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> Compatibility was not broken there Rewriting a codebase that had: #define static_assert(x) ... Was "fun" (tm) (C++11 adds a 2-argument keyword, C++17 add

> Compatibility was not broken there Rewriting a codebase that had: #define static_assert(x) ... Was "fun" (tm) (C++11 adds a 2-argument keyword, C++17 adds a 1-argument overload that finally undoes the need for the rewrite.) I'll also note we have vastly different standards as to what it would take to "fix" C++. atoi("9999999999") can still launch nethack (undefined behavior!), and C++11's response is to add a new overload, atoll. C++17 still doesn't have modules (TRs aside), still has a grammar that's so obscene to try and parse that compilers still disagree on some of the finer points, and still thinks "undefined behavior" is a hip new metal band to name drop for cred, rather than a last resort. This is not to say we shouldn't try to improve the language anyways, but compatibility was and will continue to be broken (hopefully in small ways that generate compile errors), and C++ will continue to suffer from it's initial design, and it will continue to do so for as long as it remains C++.

sqeaky 10y ago
Fix the static assert should have been trivial, it should have been just a find and replace. Just like any other new keyword in any other new update to a language. The only exception might be if you used string concatenation during macro resolution, if that is the case it shouldn't have worked in the first. atoi causing undefined is not a real complaint because it has always caused undefined behavior. You can't blame changing that on the standard or the new version of C++ because it was already allowed to change with every execution of the program. Trying to fix non-determinism is a good thing because well formed code should already be avoiding these undefined behaviors. Why do and others try to complain when you use undefined behavior and are surprised when it changes in undefined ways? You specifically asked to not be able to know the answer.
- MaulingMonkey 10y ago
  > Fix the static assert should have been trivial, it should have been just a find and replace. Merge conflicts are the gift that just keeps on giving. Every refactor on another branch touching the same code is now a conflict. Any branch doing a search and replace slightly differently (say, whitespacing) is now a conflict. Have you ever had to resolve so many of these conflicts that you started accidentally misresolving even the trivial ones? I have. The nontrivial ones can become much harder to code review (e.g. two branches refactored code in the same file, possibly already causing a merge conflict, now complicated by 'spurious' conflicts unrelated to that refactoring.) Guess how I found out that P4Diff's UI was buggy and could corrupt your local changes? ...a similarly 'trivial' search and replace for logging functions. The static_assert one actually wasn't really that bad ;). Still not 'trivial' though. > [...] atoi [...] You can't blame changing that on the standard That wasn't my intent. My intent was to point out broken behavior that the standard decided to double down (by adding atoll) on instead of fixing (by, say, deprecating atoi, like your compiler or programming standard should.) atoi causing UB is still a real complaint - just not a broken compatibility complaint. > Why do [you] and others try to complain when you use undefined behavior and are surprised when it changes in undefined ways? You specifically asked to not be able to know the answer. I don't? You're perhaps thinking of unspecified behavior. Undefined behavior is a damn sight worse than "asking not to know the answer": it's accidentally telling the compiler to generate a broken program that could do anything, for nobody does this intentionally. On the subject of things I do ask: I spend a lot of time on enabling more warnings as errors, using more static analysis tools, new compilers, etc. to try and find every instance of accidental undefined behavior so we can fix it. I'm specifically asking to know about all instances of undefined behavior so we can fix them to not invoke undefined behavior. If I could get a comprehensive answer to this, I'd give C++ a lot less shit. But I cannot get a comprehensive answer to this. There will always be something to slip through the cracks. And other programming languages, taunting me with their lack of undefined behavior. Hell, I'd even settle for a comprehensive answer to "where's all the undefined behavior in my code", and settle for my existing debugging loop when dealing with undefined behavior in third party and system libraries. But I can't even have that on C++ codebases. Why don't you complain about this?
  - sqeaky 10y ago
    > Merge conflicts are the gift that just keeps on giving. I deeply sympathize you on this. I see now what you meant on atoi, I suppose I agree. I prefer boost::lexical_cast or rolling my own when performance matters and type safety is in question. I was too harsh in my earlier comment and I see I wrote at least some it in anger and misunderstanding. The fact it is accidental is bad, more compiler warnings should be able to be enabled by default in my opinion that catch this kind of non-sense. I agree it shouldn't be possible to be accidental. I suppose I have had this argument with too many people who see C and C++ as slightly more portable assemblers and grow to rely on specific results of undefined behavior. These people try to defend their right to rely on old and specific undefined behavior. I mistakenly lumped you in with these people incorrectly, please forgive me.
    - MaulingMonkey 10y ago
      Hey, no worries. Undefined behavior gets me angry too ;).

