<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/75025>75025</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
             Error in the copyfmt function of cout and cerr
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          W-50243
      </td>
    </tr>
</table>

<pre>
    Some errors occur when I run the following program：

>  cout.copyfmt(cerr);
    cout<<1<<endl;

It failed and output `Segmentation fault` on llvm15, but it works successfully on llvm 14.  [https://godbolt.org/z/qEn15bq9Y](https://godbolt.org/z/qEn15bq9Y). The copyfmt function does not change from llvm14 to llvm15. Did cout and cerr change? Or has something else changed?
</pre>
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