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C++ almost never removes features because of the ABI compatibility guarantees. Programs compiled with older versions of the standard can be linked against newer

by jjmarr 7mo ago

C++ almost never removes features because of the ABI compatibility guarantees. Programs compiled with older versions of the standard can be linked against newer versions. This is allegedly because in the 80s companies would write software, fire the programmers, and throw the source code away once it compiled.

Sharlin 7mo ago
Fixing syntax by definition does not affect the ABI. And Rust has shown that both ABI and API compatibility can be achieved in the presence of several "versions" (editions) of the language in the same build.
- irishcoffee 7mo ago
  Rust has shown that it’s yet another language that kind of sort of addresses 3% of the issues c/c++ has, tops.
  - tialaramex 7mo ago
    I really don't like C++ but it's hard to come up with thirty-odd times as many other terrible problems as the ones Rust addresses.
  - saghm 7mo ago
    Probably because like 95% of C++'s issues are self-inflicted and don't need to be addressed if you use a different language in the first place, and 1% of them are fundamentally unsolvable by any language.
  - vlovich123 7mo ago
    lol. A functions module system that’s easy to use and adopted? A package manager? A well implemented hash table? Fast compile times? Effectively no segfaults? Effectively no memory leaks? Comparatively no race condition bugs? A benchmark and unit test framework baked into the language? Auto optimization of the layout of structs? No UB? I don’t know what you’re counting as “3% of the issues” but if those are the 3%, they sound like massive productivity and safety wins that’s not existed in a language with a similar performance profile to C/C++.
    - jjmarr 7mo ago
      Is Rust faster to compile than C++?
      - tialaramex 7mo ago
        Different (though related) things make compiling Rust slow. In both cases the compiler can spend a lot of time working on types which you, as programmer, weren't really thinking about. Rust cares about types which could exist based on what you wrote but which you never made, whereas C++ doesn't care about that, but it does need to do a lot of "from scratch" work for parametrised types that Rust doesn't have to because C++ basically does a lot of textual substitution in template expansion rather than "really" having parametrised typing. If you're comparing Clang the backend optimiser work is identical in both cases it's LLVM. People who've never measured often believe Rust's borrowck needs a lot of compiler effort but actual measurements don't agree - it's not free but it's very cheap (in terms of proportion of compiler runtime).
        vlovich123 7mo ago
        For most day to day cases, rust will actually compile faster because the build system will do good incremental builds - not perfect, but better than c++. Also clean builds are still “perfectly” parallelized by default. And yes, while rust has a reputation for being slow, in my experience it’s faster for most projects you encounter in practice because the c++ ecosystem is generally not parallelized and even if it is many projects have poor header hygiene that makes things slow.
  - Sharlin 7mo ago
    Do you actually know Rust or were you just talking out if hour ass? I’d like you to enumerate even thirty problems of C or C++ that Rust doesn’t fix, never mind hundreds (because Rust fixes a metric shit ton of C/C++ problems!)

by jjmarr 7mo ago

Sharlin 7mo ago

Fixing syntax by definition does not affect the ABI. And Rust has shown that both ABI and API compatibility can be achieved in the presence of several "versions" (editions) of the language in the same build.

irishcoffee 7mo ago
Rust has shown that it’s yet another language that kind of sort of addresses 3% of the issues c/c++ has, tops.
- tialaramex 7mo ago
  I really don't like C++ but it's hard to come up with thirty-odd times as many other terrible problems as the ones Rust addresses.
- saghm 7mo ago
  Probably because like 95% of C++'s issues are self-inflicted and don't need to be addressed if you use a different language in the first place, and 1% of them are fundamentally unsolvable by any language.
- vlovich123 7mo ago
  lol. A functions module system that’s easy to use and adopted? A package manager? A well implemented hash table? Fast compile times? Effectively no segfaults? Effectively no memory leaks? Comparatively no race condition bugs? A benchmark and unit test framework baked into the language? Auto optimization of the layout of structs? No UB? I don’t know what you’re counting as “3% of the issues” but if those are the 3%, they sound like massive productivity and safety wins that’s not existed in a language with a similar performance profile to C/C++.
  - jjmarr 7mo ago
    Is Rust faster to compile than C++?
    - tialaramex 7mo ago
      Different (though related) things make compiling Rust slow. In both cases the compiler can spend a lot of time working on types which you, as programmer, weren't really thinking about. Rust cares about types which could exist based on what you wrote but which you never made, whereas C++ doesn't care about that, but it does need to do a lot of "from scratch" work for parametrised types that Rust doesn't have to because C++ basically does a lot of textual substitution in template expansion rather than "really" having parametrised typing. If you're comparing Clang the backend optimiser work is identical in both cases it's LLVM. People who've never measured often believe Rust's borrowck needs a lot of compiler effort but actual measurements don't agree - it's not free but it's very cheap (in terms of proportion of compiler runtime).
      - vlovich123 7mo ago
        For most day to day cases, rust will actually compile faster because the build system will do good incremental builds - not perfect, but better than c++. Also clean builds are still “perfectly” parallelized by default. And yes, while rust has a reputation for being slow, in my experience it’s faster for most projects you encounter in practice because the c++ ecosystem is generally not parallelized and even if it is many projects have poor header hygiene that makes things slow.
- Sharlin 7mo ago
  Do you actually know Rust or were you just talking out if hour ass? I’d like you to enumerate even thirty problems of C or C++ that Rust doesn’t fix, never mind hundreds (because Rust fixes a metric shit ton of C/C++ problems!)