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Learning Rust to the point of being productive is 100x easier than C or C++. It's not even funny.

josephg 3y ago
That hasn’t been my experience with it. I found rust significantly harder to learn than C; and this is after I already knew C. (At least - learn rust to the point of feeling productive, and like I wasn’t fighting the borrow checker constantly). Arguably becoming an expert in C means you need to understand all the nuances of undefined behaviour. And that’s a much harder process. But it can happen slowly. Rust preloads all the pain. You essentially can’t write rust at all until you understand rust references, lifetimes (implicit and explicit) and the borrowchecker. The payoff is huge, but I found climbing that mountain to be no joke.
- adrianN 3y ago
  Given the number of CVEs that can be directly attributed to C and C++ you only need to be half-joking to argue that approximately nobody has managed to learn the languages sufficiently to write production code in them.
  - josephg 3y ago
    As uncomfortable as this is to say, the existence of latent security vulnerabilities doesn’t seem to stop people from shipping a lot of apparently working code in C and C++. And I don’t think a lot of those CVEs come from people misunderstanding the languages. As I understand it they mostly come from honest software bugs. C++ makes it easy for honest mistakes by experts to become security nightmares. This is a controversial opinion - but I think the fault is in C and C++ themselves. Not the programmers who need to work even harder such that they stop ever making mistakes.
    - vacuity 3y ago
      Which is why some people push for no longer using C and C++ as much as possible. It's just not feasible to expect the average programmer to avoid all the security pitfalls. Of course, whether Rust is the best option isn't a given.
      - josephg 3y ago
        There aren’t a lot of memory safe options if you want the kind of performance rust offers. Rust is fine, but it’s far from perfect. It’s hard to learn, complex, and the macro and async systems are honestly a bit of a mess. I’m really looking forward to whatever comes after rust. I’m hoping some bright sparks out there manage to make a language with rust’s memory safety but that cleans up some of rust’s rough edges.
        tracker1 3y ago
        To be fair, how many applications really need Rust's level of performance? I mean operating system code and drivers... But, many apps are getting the job done in electron with a browser engine. I like rust, I like the sensibilities. Maybe my experience is too limited to higher level problems though. There's plenty of room for the likes of Go, Java and C# is all I'm getting at.
        josephg 3y ago
        Yeah I think I broadly agree with you. Not many applications need rust's performance. Go, Java, C#, nodejs, python, etc are all great languages. But the software which does need or want "native performance" is incredibly important software. I'd use rust for things like databases, operating systems, web browsers, high performance web servers, network services (samba, ssh), and other "systems" software like that. Most of the lines of code ever written are probably in application code. If you're making a company website, python or C# or whatever is totally fine. But a remarkable proportion of the lines of code your computer actually runs were written in C or C++. Your web server might be in python, but if you use nginx as a proxy - well, thats C++ (I think). Use postgres? C++. Running your software in linux? C. Testing with Chrome? C++. What is python itself written in? I dunno, but I bet its either C or C++. You get the picture. Whether or not rust is a big deal is largely a matter of focus.
  - LtWorf 3y ago
    So you're saying there is no CVE in php, java, go, js, and python?
    - josephg 3y ago
      In their defence, there are entire classes of security bugs that memory safe languages protect you from. A large percentage of the security bugs in Chrome, OpenSSL, iMessage and lots of other apps wouldn’t have happened in any of the languages you listed. Or, almost certainly, in Rust.
      - Xeamek 3y ago
        And how many of such bugs could be prevented with compiler warnings and flags?
        tracker1 3y ago
        If you're going to start writing it testing or C++ like Rust or follow certain guidelines, a lot of them. But if you're going to constrain how you do things, why not use a language that also gives you higher level functionality along the way?
        Xeamek 3y ago
        I agree. My point is that I just feel like "but someone please think of the ̶ ̶c̶h̶i̶l̶d̶r̶e̶n̶ memory safety" argument is over blown. There are ways to eliminate majority of those issues in cpp as well, but people simply don't care. If You want to use Rust because it's just better language - go for it, I do it as well. But let's actually use that as an argument, instead of hiding behind superficial ones
        josephg 3y ago
        > There are ways to eliminate majority of those issues in cpp as well, but people simply don't care. If its that easy, why do Google, Apple, Microsoft and basically everyone else keep making memory safety related bugs? Are they all just idiots? Do you think they just don't care about security? Carmack found C++ static analysis tools found mountains of latent bugs in the quake source code - despite the game running great. Personally I find it a very arrogant statement to claim that memory safety in C++ is easy. If google finds it hard, despite throwing millions each year into the problem, I'm of a mind to believe them.
