1const builtin = @import("builtin");
 2const std = @import("std");
 3const expect = std.testing.expect;
 4
 5test "switch on empty enum" {
 6    const E = enum {};
 7    var e: E = undefined;
 8    _ = &e;
 9    switch (e) {}
10}
11
12test "switch on empty enum with a specified tag type" {
13    const E = enum(u8) {};
14    var e: E = undefined;
15    _ = &e;
16    switch (e) {}
17}
18
19test "switch on empty auto numbered tagged union" {
20    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
21
22    const U = union(enum(u8)) {};
23    var u: U = undefined;
24    _ = &u;
25    switch (u) {}
26}
27
28test "switch on empty tagged union" {
29    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
30
31    const E = enum {};
32    const U = union(E) {};
33    var u: U = undefined;
34    _ = &u;
35    switch (u) {}
36}
37
38test "empty union" {
39    const U = union {};
40    try expect(@sizeOf(U) == 0);
41    try expect(@alignOf(U) == 1);
42}
43
44test "empty extern union" {
45    const U = extern union {};
46    try expect(@sizeOf(U) == 0);
47    try expect(@alignOf(U) == 1);
48}
49
50test "empty union passed as argument" {
51    const U = union(enum) {
52        fn f(u: @This()) void {
53            switch (u) {}
54        }
55    };
56    U.f(@as(U, undefined));
57}
58
59test "empty enum passed as argument" {
60    const E = enum {
61        fn f(e: @This()) void {
62            switch (e) {}
63        }
64    };
65    E.f(@as(E, undefined));
66}