type Fn[T] = fn (x T, i int) T

fn func[T](x T, i int, f_ Fn[T]) T {
    return f_(x, i)
}

fn f1[T](x T, i int) T {
    return x
}

fn test_generic_fn_variable() {
    ff1 := f1[int]
    ret1 := ff1(1, 11)
    println(ret1)
    assert ret1 == 1

    ff2 := f2[int]
    ret2 := ff2(1, 11)
    println(ret2)
    assert ret2 == 1

    x1 := func[f64](2.0, 3, f1[f64])
    println(x1)
    assert x1 == 2.0

    x2 := func[f64](2.0, 3, f2[f64])
    println(x2)
    assert x2 == 2.0
}

fn f2[T](x T, i int) T {
    return x
}