At that point, it is IMO better to obtain that block from alloca()[1]—it’s not standard, but where it’s available the compiler will treat the result as untyped

At that point, it is IMO better to obtain that block from alloca()[1]—it’s not standard, but where it’s available the compiler will treat the result as untyped for the purposes of aliasing. (If you’re on GCC/LLVM, __builtin_alloca_with_align is also an option, although note that the memory it returns may not outlive the current block—similar to a standard automatic variable, but unlike memory from traditional alloca.) ISO C has a gigantic hole when it comes to obtaining and recycling untyped memory, pretending the hole is not there isn’t going to help. [1] https://nullprogram.com/blog/2019/10/28/ https://nullprogram.com/blog/2019/10/28/, discussed at the time at https://news.ycombinator.com/item?id=21374863 https://news.ycombinator.com/item?id=21374863