<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/55780>55780</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            "llvm/Support/JSON.h" does not work with C++20
        </td>
    </tr>

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

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

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

<pre>
    https://godbolt.org/z/6dx49xj8M
Breaks alive2, cc @nunoplopes 

TLDR is that `llvm::json::Value` can not be forward-declared.

</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJxdkV1rwyAUhn-NuZEGc5K0yYUX_aCw0W3Qjd1rPG1sbQxq2m6_fiYdDAZ-vPIenveo0qov3obQe5IvCWzjOFolrQmpdcd4-o5zru5FfT9VL4RtCFuuHIqzp8LoKwKBNW0aSgrWDZ3tje3R00fdY_3YbfZUexpaESiZM2OulzErX5687R7qU5gBo0cb0dHOBiqRHqy7CadmChsjHKr0gUsUz1Wd1yIJOhjkBGAiwvZ96HvrQlTP72-vaRsdqmzsZgTerDvTmw4tXRNYxQEsGZz5f_VYMMi0sSPvFztus97ZEzYjW3s_oI-iLBcVS1peA0CpyqLKMCtkUZRYwzxr8kLOK4WVTIyQaDwnZYyFDm90QkRNyk2iOTAAVuYsWwBkdXrIGFsUB2SKKVELjA-LF6FNOvYx_kni-NSSHI4-mkb74P9M4b0-dohTXOSLIbTW8R1KVHjdPyVTOJ-a_wEbk52O">