struct StructType[T] {
mut:
    val T
}

type SumTypes = StructType[string] | []SumTypes | []string | bool | int | string

pub struct Count {
mut:
    total int
}

// count_chars count json sizen without new encode
pub fn (mut count Count) count_chars[T](val T) {
    $if T is $sumtype {
        $for v in val.variants {
            if val is v {
                // dump(typeof(val).name)
                count.count_chars(val)
            }
        }
    } $else $if T is $struct {
        count.chars_in_struct(val)
    } $else {
    }
}

// chars_in_struct
fn (mut count Count) chars_in_struct[T](val T) {
    $for field in T.fields {
        va := val.$(field.name)
        count.count_chars(va)
        count.count_chars(val.$(field.name))
        assert true
    }
    assert true
}

fn test_main() {
    mut count := Count{}
    count.count_chars(StructType[SumTypes]{ val: '' })
    assert true
}