4 ms·

If you are building high-performance, high-scale systems software (e.g. database engines), modern C++ is by far the preferred choice for new software projects a

If you are building high-performance, high-scale systems software (e.g. database engines), modern C++ is by far the preferred choice for new software projects and next generation systems. The notion of C++ being "useful mostly for legacy codebases" is not in evidence. The reality, for better or worse, is that there is no satisfactory replacement currently for C++ for important classes of software even if starting from a completely blank slate. I like some of those other languages, they just can't do the job in a reasonable way. The reason modern C++ is still the preferred language for some types of software is that it is significantly more expressive in critical ways, which has a substantial impact on software robustness, maintainability, and performance. You could use those other languages, but it would produce a substantially worse product and/or codebase. To put it another way, there is often no way to translate an existing elegant modern C++ codebase into those other languages without major compromises to either the codebase or performance. And for the kinds of applications where C++ is preferred, those compromises are largely unacceptable. Maybe some of those other languages will approach the practical expressiveness of modern C++ for this kind of software eventually, but not anytime in the near future.

mbrodersen 5y ago
There are literally millions of C++ developers out there. And that number is growing. There are new C++ projects started every single day. It will take a very long time for any other language to compete with C++. I agree that most biz software that doesn’t require high performance should be written in something else. But there are many application areas where C++ still completely dominates. Look at commercial games for example, browsers, JIT compilers etc. Yes Rust might be able to do a good job in those domains but it is hard to compare with the C++ momentum.
seeekr 5y ago
I would be very interested in hearing a few concrete examples!
pcwalton 5y ago
This is not true. Nor is the post you're replying to, for what it's worth. Rust and C++ are roughly equally expressive for high-performance, high-scale software. The reasons to use one or the other for new code have little to do with whether each language can do the job; clearly, both languages can. Rather, what dominates are factors like whether your build/deployment system is set up to handle one language or another, what your engineers are experienced in, whether you care about memory safety, etc. Source: I'm one of the maintainers of Rust at a large organization you have heard of that very much cares about high-performance, high-scale systems software.
- zozbot234 5y ago
  > clearly, both languages can. C++ is not memory safe, which is table stakes these days for any truly "high scale" software. Which is why most large-scale software projects have been written in Java, a memory-safe language, since the late 1990s (taking over from the previously common use of C++). And no, even the C++ Core Guidelines and "modern" coding style do not fully address this issue; they're way too clunky, whether or not legacy code is involved. Rust, even more so than Java in the mid-1990s, is uniquely positioned in offering better performance and safety than C++ and a lower complexity in development.
  - pjmlp 5y ago
    All big GPU and HPC related companies have ISO C++ people on their payroll, so I doubt they will care to add something else. And NVidia rather uses Ada/SPARK instead of Rust for high integrity computing. In regards to Java, while I do agree, there is still enough JNI being used there, hence why Project Panama, to improve such workflows where C++ is part of the story.
- worik 5y ago
  True. But. The learning curve of Rust should not be underestimated, IMHO. I do not know except by my own experience and "gossip", and would be interested in hearing from a bigger shop that has to deal with it. Rust can make an experienced developer feel utterly clueless. The borrow checker is a very harsh mistress. Moving from C++ to Rust for a computer programmer with many years of experience in C++ must be a frustrating and humbling experience. The simplest things become so hard. I love Rust, but I do not use it professionally (I would love to). I can clearly see that it is a step closer to what we have been waiting for, it may even be the destination. But I can imagine the pain of moving a programmer from 20 years of C++ into Rust. Becoming a novice again
  - zozbot234 5y ago
    > The learning curve of Rust should not be underestimated, IMHO. Not sure how this is relevant in a conversation about C++, for which the notion of a learning curve is even hard to apply given that practically no one manages to write code that can be trusted to be free of basic defects in the language. > Rust can make an experienced developer feel utterly clueless. The borrow checker is a very harsh mistress. And rightly so. Rust is only unique in that you get the hangover before deploying the code in production. It's puzzling that some might see this as a drawback of the language.
AshamedCaptain 5y ago
Not to mention that to embark right now on a fancy-language-of-the-week codebase could be a career ending (and/or even company ending) mistake. I mean, I still work regularly on C++ codebases that are >30 years old (no STL!) and are supported and extended and even switch companies from time to time. God knows how many "languages of the future" we've had in these 30 years.

mbrodersen 5y ago

There are literally millions of C++ developers out there. And that number is growing. There are new C++ projects started every single day. It will take a very long time for any other language to compete with C++. I agree that most biz software that doesn’t require high performance should be written in something else. But there are many application areas where C++ still completely dominates. Look at commercial games for example, browsers, JIT compilers etc. Yes Rust might be able to do a good job in those domains but it is hard to compare with the C++ momentum.

seeekr 5y ago

I would be very interested in hearing a few concrete examples!

pcwalton 5y ago

This is not true. Nor is the post you're replying to, for what it's worth. Rust and C++ are roughly equally expressive for high-performance, high-scale software. The reasons to use one or the other for new code have little to do with whether each language can do the job; clearly, both languages can. Rather, what dominates are factors like whether your build/deployment system is set up to handle one language or another, what your engineers are experienced in, whether you care about memory safety, etc. Source: I'm one of the maintainers of Rust at a large organization you have heard of that very much cares about high-performance, high-scale systems software.

zozbot234 5y ago
> clearly, both languages can. C++ is not memory safe, which is table stakes these days for any truly "high scale" software. Which is why most large-scale software projects have been written in Java, a memory-safe language, since the late 1990s (taking over from the previously common use of C++). And no, even the C++ Core Guidelines and "modern" coding style do not fully address this issue; they're way too clunky, whether or not legacy code is involved. Rust, even more so than Java in the mid-1990s, is uniquely positioned in offering better performance and safety than C++ and a lower complexity in development.
- pjmlp 5y ago
  All big GPU and HPC related companies have ISO C++ people on their payroll, so I doubt they will care to add something else. And NVidia rather uses Ada/SPARK instead of Rust for high integrity computing. In regards to Java, while I do agree, there is still enough JNI being used there, hence why Project Panama, to improve such workflows where C++ is part of the story.
worik 5y ago
True. But. The learning curve of Rust should not be underestimated, IMHO. I do not know except by my own experience and "gossip", and would be interested in hearing from a bigger shop that has to deal with it. Rust can make an experienced developer feel utterly clueless. The borrow checker is a very harsh mistress. Moving from C++ to Rust for a computer programmer with many years of experience in C++ must be a frustrating and humbling experience. The simplest things become so hard. I love Rust, but I do not use it professionally (I would love to). I can clearly see that it is a step closer to what we have been waiting for, it may even be the destination. But I can imagine the pain of moving a programmer from 20 years of C++ into Rust. Becoming a novice again
- zozbot234 5y ago
  > The learning curve of Rust should not be underestimated, IMHO. Not sure how this is relevant in a conversation about C++, for which the notion of a learning curve is even hard to apply given that practically no one manages to write code that can be trusted to be free of basic defects in the language. > Rust can make an experienced developer feel utterly clueless. The borrow checker is a very harsh mistress. And rightly so. Rust is only unique in that you get the hangover before deploying the code in production. It's puzzling that some might see this as a drawback of the language.

AshamedCaptain 5y ago

Not to mention that to embark right now on a fancy-language-of-the-week codebase could be a career ending (and/or even company ending) mistake. I mean, I still work regularly on C++ codebases that are >30 years old (no STL!) and are supported and extended and even switch companies from time to time. God knows how many "languages of the future" we've had in these 30 years.