const Enum = enum(u32) { b, a }; const TaggedUnion = union(Enum) { b: []const u8, a: []const u8, }; pub export fn entry() void { const result = TaggedUnion{ .b = "b" }; _ = result.b; _ = result.a; } pub export fn entry1() void { const result = TaggedUnion{ .b = "b" }; _ = &result.b; _ = &result.a; } // error // // :9:15: error: access of union field 'a' while field 'b' is active // :2:21: note: union declared here // :14:16: error: access of union field 'a' while field 'b' is active // :2:21: note: union declared here