4 ms·

In many application code bases no doubt. But how do you think make_unique and make_shared are implemented?

by RossBencina 2mo ago

pjmlp 2mo ago
With what will most likely become [[unsafe]] profile in C++29, assuming WG21 actually gets their profiles story right.
- bluGill 2mo ago
  I don't think adding unsafe will be possible - it will break too much existing code. We might be able to add something new that is only possible in an unsafe context, but there is too much existing code. However I do expect a [[safe]] profile (or perhaps several, depending on which paper you read) that everyone is encourage to opt-in to. Likely combines with compiler warnings and static analysis to encourage that use. (Also syntax is still open for debate)
  - pjmlp 2mo ago
    Check the WG21 mailing proposals. I was for Safe C++ paper, based on Circle experience, but it was shot down due to politics. So we're left with the profiles camp actually delivering, followed by the remaining compilers caring to actually implement them, otherwise it will be static and dynamic analysis as usual.
    - will4274 2mo ago
      It wasn't shot down due to politics. It was shot down because it solved the wrong problem.
      - pjmlp 2mo ago
        Yeah, that is why there was a paper created specifically to kill any other proposal, by the profiles folks with WG21 majority, and ironically profiles are just as annotation heavy, but since it is profiles, it is alright. I call that politics, and in the end the most likely outcome is that by C++29 nothing will be delivered by the profiles group, that is any better than using clang-tidy already today.
- saghm 2mo ago
  Classic C++, any issue is at most three years away from going away! There will definitely not be any other issues that are also three years from getting fixed when you reach that year though
  - pjmlp 2mo ago
    Actually no, because you are missing the time between standard being ratified and actuality being widely available in all major compilers. By the way, it is also classical Web standards, C, Vulkan, OpenCL, and everything else that has a similar process. Ideally we should have gotten rid of C and C++, but I haven't yet found a better Typescript for C.
    - saghm 2mo ago
      Fair enough, three years might be more of an upper bound than a lower bound. And yeah, the issue of having to wait is common to standard-based processes, but I've never seen anything else based on a standard so frequently have people need to jump in and try to dissuade people that issues matter because of the rolling timeline so frequently, regularly, and for such a long time as C++. Obviously it would be unreasonable to expect it to become perfect and not need any more changes, but like, I was hearing people complain about various aspects of `unique_ptr` a decade ago, and it seems like we're not even past that yet.

In many application code bases no doubt. But how do you think make_unique and make_shared are implemented?

pjmlp 2mo ago

With what will most likely become [[unsafe]] profile in C++29, assuming WG21 actually gets their profiles story right.

bluGill 2mo ago
I don't think adding unsafe will be possible - it will break too much existing code. We might be able to add something new that is only possible in an unsafe context, but there is too much existing code. However I do expect a [[safe]] profile (or perhaps several, depending on which paper you read) that everyone is encourage to opt-in to. Likely combines with compiler warnings and static analysis to encourage that use. (Also syntax is still open for debate)
- pjmlp 2mo ago
  Check the WG21 mailing proposals. I was for Safe C++ paper, based on Circle experience, but it was shot down due to politics. So we're left with the profiles camp actually delivering, followed by the remaining compilers caring to actually implement them, otherwise it will be static and dynamic analysis as usual.
  - will4274 2mo ago
    It wasn't shot down due to politics. It was shot down because it solved the wrong problem.
    - pjmlp 2mo ago
      Yeah, that is why there was a paper created specifically to kill any other proposal, by the profiles folks with WG21 majority, and ironically profiles are just as annotation heavy, but since it is profiles, it is alright. I call that politics, and in the end the most likely outcome is that by C++29 nothing will be delivered by the profiles group, that is any better than using clang-tidy already today.
saghm 2mo ago
Classic C++, any issue is at most three years away from going away! There will definitely not be any other issues that are also three years from getting fixed when you reach that year though
- pjmlp 2mo ago
  Actually no, because you are missing the time between standard being ratified and actuality being widely available in all major compilers. By the way, it is also classical Web standards, C, Vulkan, OpenCL, and everything else that has a similar process. Ideally we should have gotten rid of C and C++, but I haven't yet found a better Typescript for C.
  - saghm 2mo ago
    Fair enough, three years might be more of an upper bound than a lower bound. And yeah, the issue of having to wait is common to standard-based processes, but I've never seen anything else based on a standard so frequently have people need to jump in and try to dissuade people that issues matter because of the rolling timeline so frequently, regularly, and for such a long time as C++. Obviously it would be unreasonable to expect it to become perfect and not need any more changes, but like, I was hearing people complain about various aspects of `unique_ptr` a decade ago, and it seems like we're not even past that yet.