Changing pointers to include length would require an ABI break on pretty much all platforms. You’d either have to recompile the world or have some sort of bridg

Changing pointers to include length would require an ABI break on pretty much all platforms. You’d either have to recompile the world or have some sort of bridging thing that converts calls from C-with-fat-pointers to standard C. And even recompiling the world wouldn’t be enough, since lots of C code relies on being able to do things like cast pointers to integers, manipulate them as numbers, then cast them back. That’s UB by the standard but platforms and compilers can and often do define that behavior to be something useful. You could say, well, forget binary compatibility and forget nasty code that bit-twiddles pointers. But then why are you even using C? Those are the things that set it apart. Clang is trying to solve this with annotations that allow the programmer to construct fat pointers, either as structures or just implicitly by having the length in a variable somewhere, and enforcing those bounds in the compiler. Seems promising. https://clang.llvm.org/docs/BoundsSafetyImplPlans.html https://clang.llvm.org/docs/BoundsSafetyImplPlans.html