5 ms·

If user(programmer)-behavior is the main problem, and there is claim to a safe C++ subset, then wouldn't it make sense to implement an UNSAFE compiler attribute

If user(programmer)-behavior is the main problem, and there is claim to a safe C++ subset, then wouldn't it make sense to implement an UNSAFE compiler attribute macro, to enable the unsafe features, while turning them off in default compilation mode for new versions of C++?

BearOso 4y ago
There's no unsafe keyword, but most modern C++ people know what is intended to be safe and what isn't, i.e. unique pointers, raii, and bounds-checking accessors. It isn't going to be as strict as Rust, but you get a lot of benefits. Knowing some Rust and how it works, then going back to C++ can help you recognize where to use safer idioms and what's potentially dangerous.
- thecodedmessage 4y ago
  You can still have rogue references to deleted objects in such a situation, or invalidated iterators, or plenty of other undefined behaviors even using just modern C++ features.
- voxelghost 4y ago
  I know there is no unsafe keyword, but I was suggesting one should be added. I am a bit rusty (no pun intended) at the moment, but I have decades-long experience with C++, but not all people do, and all people ,even experienced developers make mistakes or get lazy and take the easy way out from time to time. I think one lesson C++ could take from rust, if nothing else, is that clearly demarking unsafe code sections is beneficial in and of itself. If Strostrup makes the claim that developers using old C features is the main security problem of modern C++ , then an unsafe keyword would guide behavior towards safe usage. #No "old unsafe C" here UNSAFE{ #Full C++, including "old unsafe C" here ... } #No "old unsafe C" here >c++ / treat code as "New Safe C++ only", except for UNSAFE sections >c++ --no-unsafe / treat all code as "New safe C++ only" UNSAFE not allowed >c++ --allow-unsafe / current behavior, allow all C++ including "old unsafe C" in all sections
  - pjmlp 4y ago
    Microsoft is thinking down those lines given, see their "-memory-safe C++" talk at CppCon. https://www.youtube.com/watch?v=ml4t-6bg9-M https://www.youtube.com/watch?v=ml4t-6bg9-M However, this is only one compiler, not ISO C++.

BearOso 4y ago

There's no unsafe keyword, but most modern C++ people know what is intended to be safe and what isn't, i.e. unique pointers, raii, and bounds-checking accessors. It isn't going to be as strict as Rust, but you get a lot of benefits. Knowing some Rust and how it works, then going back to C++ can help you recognize where to use safer idioms and what's potentially dangerous.

thecodedmessage 4y ago
You can still have rogue references to deleted objects in such a situation, or invalidated iterators, or plenty of other undefined behaviors even using just modern C++ features.
voxelghost 4y ago
I know there is no unsafe keyword, but I was suggesting one should be added. I am a bit rusty (no pun intended) at the moment, but I have decades-long experience with C++, but not all people do, and all people ,even experienced developers make mistakes or get lazy and take the easy way out from time to time. I think one lesson C++ could take from rust, if nothing else, is that clearly demarking unsafe code sections is beneficial in and of itself. If Strostrup makes the claim that developers using old C features is the main security problem of modern C++ , then an unsafe keyword would guide behavior towards safe usage. #No "old unsafe C" here UNSAFE{ #Full C++, including "old unsafe C" here ... } #No "old unsafe C" here >c++ / treat code as "New Safe C++ only", except for UNSAFE sections >c++ --no-unsafe / treat all code as "New safe C++ only" UNSAFE not allowed >c++ --allow-unsafe / current behavior, allow all C++ including "old unsafe C" in all sections
- pjmlp 4y ago
  Microsoft is thinking down those lines given, see their "-memory-safe C++" talk at CppCon. https://www.youtube.com/watch?v=ml4t-6bg9-M https://www.youtube.com/watch?v=ml4t-6bg9-M However, this is only one compiler, not ISO C++.