It's the same way that good grammar is only one of the skills involved in writing a great novel. Some scholars really grok grammar, and are excellent at teaching it, yet they haven't written great novels. I'm thinking of William Strunk Jr (of "The Elements of Style" fame), for example.
Not sure that Strunk, or the successor Strunk and White, are good examples here; they didn't "really grok grammar", in fact, they were pretty bad at both understanding it and teaching it, and their advice consists of a lot of incorrect information and vague platitudes. E. B. White was actually a good writer, but much of his writing violates the prescriptions in The Elements of Style.
Geoff Pullum has a good rant on the subject, if you want more detail: https://chronicle.com/article/50-Years-of-Stupid-Grammar/254...
So, this is exactly why it's an interesting question to test if the suggestions in the "Effective C++" series are actually good suggestions, or are just someone expounding rules that sound good in theory but don't actually help in practice.
That said, I think he does a good job being even-handed. For example, his chapter on auto covers both advantages and pathological cases, and goes on to say:
First, take a deep breath and relax. auto is an option, not a mandate. If, in your professional judgment, your code will be clearer or more maintainable or in some other way better by using explicit type declarations, you’re free to continue using them. But bear in mind that C++ breaks no new ground in adopting what is generally known in the programming languages world as type inference.
So he is not excessively proscriptive.
As for Carmack:
I sort of meandered into C++ with Doom 3 – I was an experienced C programmer with OOP background from NeXT’s Objective-C, so I just started writing C++ without any proper study of usage and idiom. In retrospect, I very much wish I had read Effective C++ and some other material. A couple of the other programmers had prior C++ experience, but they mostly followed the stylistic choices I set.
Like in sport, coaches are good at pointing to particular aspects of someone's game, but were not necessarily great at putting it all together on the field. You find there's different coaches for attacking, defending, etc.
They all tend to have tried playing at some level, however. Even Mourinho was a senior player for a short while.
I suspect programming gurus are no different. They may get very good at shouting RAII or SFINAE at you, without being great at executing it in a large project.
That being said, I have worked on large scale C++ projects, with a lot of people smarter than me, and the biggest criticism of Meyers' books and advice would be "necessary but not sufficient". I can't, off the top of my head, think of anything he recommends that would have been controversial amongst my peers.
My own personal feeling is that books like these can be invaluable for people starting out in the industry. It gives you a reference point to relate to. If he can explain things well and people can understand his writing, then it can be useful even if the person isn't the best living coder on earth.
At some point in your development, you need to branch out from what people are saying in books and start to form your own opinions. You have to start questioning what the "experts" are saying and try to experiment with other techniques. It is frustrating when people hang on to certain ideas just because a famous author said it. Sometimes it holds us back. It doesn't make their contribution any less valuable, though, because at least newbies are getting to a certain level due to the well written books.
My recollection of the older books is that they covered "best practices," and ignoring them may have been bad style, but the code would still be technically correct. Quite a few are still style issues, but it's important to recognize the difference before deciding to ignore them :-)
What I appreciate is that most of what he says (via GotW or the books) comes with the rationale and a code snippet instead of a blind assertion that this is The True Way.
Do engineers know the ins and outs of concrete and rebar? Or do they offload that knowledge onto manufacturers? But programmers can't offload anything onto the language creator or they aren't real programmers.
I'm glad for all the work the SBCL and GHC teams put onto their languages so I can use their abstractions without needing to know the ins and outs of performance optimization. Maybe one day you'll find a language you like that allows you to focus more on your problem domain and less on its traps, idiossyncrasies and inadequacies.
Macho man! ... Maybe one day you'll find a language ...
Your tone is really shitty, and it's made worse by the fact that you're being shitty toward some imaginary strawman you've put in my place. For what it's worth: I greatly value good abstractions, I think appropriate high-level languages should be used whenever there's not a good reason to use low-level languages, I think leakier abstractions are shittier abstractions, I think C++ is full of the leakiest of abstractions, and I think Haskell and lisps are great. I know you're really eager to shit on others because you think you've achieved some kind of higher level consciousness, but you should probably work on your knee-jerk reactions.
