struct Arr<T> {
    pub u64: size
    pub *T: data
impl:
    inline fn Arr.size<T>(Arr<T>: arr) -> [u64] arr::size
    inline fn Arr.data<T>(Arr<T>: arr) -> [*T]  arr::data

    fn Arr.set<T>(T: value u64: idx Arr<T>: arr) {
        idx arr::size >= if {
            "Cannot Set: Index out of bounds: " print
            idx println
            1 exit
        }
        value arr::data idx ptr+_mut !
    }

    fn Arr.get_ref<T>(u64: idx Arr<T>: arr) -> [&T] {
        idx arr::size >= if {
            "Cannot Get Ref: Index out of bounds: " print
            idx println
            1 exit
        }
        arr::data idx ptr+
    }

    fn Arr.get_ref_mut<T>(u64: idx Arr<T>: arr) -> [*T] {
        idx arr::size >= if {
            "Cannot Get Ref: Index out of bounds: " print
            idx println
            1 exit
        }
        arr::data idx ptr+_mut
    }

    fn Arr.get<T>(u64: idx Arr<T>: arr) -> [T] {
        idx arr::size >= if {
            "Cannot Get: Index out of bounds: " print
            idx println
            1 exit
        }
        arr::data idx ptr+ @
    }

    fn Arr.rev<T>(Arr<T>: arr) {

        0 arr::size 1 - 
        while over over < do {

            as [start_idx end_idx]
            start_idx arr Arr.get
            end_idx arr Arr.get 
            swap
            end_idx arr Arr.set
            start_idx arr Arr.set

            start_idx 1 +
            end_idx 1 -
        } drop drop

    }

    fn Arr.fill<T>(T: item Arr<T>: arr) {
        0 while dup arr::size < do {
            item over arr Arr.set
            1 +
        } drop
    }
}