vlib/v/checker/tests/for_comptime_struct_values_err.vv:5:11: error: iterating over .values is supported only for enums, and Foo is not an enum
    3 | fn (_ Foo) hello() {}
    4 | 
    5 | $for i in Foo.values {
      |           ~~~
    6 |     println(i)
    7 | }