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> Embracing Resource Acquisition Is Initialization (RAII) makes C++ the safest, most productive and fun C++ has ever been. This seems like an extremely low bar

> Embracing Resource Acquisition Is Initialization (RAII) makes C++ the safest, most productive and fun C++ has ever been. This seems like an extremely low bar. Anyway, what use is there for C++ in 2025 aside from maintenance of legacy codebases and game engines? Off-hand I'd say C++ programmers are twice as expensive as rust programmers for the same semantics, and then you're still stuck with a C++ programmer you need to figure out how to socialize with.

motorest 1y ago
> This seems like an extremely low bar. Is it, though? Most mainstream languages fail to support anything resembling RAII, at least as first-class support. Do you actually have an example of a language that does a better job at resource management than C++?
- asyx 1y ago
  Rust simply because the constructor being a static method on the type that can return basically anything including optional and result types and copy / move semantics are handled very easily through macros instead of constructor / assignment operator overrides.
  - deleted 1y ago
    [deleted]
  - motorest 1y ago
    > Rust simply because the constructor being a static method (...) This assertion makes no sense. RAII is not defined by whether you use factory functions or special member functions to initialize an object. In fact, RAII is only incidentally related ro memory management. RAII is a strategy to manage any and all types of resources, ranging from memory management to even files and TCP connections, by leveraging assurances that the runtime provides regarding scopes and object life cycles. None of this changes if you employ factory functions to initialize resources.
- palata 1y ago
  Not that I agree with the condescending parent (e.g. "you're still stuck with a C++ programmer you need to figure out how to socialize with"), but... > Most mainstream languages fail to support anything resembling RAII Wikipedia says: "RAII is associated most prominently with C++, where it originated, but also Ada,[3] Vala,[4] and Rust" > Do you actually have an example of a language that does a better job at resource management than C++? They don't necessarily offer a pattern like RAII, but what about "try-with-resources" in Java, or "use" in Kotlin that goes with `AutoCloseable`? And what about "using" in C#? What about "defer" in Swift? I find those simpler than RAII.
  - pjmlp 1y ago
    One caveat though, you need to pair those with static analysis tooling, if you want to ensure developers don't forget to make use of them.
    - palata 1y ago
      How does RAII solve that? Developers can "forget" to use RAII, right? Or are you saying that it's easier to spot because RAII requires quite a bunch of boilerplate (whereas a one-liner like "defer" is easier to forget)? Not criticising, really trying to understand :-).
      - pjmlp 1y ago
        RAII when supported natively by the language, is done at the implementation level, not the usage point. So in languages like Rust, D, Ada, Swift, C++, the compiler will do the rest unless you go out of your way to avoid the call to take place, like placing a value type on the heap using plain pointers. With the other approach, even if you implement IDisposable, AutoCloseable, ContextManager and similar, you have to remember to manually write the code pattern that takes care of calling close(), or whatever the method/function happens to be called. In languages with good support for FP patterns, like trailing lambdas, currying and such, there is another pattern, that is much safer, in case you don't want a static analysis tool to track resource usage, the with pattern. You do something like withDBConnection connection (fun db -> all related db operations). Assuming the lambda doesn't do naughty things to have db parameter escape the scope, the withDBConnection function will take care of handling the whole connection lifecycle.
- tialaramex 1y ago
  Obviously a language with linear types is just better at this, such as Austral. In terms of languages you'd actually deploy today Rust is better both at this narrow feature and more broadly.
- znkr 1y ago
  When I switched from C++ to a bunch of other languages, I missed RAII initially. However, I quickly learned that other languages just do it differently and often even better (ever had to check an error when closing a resource?). Nowadays, I think that RAII is a solution to a C++ problem and other languages have a better solution for resource management (try-with-resources in Java, defer in Go, with in Python).
  - motorest 1y ago
    > However, I quickly learned that other languages just do it differently and often even better (ever had to check an error when closing a resource?). I don't think that's even conceptually the same. The point of RAII is that resource deallocation is ensured, deterministic, and built into the happy path. Once you start to throw errors and relying on those to manage resources, you're actually dealing the consequences of not having RAII.
  - oytis 1y ago
