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> There are reasonably good c++11 conventions for lifetimes [...] Almost nobody follows them [...] I swear I'm not trying to be snarky or rude here, but is it

> There are reasonably good c++11 conventions for lifetimes [...] Almost nobody follows them [...] I swear I'm not trying to be snarky or rude here, but is it actually a "convention" if almost nobody follows it? This seems like one example of my general issue with C++, in that it could be great if everyone agreed to a restricted subset, but of course nobody can coordinate such agreement and it doesn't exist outside companies large and important enough to enforce their own in-house C++ standards (e.g. Google).

spookie 2y ago
Honestly, I blame MSVC for a lot of lost momentum when adopting new standards, given it takes them more than 4 years implementing those features. Ofc, this isn't the case for C++11 today, but a lot of projects were started prior to 2015. And don't get me started on C itself. Jesus Christ.
- pjmlp 2y ago
  They certainly aren't to blame for the state of C and C++ adoption on UNIX, Sony and Nintendo, and embedded. They are the only C++ compiler that properly supports all C++20 modules use cases, while clang still doesn't do Parallel STL from C++17, for example. They support C17 nowadays, where many embedded folks are slowly adopting C99. And the UNIX story outside clang and GCC is quite lame, most still stuck in C++14, catching up to C++17. Likewise, consoles, C++17.
  - spookie 2y ago
    I wouldn't say they "support" C17. Perhaps with a big asterisk. Even with C11, they implemented _parts_ of the standard, but didn't ship some of its libs (threads come to mind). Same deal in C17. Any hopes of porting over standard compliant C code to MSVC are met with lots of additional porting work. Also, if we do move the discussion outside GCC and Clang, then I don't know what to say man. Why not use GCC or Clang? Are there many UNIX out there not having either? Seems unlikely.
bluGill 2y ago
What we have is a human problem. The convention exists in enough places (though in slightly different forms) to call it a convention, but it needs more adoption. Every once in a while someone who writes a lot of Rust will blog about some code they discovered that was 'unsafe' and after looking close they realized it wasn't doing something that fundamentally required unsafe (and often fixing the code to be safe fixed real bugs). C++ and Rust have to leave people enough rope to hang themselves in order to solve the problems they want to solve, but that means people will find a way to do stupid things.
- orf 2y ago
  What arguments like this fail to understand is that conventions without guardrails, culture and/or guarantees are next to useless. That’s not a human problem. It’s like saying “this motorway is pitch black, frequently wet and slippery and has no safety barriers between sides, so crashes are frequent and fatal. What we have is a human problem - drivers should follow the convention of driving at 10mph, when it doesn’t rain and make sure they are on the right side of the road at all times”.
  - bluGill 2y ago
    Which is what this whole story is about: how can we add those things to C++? There are lots of options, which should we try. Which sound good but won't work (either technically or because they are not adopted), vs which will.
    - orf 2y ago
      The whole story is about how you cant do this without lifetime annotations. In other words: you can try limiting all cars to 10mph, closing the road, automatically switching out all car tyres with skid-proof versions while in motion, or anything else. But… just turn the god damn lights on and put up a barrier between lanes. It works on every other road.
- pjmlp 2y ago
  Despite all the security improvements that Microsoft has pushed for, here is one of the latest posts on Old New Thing. https://devblogs.microsoft.com/oldnewthing/20241023-00/?p=110411 https://devblogs.microsoft.com/oldnewthing/20241023-00/?p=11... Notice the use of C's memcpy() function. This is exactly the kind of posts where showing best practises would be quite helpful, as education.

spookie 2y ago

Honestly, I blame MSVC for a lot of lost momentum when adopting new standards, given it takes them more than 4 years implementing those features. Ofc, this isn't the case for C++11 today, but a lot of projects were started prior to 2015. And don't get me started on C itself. Jesus Christ.

pjmlp 2y ago
They certainly aren't to blame for the state of C and C++ adoption on UNIX, Sony and Nintendo, and embedded. They are the only C++ compiler that properly supports all C++20 modules use cases, while clang still doesn't do Parallel STL from C++17, for example. They support C17 nowadays, where many embedded folks are slowly adopting C99. And the UNIX story outside clang and GCC is quite lame, most still stuck in C++14, catching up to C++17. Likewise, consoles, C++17.
- spookie 2y ago
  I wouldn't say they "support" C17. Perhaps with a big asterisk. Even with C11, they implemented _parts_ of the standard, but didn't ship some of its libs (threads come to mind). Same deal in C17. Any hopes of porting over standard compliant C code to MSVC are met with lots of additional porting work. Also, if we do move the discussion outside GCC and Clang, then I don't know what to say man. Why not use GCC or Clang? Are there many UNIX out there not having either? Seems unlikely.

bluGill 2y ago

What we have is a human problem. The convention exists in enough places (though in slightly different forms) to call it a convention, but it needs more adoption. Every once in a while someone who writes a lot of Rust will blog about some code they discovered that was 'unsafe' and after looking close they realized it wasn't doing something that fundamentally required unsafe (and often fixing the code to be safe fixed real bugs). C++ and Rust have to leave people enough rope to hang themselves in order to solve the problems they want to solve, but that means people will find a way to do stupid things.

orf 2y ago
What arguments like this fail to understand is that conventions without guardrails, culture and/or guarantees are next to useless. That’s not a human problem. It’s like saying “this motorway is pitch black, frequently wet and slippery and has no safety barriers between sides, so crashes are frequent and fatal. What we have is a human problem - drivers should follow the convention of driving at 10mph, when it doesn’t rain and make sure they are on the right side of the road at all times”.
- bluGill 2y ago
  Which is what this whole story is about: how can we add those things to C++? There are lots of options, which should we try. Which sound good but won't work (either technically or because they are not adopted), vs which will.
  - orf 2y ago
    The whole story is about how you cant do this without lifetime annotations. In other words: you can try limiting all cars to 10mph, closing the road, automatically switching out all car tyres with skid-proof versions while in motion, or anything else. But… just turn the god damn lights on and put up a barrier between lanes. It works on every other road.
pjmlp 2y ago
Despite all the security improvements that Microsoft has pushed for, here is one of the latest posts on Old New Thing. https://devblogs.microsoft.com/oldnewthing/20241023-00/?p=110411 https://devblogs.microsoft.com/oldnewthing/20241023-00/?p=11... Notice the use of C's memcpy() function. This is exactly the kind of posts where showing best practises would be quite helpful, as education.