- zozbot234 3y ago
  > You essentially can’t write rust at all until you understand rust references, lifetimes (implicit and explicit) and the borrowchecker. You can if you're willing to use stuff like .clone() and the interior mutability types. In Rust, you can tell when code has been written to be a bit sloppy because it has that kind of boilerplate. And the compiler checks are a huge help when it comes to refactoring the code and making it cleaner and better-performing.
  - josephg 3y ago
    Eh. If you don’t know how references work in rust, you’ll struggle to use most of the standard library or any 3rd party crates. And if you can’t pass mutable references to functions or iterators there’s a lot of programs that will be hard to write at all. Performance will be pretty rubbish too. You might be able to write some simple programs, but I wouldn’t say you know rust yet, or could really be productive with the language.
- riku_iki 3y ago
  > I found rust significantly harder to learn than C language itself maybe, but you also need to learn ecosystem, libs, build systems, testing. Benchmark could be: how fast you can learn and bootstrap some type of app of your choice: high performance DB or torrent server, etc. > You essentially can’t write rust at all until you understand rust references, lifetimes (implicit and explicit) and the borrowchecker why is that? You can write rust the same way you write C but with nicer syntax, standard lib and build system and more potential to future expansion.
  - josephg 3y ago
    > but you also need to learn ecosystem, libs, build systems, testing. That’s a really good point that I hadn’t thought of. If we include header files, compiling and linking, makefiles and CMake and the mess of dealing with 3rd party libraries in C - well, yeah. All that stuff is probably worse than learning the rust borrow checker. I think I’ve forgotten how horrific that mountain is for beginners because I learned most of it decades ago, while the pain of learning rust is still fresh. > why is that? You can write rust the same way you write C Because I use pointers everywhere in my C code. Rust’s borrow checker simply won’t compile my code if I transliterate it directly from C. There are software patterns which work well in rust with the borrow checker in mind - but they take time to learn and get used to. Until you do, you simply aren’t productive.
    - riku_iki 3y ago
      > Because I use pointers everywhere in my C code. Rust’s borrow checker simply won’t compile my code if I transliterate it directly from C. borrow checker is more relevant to C references I think. For pointers you can use Arc or Rc and don't worry about borrow checker. Disclaimer, I am not a rust or c coder, so my opinion has a high chance to be wrong..
      - josephg 3y ago
        If you want to learn rust, there really isn’t a way to avoid learning lifetimes and the borrow checker. It’s a core part of how the language works. You can probably get partway there with Rc and by cloning stuff everywhere but you’ll still run into borrowck problems. Rc doesn’t turn off the borrow checker. (Nor does unsafe). But then you won’t have the tools to solve your problems. And you also won’t know how to use most of the standard library or any crates. That’s no way to write rust. > Disclaimer, I am not a rust or c coder, so my opinion has a high chance to be wrong.. I’ll take a step back. I hope this is helpful to someone and not patronising. Go and similar languages are memory safe because no matter what go code you write, go runs your program with a GC that makes sure your variables are freed correctly only when it’s safe to do so. Rust’s safety is very different. It comes from checking at compile time that your program is written in a way that obeys a bunch of complex rules. For that to work, you have to write your code very carefully. If you mess up, the compiler doesn’t fix it for you. It just refuses to compile. So you have to write your code with those invariants in mind, or your program won’t build at all. C code generally doesn’t obey any of rust’s rules - for obvious reasons. If you were to just blithely translate C to rust code, the rust compiler will refuse to compile your program because the rules aren’t being followed. To write rust code that the compiler accepts, you need to first learn the borrow checker’s way of seeing the world. Then you need to restructure your code to work in accordance to rust’s rules. And sometimes that’s a super obscure and tricky problem. Weirdly, I think it’d be much easier to go the other way. Any compiling rust program could be translated into a memory safe C program if we had a compiler that did that. (I think). And lots of C programmers say learning rust made them better at C - because rust’s rules genuinely teach you to be more disciplined with memory and show you some clear rules for making C code that’s much less error prone. Not learning the borrow checker is like not learning how objects work in Python. You could write some simple programs. But you’re going to have a bad time, especially if you try to do anything nontrivial, use library code or read anyone else’s programs.
edgyquant 3y ago
Objectively false
pjmlp 3y ago
As someone that speaks legalese, and knows C and C++ relatively well to be productive, if nothing else by knowing them since 1993 and 1994 respectively, also have already written a couple of interesting stuff in Rust, that 100x easier is a bit too much. Specially if we are talking about anything related to graphics programming, or asynchronous programming.