    > try-with-resources in Java, defer in Go, with in Python Or 'goto error8;' in C. Still RAII is much more convenient, especially for cases where you allocate a lot of interdependent resources at different time points. It keeps deallocation logic close to allocation logic (unlike, say, defer), makes sure deallocation always happens in the reverse order of allocations and doesn't force you to create a nested scope each time you allocate a resource
- pjmlp 1y ago
  Ada/SPARK, with better ergonomics than Rust, but its use will stay niche in high integrity computing.
pjmlp 1y ago
For one, the compiler and runtime implementation of the language you might happen to use, that that includes Rust.
oytis 1y ago
Where are C++ programmers paid better than Rust programmers? I thought Rust salaries are being driven high by all the crypto/fintech companies + scarcity
- bluGill 1y ago
  productivity counts not hours. If you can get the same work done faster then you cost to the company is lower even - possible even if your salery is higher. though it isn't clear how much of rust's increased productivity is caused by being a new language where the architecture mistakes of the past decades are not slowing you down. We will need several more decades to answer that.
flohofwoe 1y ago
> stuck with a C++ programmer you need to figure out how to socialize with. You're obviously trolling, but: IME Rust attracts the same 'difficult' characters that are also attracted to C++ (because both are 'puzzle solving languages' instead of 'problem solving languages') the typical Rust coder may be even worse because of the missionary fervor and 'holier than thou' attitude.
- oytis 1y ago
  Puzzle-solving languages are rather Lisp or Haskell. Both C++ and Rust are very practical for their problem domain.
  - djmips 1y ago
    Oh no, C++ has template meta programming and the ability to mask a DSL as advanced architecture, and then you can even implement Lisp or pick your favorite while claiming you're coding in C...++
  - sesm 1y ago
    IDK about Haskell, but iterating in REPL with Lisp is the most practical form of programming I've experienced. In other mainstream practical languages this approach is reintroduced as a productivity tool like Quokka, etc. C++ was practical some decades ago (hardware-friendly variant of OOP for GUI), but it failed as a library language and the domain where it's practical on modern hardware is much smaller. I will not say anything about Rust.
    - delta_p_delta_x 1y ago
      > but it failed as a library language This is very inaccurate. Essentially every high-performance library, user-mode driver, desktop application, and more is written in nothing but C++. Give me any library you can think of, and I assure you it is written in C++ (or maybe C, but this is masochism on the part of the developers). Even libraries for other languages like numpy, pandas, pytorch, etc are written in C++.
BoingBoomTschak 1y ago
Once Qt is properly accessible in Rust, I think your claim will be a lot more realistic. This goes for other important C/C++ libraries (e.g. libavcodec, vips/ImageMagick, VTK) without a solid (maintained, documented, etc...) Rust interface.
- tialaramex 1y ago
  Qt is a C++ kitchen sink library - perhaps it feels very important to C++ programmers but I can't imagine Rust people are looking forward to having more redundant types that do exactly the same thing as a type they've used for years but like, now with a Q in their name. The fact that lists like yours so often end up being "Look at all these C libraries" ie not actually about C++ at all is revealing. It's an endorsement of Bjarne's position that he needed that C compatibility, decades later C++ alternatives remain unpopular but it also tells you that you're never going to raise the bar this way. C++ is not a route out. AFAIK there is no equivalent of rustls-openssl-compat for C++. The knowledge that this library (OpenSSL) is trash never spurred any C++ programmers to do better and provide the same ABI but with a C++ implementation.
  - BoingBoomTschak 1y ago
    What's your point? There's a lot to criticize about these libraries, but the fact remains that they're considered important and basically impossible to rewrite from scratch. Of course, Rust could get a rock solid portable GUI toolkit that doesn't rely on a webview (probably not much harder than wrapping Qt, to be honest), but it's not there yet. I'm not in love with them or the abomination known as C++, if that's what you're implying.
    - tialaramex 1y ago
      > basically impossible to rewrite from scratch How so? This definitely needs at least a citation of somebody who can explain in detail why this code is "impossible to rewrite". Who wrote the one we have now, Martians?
    - ogoffart 1y ago
green7ea 1y ago
Author here, I do prefer a language like Rust that makes all of this automatic but that isn't always an option. There are other parts of Rust that can be hard as well. I wrote this article for a few friends who have recently started working with an existing, large C++ code base. Some industries like the video game industry have also stuck to C++ (they have their reasons). A good programmer can work within the given constraints to make a useful program — sometimes, one of those constraints is the choice of language.