sqeaky 10y ago

Fix the static assert should have been trivial, it should have been just a find and replace. Just like any other new keyword in any other new update to a language. The only exception might be if you used string concatenation during macro resolution, if that is the case it shouldn't have worked in the first. atoi causing undefined is not a real complaint because it has always caused undefined behavior. You can't blame changing that on the standard or the new version of C++ because it was already allowed to change with every execution of the program. Trying to fix non-determinism is a good thing because well formed code should already be avoiding these undefined behaviors. Why do and others try to complain when you use undefined behavior and are surprised when it changes in undefined ways? You specifically asked to not be able to know the answer.

MaulingMonkey 10y ago
> Fix the static assert should have been trivial, it should have been just a find and replace. Merge conflicts are the gift that just keeps on giving. Every refactor on another branch touching the same code is now a conflict. Any branch doing a search and replace slightly differently (say, whitespacing) is now a conflict. Have you ever had to resolve so many of these conflicts that you started accidentally misresolving even the trivial ones? I have. The nontrivial ones can become much harder to code review (e.g. two branches refactored code in the same file, possibly already causing a merge conflict, now complicated by 'spurious' conflicts unrelated to that refactoring.) Guess how I found out that P4Diff's UI was buggy and could corrupt your local changes? ...a similarly 'trivial' search and replace for logging functions. The static_assert one actually wasn't really that bad ;). Still not 'trivial' though. > [...] atoi [...] You can't blame changing that on the standard That wasn't my intent. My intent was to point out broken behavior that the standard decided to double down (by adding atoll) on instead of fixing (by, say, deprecating atoi, like your compiler or programming standard should.) atoi causing UB is still a real complaint - just not a broken compatibility complaint. > Why do [you] and others try to complain when you use undefined behavior and are surprised when it changes in undefined ways? You specifically asked to not be able to know the answer. I don't? You're perhaps thinking of unspecified behavior. Undefined behavior is a damn sight worse than "asking not to know the answer": it's accidentally telling the compiler to generate a broken program that could do anything, for nobody does this intentionally. On the subject of things I do ask: I spend a lot of time on enabling more warnings as errors, using more static analysis tools, new compilers, etc. to try and find every instance of accidental undefined behavior so we can fix it. I'm specifically asking to know about all instances of undefined behavior so we can fix them to not invoke undefined behavior. If I could get a comprehensive answer to this, I'd give C++ a lot less shit. But I cannot get a comprehensive answer to this. There will always be something to slip through the cracks. And other programming languages, taunting me with their lack of undefined behavior. Hell, I'd even settle for a comprehensive answer to "where's all the undefined behavior in my code", and settle for my existing debugging loop when dealing with undefined behavior in third party and system libraries. But I can't even have that on C++ codebases. Why don't you complain about this?
- sqeaky 10y ago
  > Merge conflicts are the gift that just keeps on giving. I deeply sympathize you on this. I see now what you meant on atoi, I suppose I agree. I prefer boost::lexical_cast or rolling my own when performance matters and type safety is in question. I was too harsh in my earlier comment and I see I wrote at least some it in anger and misunderstanding. The fact it is accidental is bad, more compiler warnings should be able to be enabled by default in my opinion that catch this kind of non-sense. I agree it shouldn't be possible to be accidental. I suppose I have had this argument with too many people who see C and C++ as slightly more portable assemblers and grow to rely on specific results of undefined behavior. These people try to defend their right to rely on old and specific undefined behavior. I mistakenly lumped you in with these people incorrectly, please forgive me.
  - MaulingMonkey 10y ago
    Hey, no worries. Undefined behavior gets me angry too ;).