1const Set1 = error{
 2    A,
 3    B,
 4};
 5const Set2 = error{
 6    A,
 7    C,
 8};
 9comptime {
10    _ = @as(Set2, @errorCast(Set1.B));
11}
12
13// test_error='error.B' not a member of error set 'error{A,C}'