motorest 1y ago

> This seems like an extremely low bar. Is it, though? Most mainstream languages fail to support anything resembling RAII, at least as first-class support. Do you actually have an example of a language that does a better job at resource management than C++?

asyx 1y ago
Rust simply because the constructor being a static method on the type that can return basically anything including optional and result types and copy / move semantics are handled very easily through macros instead of constructor / assignment operator overrides.
- deleted 1y ago
  [deleted]
- motorest 1y ago
  > Rust simply because the constructor being a static method (...) This assertion makes no sense. RAII is not defined by whether you use factory functions or special member functions to initialize an object. In fact, RAII is only incidentally related ro memory management. RAII is a strategy to manage any and all types of resources, ranging from memory management to even files and TCP connections, by leveraging assurances that the runtime provides regarding scopes and object life cycles. None of this changes if you employ factory functions to initialize resources.
palata 1y ago
Not that I agree with the condescending parent (e.g. "you're still stuck with a C++ programmer you need to figure out how to socialize with"), but... > Most mainstream languages fail to support anything resembling RAII Wikipedia says: "RAII is associated most prominently with C++, where it originated, but also Ada,[3] Vala,[4] and Rust" > Do you actually have an example of a language that does a better job at resource management than C++? They don't necessarily offer a pattern like RAII, but what about "try-with-resources" in Java, or "use" in Kotlin that goes with `AutoCloseable`? And what about "using" in C#? What about "defer" in Swift? I find those simpler than RAII.
- pjmlp 1y ago
  One caveat though, you need to pair those with static analysis tooling, if you want to ensure developers don't forget to make use of them.
  - palata 1y ago
    How does RAII solve that? Developers can "forget" to use RAII, right? Or are you saying that it's easier to spot because RAII requires quite a bunch of boilerplate (whereas a one-liner like "defer" is easier to forget)? Not criticising, really trying to understand :-).
    - pjmlp 1y ago
      RAII when supported natively by the language, is done at the implementation level, not the usage point. So in languages like Rust, D, Ada, Swift, C++, the compiler will do the rest unless you go out of your way to avoid the call to take place, like placing a value type on the heap using plain pointers. With the other approach, even if you implement IDisposable, AutoCloseable, ContextManager and similar, you have to remember to manually write the code pattern that takes care of calling close(), or whatever the method/function happens to be called. In languages with good support for FP patterns, like trailing lambdas, currying and such, there is another pattern, that is much safer, in case you don't want a static analysis tool to track resource usage, the with pattern. You do something like withDBConnection connection (fun db -> all related db operations). Assuming the lambda doesn't do naughty things to have db parameter escape the scope, the withDBConnection function will take care of handling the whole connection lifecycle.
tialaramex 1y ago
Obviously a language with linear types is just better at this, such as Austral. In terms of languages you'd actually deploy today Rust is better both at this narrow feature and more broadly.
znkr 1y ago
When I switched from C++ to a bunch of other languages, I missed RAII initially. However, I quickly learned that other languages just do it differently and often even better (ever had to check an error when closing a resource?). Nowadays, I think that RAII is a solution to a C++ problem and other languages have a better solution for resource management (try-with-resources in Java, defer in Go, with in Python).
- motorest 1y ago
  > However, I quickly learned that other languages just do it differently and often even better (ever had to check an error when closing a resource?). I don't think that's even conceptually the same. The point of RAII is that resource deallocation is ensured, deterministic, and built into the happy path. Once you start to throw errors and relying on those to manage resources, you're actually dealing the consequences of not having RAII.
- oytis 1y ago
  > try-with-resources in Java, defer in Go, with in Python Or 'goto error8;' in C. Still RAII is much more convenient, especially for cases where you allocate a lot of interdependent resources at different time points. It keeps deallocation logic close to allocation logic (unlike, say, defer), makes sure deallocation always happens in the reverse order of allocations and doesn't force you to create a nested scope each time you allocate a resource
pjmlp 1y ago
Ada/SPARK, with better ergonomics than Rust, but its use will stay niche in high integrity computing.