That hasn’t been my experience with it. I found rust significantly harder to learn than C; and this is after I already knew C. (At least - learn rust to the point of feeling productive, and like I wasn’t fighting the borrow checker constantly). Arguably becoming an expert in C means you need to understand all the nuances of undefined behaviour. And that’s a much harder process. But it can happen slowly. Rust preloads all the pain. You essentially can’t write rust at all until you understand rust references, lifetimes (implicit and explicit) and the borrowchecker. The payoff is huge, but I found climbing that mountain to be no joke.

adrianN 3y ago
Given the number of CVEs that can be directly attributed to C and C++ you only need to be half-joking to argue that approximately nobody has managed to learn the languages sufficiently to write production code in them.
- josephg 3y ago
  As uncomfortable as this is to say, the existence of latent security vulnerabilities doesn’t seem to stop people from shipping a lot of apparently working code in C and C++. And I don’t think a lot of those CVEs come from people misunderstanding the languages. As I understand it they mostly come from honest software bugs. C++ makes it easy for honest mistakes by experts to become security nightmares. This is a controversial opinion - but I think the fault is in C and C++ themselves. Not the programmers who need to work even harder such that they stop ever making mistakes.
  - vacuity 3y ago
    Which is why some people push for no longer using C and C++ as much as possible. It's just not feasible to expect the average programmer to avoid all the security pitfalls. Of course, whether Rust is the best option isn't a given.
    - josephg 3y ago
      There aren’t a lot of memory safe options if you want the kind of performance rust offers. Rust is fine, but it’s far from perfect. It’s hard to learn, complex, and the macro and async systems are honestly a bit of a mess. I’m really looking forward to whatever comes after rust. I’m hoping some bright sparks out there manage to make a language with rust’s memory safety but that cleans up some of rust’s rough edges.
      - tracker1 3y ago
        To be fair, how many applications really need Rust's level of performance? I mean operating system code and drivers... But, many apps are getting the job done in electron with a browser engine. I like rust, I like the sensibilities. Maybe my experience is too limited to higher level problems though. There's plenty of room for the likes of Go, Java and C# is all I'm getting at.
        josephg 3y ago
        Yeah I think I broadly agree with you. Not many applications need rust's performance. Go, Java, C#, nodejs, python, etc are all great languages. But the software which does need or want "native performance" is incredibly important software. I'd use rust for things like databases, operating systems, web browsers, high performance web servers, network services (samba, ssh), and other "systems" software like that. Most of the lines of code ever written are probably in application code. If you're making a company website, python or C# or whatever is totally fine. But a remarkable proportion of the lines of code your computer actually runs were written in C or C++. Your web server might be in python, but if you use nginx as a proxy - well, thats C++ (I think). Use postgres? C++. Running your software in linux? C. Testing with Chrome? C++. What is python itself written in? I dunno, but I bet its either C or C++. You get the picture. Whether or not rust is a big deal is largely a matter of focus.
- LtWorf 3y ago
  So you're saying there is no CVE in php, java, go, js, and python?
  - josephg 3y ago
    In their defence, there are entire classes of security bugs that memory safe languages protect you from. A large percentage of the security bugs in Chrome, OpenSSL, iMessage and lots of other apps wouldn’t have happened in any of the languages you listed. Or, almost certainly, in Rust.
    - Xeamek 3y ago
      And how many of such bugs could be prevented with compiler warnings and flags?
      - tracker1 3y ago
        If you're going to start writing it testing or C++ like Rust or follow certain guidelines, a lot of them. But if you're going to constrain how you do things, why not use a language that also gives you higher level functionality along the way?
        Xeamek 3y ago
        I agree. My point is that I just feel like "but someone please think of the ̶ ̶c̶h̶i̶l̶d̶r̶e̶n̶ memory safety" argument is over blown. There are ways to eliminate majority of those issues in cpp as well, but people simply don't care. If You want to use Rust because it's just better language - go for it, I do it as well. But let's actually use that as an argument, instead of hiding behind superficial ones
        josephg 3y ago
        > There are ways to eliminate majority of those issues in cpp as well, but people simply don't care. If its that easy, why do Google, Apple, Microsoft and basically everyone else keep making memory safety related bugs? Are they all just idiots? Do you think they just don't care about security? Carmack found C++ static analysis tools found mountains of latent bugs in the quake source code - despite the game running great. Personally I find it a very arrogant statement to claim that memory safety in C++ is easy. If google finds it hard, despite throwing millions each year into the problem, I'm of a mind to believe them.
zozbot234 3y ago
