1const E = enum(u8) {
 2    a,
 3    b,
 4    _,
 5};
 6const U = union(E) {
 7    a: i32,
 8    b: u32,
 9};
10pub export fn entry1() void {
11    const e: E = .b;
12    switch (e) { // error: switch not handling the tag `b`
13        .a, _ => {},
14    }
15}
16pub export fn entry2() void {
17    const u = U{ .a = 2 };
18    switch (u) { // error: `_` prong not allowed when switching on tagged union
19        .a => {},
20        .b, _ => {},
21    }
22}
23
24// error
25//
26// :12:5: error: switch must handle all possibilities
27// :3:5: note: unhandled enumeration value: 'b'
28// :1:11: note: enum 'tmp.E' declared here
29// :18:5: error: '_' prong only allowed when switching on non-exhaustive enums
30// :20:13: note: '_' prong here
31// :18:5: note: consider using 'else'