struct Encoder {}

struct Writer {}

struct StructTypePointer[T] {
mut:
    val &T
}

pub fn (e &Encoder) encode_value[T](val T, mut wr Writer) ! {
    assert e.encode_struct[T](val, 1, mut wr)! == 'a'
}

fn (e &Encoder) encode_struct[U](val U, level int, mut wr Writer) !string {
    $for field in U.fields {
        if val.$(field.name) != unsafe { nil } {
            $if field.indirections > 0 {
                assert field.indirections == 1
                return 'a'
            } $else {
                return 'b'
            }
        }
    }
    return 'z'
}

fn test_check() {
    e := Encoder{}
    mut sb := Writer{}

    mut string_initialized_with_reference := 'ads'
    e.encode_value(StructTypePointer[string]{ val: &string_initialized_with_reference }, mut sb) or {}
}