1const U = union {
 2    a: fn () void,
 3    b: *U,
 4};
 5pub export fn entry() void {
 6    var u: U = undefined;
 7    _ = &u;
 8}
 9
10// error
11//
12// :6:12: error: variable of type 'tmp.U' must be const or comptime
13// :2:8: note: union requires comptime because of this field
14// :2:8: note: use '*const fn () void' for a function pointer type
15// :3:8: note: union requires comptime because of this field