pjmlp 1y ago

For one, the compiler and runtime implementation of the language you might happen to use, that that includes Rust.

oytis 1y ago

Where are C++ programmers paid better than Rust programmers? I thought Rust salaries are being driven high by all the crypto/fintech companies + scarcity

bluGill 1y ago
productivity counts not hours. If you can get the same work done faster then you cost to the company is lower even - possible even if your salery is higher. though it isn't clear how much of rust's increased productivity is caused by being a new language where the architecture mistakes of the past decades are not slowing you down. We will need several more decades to answer that.

flohofwoe 1y ago

> stuck with a C++ programmer you need to figure out how to socialize with. You're obviously trolling, but: IME Rust attracts the same 'difficult' characters that are also attracted to C++ (because both are 'puzzle solving languages' instead of 'problem solving languages') the typical Rust coder may be even worse because of the missionary fervor and 'holier than thou' attitude.

oytis 1y ago
Puzzle-solving languages are rather Lisp or Haskell. Both C++ and Rust are very practical for their problem domain.
- djmips 1y ago
  Oh no, C++ has template meta programming and the ability to mask a DSL as advanced architecture, and then you can even implement Lisp or pick your favorite while claiming you're coding in C...++
- sesm 1y ago
  IDK about Haskell, but iterating in REPL with Lisp is the most practical form of programming I've experienced. In other mainstream practical languages this approach is reintroduced as a productivity tool like Quokka, etc. C++ was practical some decades ago (hardware-friendly variant of OOP for GUI), but it failed as a library language and the domain where it's practical on modern hardware is much smaller. I will not say anything about Rust.
  - delta_p_delta_x 1y ago
    > but it failed as a library language This is very inaccurate. Essentially every high-performance library, user-mode driver, desktop application, and more is written in nothing but C++. Give me any library you can think of, and I assure you it is written in C++ (or maybe C, but this is masochism on the part of the developers). Even libraries for other languages like numpy, pandas, pytorch, etc are written in C++.

BoingBoomTschak 1y ago

Once Qt is properly accessible in Rust, I think your claim will be a lot more realistic. This goes for other important C/C++ libraries (e.g. libavcodec, vips/ImageMagick, VTK) without a solid (maintained, documented, etc...) Rust interface.

tialaramex 1y ago
Qt is a C++ kitchen sink library - perhaps it feels very important to C++ programmers but I can't imagine Rust people are looking forward to having more redundant types that do exactly the same thing as a type they've used for years but like, now with a Q in their name. The fact that lists like yours so often end up being "Look at all these C libraries" ie not actually about C++ at all is revealing. It's an endorsement of Bjarne's position that he needed that C compatibility, decades later C++ alternatives remain unpopular but it also tells you that you're never going to raise the bar this way. C++ is not a route out. AFAIK there is no equivalent of rustls-openssl-compat for C++. The knowledge that this library (OpenSSL) is trash never spurred any C++ programmers to do better and provide the same ABI but with a C++ implementation.
- BoingBoomTschak 1y ago
  What's your point? There's a lot to criticize about these libraries, but the fact remains that they're considered important and basically impossible to rewrite from scratch. Of course, Rust could get a rock solid portable GUI toolkit that doesn't rely on a webview (probably not much harder than wrapping Qt, to be honest), but it's not there yet. I'm not in love with them or the abomination known as C++, if that's what you're implying.
  - tialaramex 1y ago
    > basically impossible to rewrite from scratch How so? This definitely needs at least a citation of somebody who can explain in detail why this code is "impossible to rewrite". Who wrote the one we have now, Martians?
  - ogoffart 1y ago

green7ea 1y ago

Author here, I do prefer a language like Rust that makes all of this automatic but that isn't always an option. There are other parts of Rust that can be hard as well. I wrote this article for a few friends who have recently started working with an existing, large C++ code base. Some industries like the video game industry have also stuck to C++ (they have their reasons). A good programmer can work within the given constraints to make a useful program — sometimes, one of those constraints is the choice of language.