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• Rust has the same memory problem as C and C++ - 2 Updates

Rust has the same memory problem as C and C++

Juha Nieminen <nospam@thanks.invalid>: Apr 27 12:06PM > Another is that C++ string literals are const, so this: > char *s = "hello"; > is invalid C++.   Wouldn't that be UB even in C?   (Ok, using a non-const pointer to point to a string literaly is not in itsef UB, but if you ever try to modify it...)   I believe that most competent C programmers would never use non-const char*'s to handle string literals (and most competent C compilers will give a huge-ass warning about it).

James Kuyper <jameskuyper@alumni.caltech.edu>: Apr 27 10:11AM -0400 On 4/27/20 8:06 AM, Juha Nieminen wrote: >> char *s = "hello"; >> is invalid C++.   > Wouldn't that be UB even in C?   No, it's code with perfect well-defined behavior. "hello" has the type char[6], and in this context gets implicitly converted into a char* pointing at the first element of that array. In C++, it has the type const char[6], and gets implicitly converted to const char*. Assigning a const char* value to a char* object would violate the rules of either language, but it isn't a const char* in C.   > (Ok, using a non-const pointer to point to a string literaly is not in > itsef UB, but if you ever try to modify it...)   Correct - any attempt to modify that string has undefined behavior. But if no such attempt is made, the behavior is well-defined (though such code is a potential trap for future maintainers of the code).   > I believe that most competent C programmers would never use non-const > char*'s to handle string literals (and most competent C compilers will > give a huge-ass warning about it).   A lot of people don't bother with that; they may not qualify as "competent", but they're quite numerous, and a lot of them seem to be currently earning money writing C code, so it is important to look out for such problems.

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