Well, I read one of his articles which you can find here: http://www.artima.com/cppsource/top_cpp_books.html
In it, he writes about his role with C++:
"I’ll begin with what many of you will find an unredeemably damning confession: I have not written production software in over 20 years, and I have never written production software in C++. Nope, not ever. Furthermore, I’ve never even tried to write production software in C++, so not only am I not a real C++ developer, I’m not even a wannabe. Counterbalancing this slightly is the fact that I did write research software in C++ during my graduate school years (1985-1993), but even that was small (a few thousand lines) single-developer to-be-thrown-away-quickly stuff. And since striking out as a consultant over a dozen years ago, my C++ programming has been limited to toy “let’s see how this works” (or, sometimes, “let’s see how many compilers this breaks”) programs, typically programs that fit in a single file. (make? Who needs stinkin’ make?) My living is based on C++, but it’s not by virtue of the programs I write in it.
It’s not by virtue of any intimate association with the language’s standardization, either, because I’ve never been a member of the C++ standardization committee, I’ve never been on the committee’s mailing lists, and I’ve never attended any standardization meetings. My knowledge of the inner workings of the committee—including the things that have had a significant impact on it—is based on what I’ve read and heard from others. This means that I may be ignorant of important forces that shaped C++ as we know it, because those forces may have been felt only within the committee.
Given that I don’t really use C++, nor do I help specify it, you might wonder what I do do. Fundamentally, I study C++ and its application. I gather as much information as I can about the language and its use (from books, magazines, newsgroups, email and face-to-face conversations with developers and members of the standardization committee, experiments with toy programs I write, etc.), organize and analyze what I find, then I package my findings in concentrated form (e.g., books, magazine articles, technical presentations, etc.) for consumption for people like you—people who do use the language. Your job is to employ C++ as a tool to write useful software. My job is to discover and package the information you need to best apply that tool.
I like to think of myself as an outside observer, not too deeply steeped in the day-to-day travails of programmers and not too keenly focused on the minutiae of standardization, yet familiar with both. This series of articles, then, summarizes what this self-proclaimed outside observer thinks have been the most important contributions to C++ since its inception...."
In my opinion you should make your mind about what the class does: is it mutable? then don't use it with const. Unfortunately, you are still required to use const in many places: copy constructors and operators, for example. However, you can still choose to minimize the use of const, and avoid it whenever possible.
I would say that constness is a massive boon so I use it on the vast majority of declarations. It reduces cognitive load by being able to assume that variables are not going to change.
include <iostream>
void foo(const int& a, int& b)
{
std::cout << "a: " << a << std::endl;
std::cout << "b: " << b << std::endl;
++b;
std::cout << "a: " << a << std::endl;
std::cout << "b: " << b << std::endl;
}
int main() {
int a = 1;
foo(a, a);
}
A const reference guarantees to the caller that the callee won't modify the object, not to the callee that the object won't be modified.
It's to be expect that we can change a-through-&b, but not a-through-&a in foo.
You either need to be very strict about creating non-const references to objects, or you need to enforce immutability at the class level. Unfortunately the latter has all sorts of other practical problems, often including efficiency trade-offs or awkward APIs.
And this is exactly why const means pretty close to nothing. Compilers can't enforce it in so many situations that it is almost like the "auto" keyword in pre-C++11 times.
If you want the compiler to actually enforce safety properties of the language, use a language like Haskell or Rust.
In addition, to enforce immutability in C++, you have to disable copy/move constructors and assignment operators, which removes much benefit of using values instead of references.
But const cannot guarantee this, because it can be cast away so easily. This could be true just for your own code, but then it is you who is responsible for maintaining the immutability, not the compiler.
By this logic, none of the static type checks in C++ is of any use, since they can be cast away easily as well.
Those who cannot do or teach, write books.
( And use the fame derived from them to get consulting gigs. )
As a programmer, I'm suspicious when people have opinions and give advice but never showed me more than snippets of code. Like a master tailor that wouldn't sew. How come he gets that much recognition and respect?
I would be much more inclined into accepting advice from someone like, say, Carmack, that has successful projects in C++ under his belt. (Many people consider Doom 3's code beautiful C++, yet, the choices made there are very controversial, and far from "modern".)
I also put Bjarne Stroustrup in the same category.
What do you think?