d的AA需要同inout正常工作

struct C {
    int[] data;
}
struct S {
    private int[][string] aa;
    inout(C) func(string key) inout {
        return inout(C)(aa[key]);
    }
    inout(C) gunk(string key) inout {
        return inout(C)(aa.get(key, [])); // line 10
    }
}