Span<T>

// A run of an array's elements, seen in place: `span[i]` reads and writes the array, Slice makes a smaller view,
// nothing is copied. A view of a list sees its elements until the list grows.
public struct System.Span<T>
{
    field items: T[]
    field start: i32
    field length: i32
    static method OutOfRange() -> void
    // The whole array.
    constructor Span(array: T[])
    // `count` elements of the array from `from`.
    constructor Span(array: T[], from: i32, count: i32)
    // `span[i]`.
    method At(index: i32) -> T
    // `span[i] = value`.
    method SetAt(index: i32, value: T) -> void
    // The view from `from` to the end, and `count` elements from `from`.
    method Slice(from: i32) -> System.Span<T>
    method Slice(from: i32, count: i32) -> System.Span<T>
    // A new array with the elements.
    method ToArray() -> T[]
    // Copies the elements into `target` (at least as long).
    method CopyTo(target: System.Span<T>) -> void
    // Every element set to `value`.
    method Fill(value: T) -> void
    method Iterator() -> System.SpanIterator<T>
    property Length: i32
    property IsEmpty: bool
    // The array under the view and where the view starts in it (for code that works on arrays).
    property Items: T[]
    property Start: i32
}