say.

But I already know C++, and so do many others. Isn't learning new languages hard?

No. And the amazing part is that you'll tell me that yourself. Many times I heard something like "C'mon, this language is trivial and has nothing new, why would I invest all that energy into learning it?" Prediction: the next step in the evolution of the brain will be a built-in consistency checker.

Clarification: learning new libraries can take time, and rewriting old code is not a sane option in most cases. I'm talking about new code, not old code.

And, you'll be surprised how easy most languages are compared to C++. You can stay extremely ignorant about how they work and they won't bite you, for years. I tested this one myself since I was very curious. Perhaps I'll write about it some time.

Not only are most languages easier to learn than C++ - they're easier to use, too. Especially the higher-level ones. You can get interesting work done in no time. You'll think differently about things. The meaning of "design" changes. For instance, hardware hackers call the code describing the hardware "design". "Compile the design". In C++, they usually call the structure of the definitions (classes, functions, templates) "design". At a higher level, you can call the details of how the functionality is specified "design"; writing the code and connecting the pieces is easy enough to be called "implementation details". I'm not really good with this sort of terminology, but it's something like that.

Why are you writing in such an emotional way?

Am not! This is the sanitized, calm and rational version. Do you have any idea how much editing it took?

Seriously, let's examine the breakdown of the potential FQA readers. People who hate C++ will be entertained by the rants, which is not the main purpose, but is a good thing. Some of the people who love C++ can be offended, but would they really feel otherwise if I used different language? And why do they read something having such a title - is this some kind of informational masochism, and how am I responsible for it, anyway?

And now we reach the most important subset of the readers - the ones working with C++ and having their doubts. What's a bigger risk: to scare them with overly aggressive style, or to put them to sleep? Note that the thing that really counts is the information, not the style. Yes, sir, that would be always, and you ought to learn this or else you'll go extinct in no time. Therefore some of the people who won't be able to extract the information from the text because of the style have critical flaws in their thinking, and I don't mind losing this part of the audience. Especially considering the fact that any technical document is an excellent cure for insomnia, and the people who entertain themselves reading RFCs are a tiny minority of the population I'd like to talk to. So the sleeping risk has to be minimized first. This is called risk management, as everybody who was forced to study a braindead Methodology-related document during their career will readily tell you.

By the way, have you seen the FAQ? The FQA is way more vegetarian in many aspects. In particular, the FAQ labels groups of people as techie weenies endangering the interests of their employers, and in general talks a lot about the (bogus) business aspect of the issues. As if you can cut costs by fiddling with syntax and in general have your enterprise thrive by applying a bunch of C++ coding tricks. This crosses the red line as far as I'm concerned. As one of my early reviewers told me in a private message when I asked about my style, many of the FAQ's claims are close to attempts at brainwashing, and therefore my replies are justified. I don't know if he's right at the bottom line, but his message has a special place in my heart.

You are not very objective, are you?

No - it's your job. Do stuff, read stuff, think and make up your mind. Have you actually selected an entity which you think of as "objective"? This is like having a slave port in your brain.

There's plenty of material praising C++ and covering up its deficiencies with unbelievable excuses and broken "solutions". There aren't many sources debunking this material, and for a good reason - there's no money in it. And then the C++ FAQ, which the FQA is based upon, is not at all objective, either.

Can anybody explain me why the FQA should be "objective"? And just what does "objective" mean here? Should I list a plethora of broken workarounds for each mentioned C++ misfeature? Or should I say that many people don't think it's a problem each time I raise a problem? I sincerely and honestly don't get it.

You don't know C++ very well, do you?

If you have valid counter arguments, shoot. I don't feel like demonstrating my C++ skills, or anything else for that matter, to strangers who weren't even taught to be polite.

If this issue is important to you, browse the FQA. You'll find out that I'm aware of RAII, SFINAE, C++0x and just about every other idiotic C++-related acronym you wish to inform me about.

You're clearly into "managed environments", who cares what you think about C++, which has different goals?

They've discovered some time ago that you are supposed to refer to whatever the person says, not the person, to make a valid argument.

I've done lots of low-level work. Real time, interrupts, context switching and process migration, CPUs with small address spaces, 2-digit numbers of processors with shared memory and incoherent caches and local memories, locating and working around hardware bugs, these sorts of things. In C++. Yes, I also worked with managed environments, that part is based on my personal experience, too.

When I say that safe execution is safer than unsafe execution, you can trust me. Do you always prefer credentials to logic? Pretty risky, that.

Why do you complain when C++ lets you do bad things? The language is not your nanny.

I don't really complain about that, you probably took something out of a more complicated context. And check the previous answer, tough guy.

C++ is just a tool. Have you hurt yourself with a big nasty hammer, little baby?

C++ isn't just a tool, it's a language. Languages have different dynamics than tools. And I love you, too.

Are you a troll?

No, I'm a Turing-complete mammal just like you. Trolls are a different species. Biologists inform us that trolls are characterized by the use of flame baits. A dictionary further enlightens us, explaining that a bait is "food or other lure placed on a hook or in a trap and used in the taking of fish, birds, or other animals".

