Aren't things like bounds checking (#1) an implementation detail? You could implement C with bounds checking if you wanted to. For example you say 'void* can't express size information' - well it can if you chose to implement it as a tuple of address and size. Out of bounds is already undefined, so you could make it abort with a nice error message if you wanted to. There's no need for new language features in order to do that - just change your implementation.