`undefined`: Can this be expected to work?

[Sze]

I haven’t really used Valgrind a lot yet, but if the usecases for this would be caught by using Valgrind or a similar tool than I don’t see a reason for this.

So I think we should try to use Valgrind (maybe even figure out some half or fully automated way to run it) instead of these manual attempts at asserting something like this.

Won't Zig in future will face the same problem with undefined in Javascript

It is illegal behavior and is caught by Valgrind: andy@bark ~/tmp> cat test.zig const std = @import("std"); pub fn main() void { var x: i32 = undefined; x += 2; std.debug.print("{d}", .{x}); } andy@bark ~/tmp> zig build-exe test.zig -target x86_64-linux andy@bark ~/tmp> valgrind ./test ==1375503== Memcheck, a memory error detector ==1375503== Copyright (C) 2002-2024, and GNU GPL'd, by Julian Seward et al. ==1375503== Using Valgrind-3.23.0 and LibVEX; rerun with -h for copyright info…

I guess if this could be detected in form of some safety check in debug mode it would be even better, but I don’t know in which cases that is possible / planned.