Now, the key insight is that for a troll to survive, it has to use cost-effective baits. That is, the bait should be significantly cheaper than the food, or else the troll will go bankrupt.

Of course, your not-so-well-thought-out emotional response counts as a medium-sized piece of a fish, a bird, or some other animal. But let me assure you, the FQA is way costlier and thus makes a lousy bait. Try doing something like this, and you'll realize that a troll will not pick this path to ensure its survival.

Oh, and I also sign with my real name. Do you do that, too, or is it cooluser35? Humans don't have names like that, you know. And what's that hair doing on your ears?

Don't you know that C++0x will fix all those problems?

I've seen TR1, and my expectations are low. Anyway, the FQA doesn't discuss the future of C++, only its present, and even that is mostly limited to the stuff from the C++ FAQ (that's why we don't talk about implicit casting and overload resolution too much here). So you'll either have to wait for C++0x to materialize (I promise to add a special section when it's adopted), or you can persuade Marshall Cline to add a C++0x section to the FAQ, and I'll see what I can do.

But you could do this to any language. Doesn't it make the whole thing meaningless?

Well, nobody did this to other languages, not on this scale anyhow. The difference in our opinions is that you're saying that I'm special, and I'm saying C++ is special. There are more programmers than there are programming languages, so statistically my argument has better chances to be correct (not; we don't know anything about the distribution of anything, so never mind).

Well, your argument is shaky, too. How about getting some empirical data? Try to write this kind of thing about some other popular language, start with something like "Defective C++" and try to show that whatever you're trying to do with this language just doesn't work. I think your argument will fall apart.

Don't try to discuss it with me - you have nothing to say about the actual reasoning in the FQA, so it's all worthless. I'm just trying to trick you into doing some creative writing. Maybe commenters will show up - you'll discover lots of things about yourself at that point.

All those C++ users and overlords can't be wrong, can they? Why should I believe you?

This sort of thinking will get you in trouble, since it's recursive and it has no termination condition. Very large groups of people with the usual subset of those having impressive credentials are known to have been wrong for very long periods of time (the flat Earth issue comes to mind; these people weren't stupid, mind you, "wrong" and "stupid" is not the same thing). Supposing you are in a group of people who are wrong right now, how do you plan to find it out using your kind of thinking?

You are not supposed to believe me; you're supposed to believe what I say, or not, depending on whether it makes sense. If you feel an urge to discuss this, keep in mind that I don't really care to convince you. I want to talk to people who are likely to start new software projects, with an emphasis on "new". And I don't think you can produce anything "new" in any significant sense before you change your attitude, because new things are by definition not backed up by large groups of supporters, so how would you know what to do?

(John Millikin: Most educated people from Aristotle onward believed Earth to be round, and Eratosthenes measured its circumference rather accurately. Examples in which educated people were wildly incorrect en mass include Humorism and Geocentrism.)

Do you even realize that C++ was shaped by various goals and trade-offs? How can you judge it otherwise?

I'm aware of the trade-offs and goals. If you identify with the language designer, that's very noble of you. I am a language user. I care about getting work done. In other languages, it's way easier for me than it is in C++, and many people feel that way. Of course you are free to misattribute that to my incompetence in the area of C++, computing in general or whatever, and (independently of that) keep having fun with C++.

By the way, I don't try to make you stop using C++, and nowhere in the FQA do I say anything derogatory about people who use C++ in general. Do what you like. People who think this is obvious: sorry. We're not alone on this planet.

Why do you use complicated libraries like boost if they don't make your life easier, and isn't it your fault?

What makes you think I use them? I have no idea why they keep asking that. It looks like people try to build a model of the personality behind the text instead of a model of what the text says. Is it really that helpful?

If you try to make your C++ code simple and easy to follow, I might even enjoy working with you some day.

Why not quit whining and find a better job where there's no C++?

I find my job very interesting. The programming languages you get to use are not at all the most important part of the job, it's what you get to do that counts.

I do try to minimize my use of C++; I try to only deal with it when I help others out of trouble.

And thanks for your genuine interest in my career! I hope you're all right, too. This whole line of discussion is of course very relevant to the contents of the FQA.

Why don't you get a life?

You typed that at some software weenie Web 2.0 site, didn't you?

C++ is already dead, so isn't the whole purpose of this document to get page views?

Of course I want people to view these pages! People usually write stuff so that other people read it. And what makes your fingers type, may I ask?

Regarding "C++ is dead": if you work on businessy apps, it's possible that you didn't notice that there's a huge market of embedded software. C++ only starts to penetrate it now. Also, google for SystemC (hint: it really should have been "SystemC++"). But there's also lots of new code in C++ outside of embedded software or the hardware modeling world. If you use the web to approximate reality, your perspective will be invariably skewed by the people who work with the newest / obscure / most exciting and successful stuff (in random order), since these make the most noise.

And there's lots of people who do most of their work in C++ everywhere, some of them with half a year of experience, and refuse to learn new languages. There are even young people who will refuse to take a job unless they'll get to work in C++.

I don't think people would read this if C++ was acknowledged as a language that people don't write new code in. Would you chase a link to a COBOL FQA?

C++ is not dead, it just smells funny.


Copyright © 2007-2009 Yossi Kreinin
revised 17 October 2009