<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/59592>59592</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clang behaves different using libstdc++ and libc++
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          c8ef
      </td>
    </tr>
</table>

<pre>
    ```c++
#include <ranges>
#include <algorithm>
#include <vector>
#include <cstdint>

constexpr auto foo(std::vector<std::size_t> v1, std::vector<std::size_t> v2) {
 std::vector<std::size_t> res{};
    res.reserve(v1.size() + v2.size());
    std::ranges::sort(v1);
    std::ranges::sort(v2);
 std::ranges::merge(v1, v2, std::back_inserter(res));
    const auto [first, last] = std::ranges::unique(res);
    res.erase(first, last);
 return res;
}

int main() {
    foo(std::vector{3uz, 4uz, 1uz, 2uz, 5uz},
        std::vector{0uz, 3uz, 6uz, 2uz, 7uz, 5uz});
}
```
https://godbolt.org/z/83Kd5dx81


</pre>
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