use std;

fn check_sort(vec[int] v1, vec[int] v2) {
  auto len = std::vec::len[int](v1);
  fn lteq(&int a, &int b) -> bool {
    ret a <= b;
  }
  auto f = lteq;
  auto v3 = std::sort::merge_sort[int](f, v1);
  auto i = 0u;
  while (i < len) {
    log v3.(i);
    assert (v3.(i) == v2.(i));
    i += 1u;
  }
}

fn main() {
  {
    auto v1 = [3,7,4,5,2,9,5,8];
    auto v2 = [2,3,4,5,5,7,8,9];
    check_sort(v1, v2);
  }

  {
    auto v1 = [1,1,1];
    auto v2 = [1,1,1];
    check_sort(v1, v2);
  }

  {
    let vec[int] v1 = [];
    let vec[int] v2 = [];
    check_sort(v1, v2);
  }

  {
    auto v1 = [9];
    auto v2 = [9];
    check_sort(v1, v2);
  }

  {
    auto v1 = [9,3,3,3,9];
    auto v2 = [3,3,3,9,9];
    check_sort(v1, v2);
  }

}