> You essentially can’t write rust at all until you understand rust references, lifetimes (implicit and explicit) and the borrowchecker. You can if you're willing to use stuff like .clone() and the interior mutability types. In Rust, you can tell when code has been written to be a bit sloppy because it has that kind of boilerplate. And the compiler checks are a huge help when it comes to refactoring the code and making it cleaner and better-performing.
- josephg 3y ago
  Eh. If you don’t know how references work in rust, you’ll struggle to use most of the standard library or any 3rd party crates. And if you can’t pass mutable references to functions or iterators there’s a lot of programs that will be hard to write at all. Performance will be pretty rubbish too. You might be able to write some simple programs, but I wouldn’t say you know rust yet, or could really be productive with the language.
riku_iki 3y ago
> I found rust significantly harder to learn than C language itself maybe, but you also need to learn ecosystem, libs, build systems, testing. Benchmark could be: how fast you can learn and bootstrap some type of app of your choice: high performance DB or torrent server, etc. > You essentially can’t write rust at all until you understand rust references, lifetimes (implicit and explicit) and the borrowchecker why is that? You can write rust the same way you write C but with nicer syntax, standard lib and build system and more potential to future expansion.
- josephg 3y ago
  > but you also need to learn ecosystem, libs, build systems, testing. That’s a really good point that I hadn’t thought of. If we include header files, compiling and linking, makefiles and CMake and the mess of dealing with 3rd party libraries in C - well, yeah. All that stuff is probably worse than learning the rust borrow checker. I think I’ve forgotten how horrific that mountain is for beginners because I learned most of it decades ago, while the pain of learning rust is still fresh. > why is that? You can write rust the same way you write C Because I use pointers everywhere in my C code. Rust’s borrow checker simply won’t compile my code if I transliterate it directly from C. There are software patterns which work well in rust with the borrow checker in mind - but they take time to learn and get used to. Until you do, you simply aren’t productive.
  - riku_iki 3y ago
    > Because I use pointers everywhere in my C code. Rust’s borrow checker simply won’t compile my code if I transliterate it directly from C. borrow checker is more relevant to C references I think. For pointers you can use Arc or Rc and don't worry about borrow checker. Disclaimer, I am not a rust or c coder, so my opinion has a high chance to be wrong..
    - josephg 3y ago
      If you want to learn rust, there really isn’t a way to avoid learning lifetimes and the borrow checker. It’s a core part of how the language works. You can probably get partway there with Rc and by cloning stuff everywhere but you’ll still run into borrowck problems. Rc doesn’t turn off the borrow checker. (Nor does unsafe). But then you won’t have the tools to solve your problems. And you also won’t know how to use most of the standard library or any crates. That’s no way to write rust. > Disclaimer, I am not a rust or c coder, so my opinion has a high chance to be wrong.. I’ll take a step back. I hope this is helpful to someone and not patronising. Go and similar languages are memory safe because no matter what go code you write, go runs your program with a GC that makes sure your variables are freed correctly only when it’s safe to do so. Rust’s safety is very different. It comes from checking at compile time that your program is written in a way that obeys a bunch of complex rules. For that to work, you have to write your code very carefully. If you mess up, the compiler doesn’t fix it for you. It just refuses to compile. So you have to write your code with those invariants in mind, or your program won’t build at all. C code generally doesn’t obey any of rust’s rules - for obvious reasons. If you were to just blithely translate C to rust code, the rust compiler will refuse to compile your program because the rules aren’t being followed. To write rust code that the compiler accepts, you need to first learn the borrow checker’s way of seeing the world. Then you need to restructure your code to work in accordance to rust’s rules. And sometimes that’s a super obscure and tricky problem. Weirdly, I think it’d be much easier to go the other way. Any compiling rust program could be translated into a memory safe C program if we had a compiler that did that. (I think). And lots of C programmers say learning rust made them better at C - because rust’s rules genuinely teach you to be more disciplined with memory and show you some clear rules for making C code that’s much less error prone. Not learning the borrow checker is like not learning how objects work in Python. You could write some simple programs. But you’re going to have a bad time, especially if you try to do anything nontrivial, use library code or read anyone else’s programs.

edgyquant 3y ago

Objectively false

pjmlp 3y ago

As someone that speaks legalese, and knows C and C++ relatively well to be productive, if nothing else by knowing them since 1993 and 1994 respectively, also have already written a couple of interesting stuff in Rust, that 100x easier is a bit too much. Specially if we are talking about anything related to graphics programming, or asynchronous programming.