3 ms·

>Namely, conditional compilation was involved, someone made a struct which had a field in it based on whether a preprocessor constant was defined or not No off

>Namely, conditional compilation was involved, someone made a struct which had a field in it based on whether a preprocessor constant was defined or not No offense but this just sounds like bad design. Haskell has the C preprocessor so technically that particular criticism would apply to it too, but nobody would say it's Haskell's problem just because in theory people could use this feature to write terrible code. (I understand maybe this approach was necessary for interfacting with some other vendor/legacy code somewhere, but in that case the fundamental issue is still bad code, not C++: the bad vendor/legacy code).

seoaeu 6y ago
I've seen this sort of thing all the time. Not the part about different preprocessor defines in different files, but about having a struct's contents depend on some compile time conditions. It comes up when you want to track extra debug information but only for debug builds. It comes up if you need to store platform specific information in a common struct. It can come up if you have a major feature that you want to toggle on/off at compile time. Etc.
yakubin 6y ago
> Haskell has the C preprocessor I'm not sure what you mean by that. Are you saying you can use #ifdef, #include etc. in Haskell code? > No offense but this just sounds like bad design. I agree. However that's just one way you get multiple definitions for the same struct. I think a language should detect such an error. It will detect it for functions. If linkers did not detect multiple function definitions, would you shrug it off by saying "having multiple function definitions is bad design"? (I'm asking in a non-accusatory way. I'm not sure how to word the question more gently.) Many of us don't have the luxury of choosing the quality of code we're employed to debug. It would be nice if languages had some rudimentary sanity-checks to, well, preserve our sanity.
- logicchains 6y ago
  >I'm not sure what you mean by that. Are you saying you can use #ifdef, #include etc. in Haskell code? Yep: https://guide.aelve.com/haskell/cpp-vww0qd72 https://guide.aelve.com/haskell/cpp-vww0qd72. >Many of us don't have the luxury of choosing the quality of code we're employed to debug. It would be nice if languages had some rudimentary sanity-checks to, well, preserve our sanity. I agree, I don't think C++ is especially bad in this regard. If people are going to write bad code, they can write it just as well in Java, C#, Python etc., they'll just use different language features to bring about the horrors. No language (apart from maybe Go, in its extreme simplicity) can save us from having to debug bad code.

seoaeu 6y ago

I've seen this sort of thing all the time. Not the part about different preprocessor defines in different files, but about having a struct's contents depend on some compile time conditions. It comes up when you want to track extra debug information but only for debug builds. It comes up if you need to store platform specific information in a common struct. It can come up if you have a major feature that you want to toggle on/off at compile time. Etc.

yakubin 6y ago

> Haskell has the C preprocessor I'm not sure what you mean by that. Are you saying you can use #ifdef, #include etc. in Haskell code? > No offense but this just sounds like bad design. I agree. However that's just one way you get multiple definitions for the same struct. I think a language should detect such an error. It will detect it for functions. If linkers did not detect multiple function definitions, would you shrug it off by saying "having multiple function definitions is bad design"? (I'm asking in a non-accusatory way. I'm not sure how to word the question more gently.) Many of us don't have the luxury of choosing the quality of code we're employed to debug. It would be nice if languages had some rudimentary sanity-checks to, well, preserve our sanity.

logicchains 6y ago
>I'm not sure what you mean by that. Are you saying you can use #ifdef, #include etc. in Haskell code? Yep: https://guide.aelve.com/haskell/cpp-vww0qd72 https://guide.aelve.com/haskell/cpp-vww0qd72. >Many of us don't have the luxury of choosing the quality of code we're employed to debug. It would be nice if languages had some rudimentary sanity-checks to, well, preserve our sanity. I agree, I don't think C++ is especially bad in this regard. If people are going to write bad code, they can write it just as well in Java, C#, Python etc., they'll just use different language features to bring about the horrors. No language (apart from maybe Go, in its extreme simplicity) can save us from having to debug bad code.