Modern C++ Won't Save Us
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Modern C++ Won't Save Us
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Re: Modern C++ Won't Save Us
#2[deleted]
Re: Modern C++ Won't Save Us
#3There was an article recently about a behavior which in a recent version of C++ was made from defined behavior into undefined behavior, because making it undefined allowed for better compiler optimizations.
I always thought that undefined behaviors were historical accidents. But apparently sometime people just say "hey, lets add a few more undefined behaviors"
This is the insanity of C++
Re: Modern C++ Won't Save Us
#4There was an article recently about a behavior which in a recent version of C++ was made from defined behavior into undefined behavior, because making it undefined allowed for better compiler optimizations. I always thought that undefined behaviors were historical accidents. But apparently sometime people just say "hey, lets add a few more undefined behaviors" This is the insanity of C++
Can you please find a reference? That sounds interesting.
Re: Modern C++ Won't Save Us
#5There was an article recently about a behavior which in a recent version of C++ was made from defined behavior into undefined behavior, because making it undefined allowed for better compiler optimizations. I always thought that undefined behaviors were historical accidents. But apparently sometime people just say "hey, lets add a few more undefined behaviors" This is the insanity of C++
I am happy to be proven wrong but I feel that they’d never change defined behavior to undefined. Unspecified to undefined sounds more likely.
There’s this article [1] about compilers exploiting undefined behavior but ... it’s already undefined behavior.
[1] https://devblogs.microsoft.com/oldnewthing/20140627-00/?p=63...
Re: Modern C++ Won't Save Us
#6What do you need saving from - Ada has existed for nearly 30 years now ; )
Re: Modern C++ Won't Save Us
#7This has been discussed extensively in the C++ community. I think if you need a very safe code, you shouldn't use the string_view or span without thinking about the potential consequences. These are added to the language to prevent memory allocation and data copy for performance critical software.
Herb Sutter has concrete proposals to address this issue and Clang already supports them: https://www.infoworld.com/article/3307522/revised-proposal-c...
Re: Modern C++ Won't Save Us
#8There was an article recently about a behavior which in a recent version of C++ was made from defined behavior into undefined behavior, because making it undefined allowed for better compiler optimizations. I always thought that undefined behaviors were historical accidents. But apparently sometime people just say "hey, lets add a few more undefined behaviors" This is the insanity of C++
This sounds wrong. You're probably thinking of undefined behavior that happened to behave the same across all available C++ compilers, so people began to rely on it. But since it was technically undefined behavior, optimizers were free to take advantage of it, and when they started to it smashed any code that relied on that undefined behavior behaving in a consistent way.
Re: Modern C++ Won't Save Us
#9Today's C++ will be considered a cobbled together relic in a few C++ standards time periods!
Re: Modern C++ Won't Save Us
#10From the article:
> Dereferencing a nullptr gives a segfault (which is not a security issue, except in older kernels).
I know a lot of people make that assumption, and compilers used to work that way pretty reliably, but I'm pretty confident it's not true. With undefined behavior, anything is possible.