struct Set[T] {
pub mut:
    arr []T
}

fn (mut s Set[T]) add(elem T) bool {
    return match s.has(elem) {
        true {
            false
        }
        else {
            s.arr << elem
            true
        }
    }
}

fn (s Set[T]) has(elem T) bool {
    return elem in s.arr
}

fn test_generics_struct_with_array() {
    mut s1 := Set[int]{}
    println('declared a int-Set ${s1}')
    s1.add(1)
    println('the int-Set ${s1}')
    assert s1.arr == [1]

    mut s2 := Set[bool]{}
    println('declared a bool-Set ${s2}')
    s2.add(true)
    println('the bool-Set ${s2}')
    assert s2.arr == [true]

    mut s3 := Set[f64]{}
    println('declared a float-Set ${s3}')
    s3.add(2.22)
    println('the float-Set ${s3}')
    assert s3.arr == [2.22]

    mut s4 := Set[string]{}
    println('declared a string-Set ${s4}')
    s4.add('smth')
    println('the string-Set ${s4} ')
    assert s4.arr == ['smth']
}