<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/81590>81590</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            libc++ formatter concept depends on itself
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            libc++
      </td>
    </tr>

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

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

<pre>
    It is fixable with returning -> decltype(ctx.out()), but something went wrong, other libraries and compilers do not produce such errors.

https://godbolt.org/z/v1b13Mhb3

Localy (msvc library) error is worse (there are no consteval functions)
<details>
 <summary>error localy</summary>
In file included from E:/dev/projects/BC/src/sema.cpp:8:
In file included from E:/dev/projects/BC/include\utility/print.h:3:
C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.36.32532\include\format:649:42: error: call to immediate function 'std::formatter<bc::unresolved_type>::format<std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>, char>>' is not a constant expression
  649 | _Format_ctx.advance_to(_Formatter.format(
  
  </details>


</pre>
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