wrong result when using std::view::zip

[yuanzihao-1991]

Here is my code compiled with option -std=c++23, gcc 14.2:

#include "timsort.hpp"
#include <array>
#include <iostream>
#include <tuple>
#include <vector>

int main() {
  auto x = std::vector{4, 2, 3, 1};
  auto y = std::array{'A', 'C', 'B', 'D'};
  auto xy = std::views::zip(x, y);

  gfx::timsort(xy, {},
   [](const std::tuple<int &, char &> &a) {
    return std::get<0>(a);
  });

  for (std::tuple<int &, char &> elem : xy) {
    std::cout << std::get<0>(elem) << ' ' << std::get<1>(elem) << ' ' << '\n';
  }
}

Expected result is:

1 D 
2 C 
3 B 
4 A

However, I got

4 A 
2 C 
4 A 
4 A 

[Morwenn]

Hi, and thanks for the bug report!

I confirm the issue, and it looks like a bug since std::ranges::sort works very well there. I am going to investigate the issue.

[Morwenn]

It turns out that I did not handle proxy iterators correctly. I pushed a new commit to branch 3.x.y which fixes the issue.

The pipeline is partly broken because the CI jobs were meant to target C++20 and I will have some additional work to do in that area, but I ran tests locally with GCC 14, and the issues seems fixed.

[yuanzihao-1991]

It turns out that I did not handle proxy iterators correctly. I pushed a new commit to branch 3.x.y which fixes the issue.

The pipeline is partly broken because the CI jobs were meant to target C++20 and I will have some additional work to do in that area, but I ran tests locally with GCC 14, and the issues seems fixed.

Great! Thanks a lot for your quick response and efforts!

[Morwenn]

No problem!

Do you confirm that the issue is fixed on your side? If so, we can close that ticket.

[yuanzihao-1991]

No problem!

Do you confirm that the issue is fixed on your side? If so, we can close that ticket.

Confirmed. Perfect! Thank you!