https://issues.dlang.org/show_bug.cgi?id=21565
--- Comment #14 from Paul Backus <snarwin+bugzi...@gmail.com> --- (In reply to Steven Schveighoffer from comment #12) > > On the grounds that it's not desirable. It does not cause undefined > behavior, just useless behavior. We are better off disallowing it. "I don't like it" is not a technical argument, and should have no place in a technical discussion. > What does this mean? All individual values are safe according to D. If you really believe this, then you do not understand D's memory-safety system well enough to contribute usefully to this discussion, and I am wasting both my time and yours by continuing to respond. > It's not about being @safe or not. That's why I said the rules are sound. > It's just that the rules leave us with the reality that using such unions > usable in @safe or @trusted code has no utility. If it's "not about being @safe or not", then what on Earth *is* it about? Personally, I think @safe should allow all code that the compiler can prove is memory-safe, regardless of whether you, I, or anyone else thinks it "has utility" or not. I am rather surprised that this is a controversial point of view. --