Function croaring_sys::roaring64_bitmap_select

pub unsafe extern "C" fn roaring64_bitmap_select(
    r: *const roaring64_bitmap_t,
    rank: u64,
    element: *mut u64
) -> bool

Selects the element at index ‘rank’ where the smallest element is at index 0. If the size of the bitmap is strictly greater than rank, then this function returns true and sets element to the element of given rank. Otherwise, it returns false.