<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/60336>60336</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Type trait used in concept definition not being transiently pulled into the current module?
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
      </td>
    </tr>

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

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

<pre>
    See the discussion/reduction work done here: 

https://reviews.llvm.org/rG12cb1cb3720de8d164196010123ce1a8901d8122
https://godbolt.org/z/v58x71j4a

This is a regression thanks to that revert, which we unfortunately cannot un-revert.

For some reason, the `common_reference` type-trait isn't being pulled into the current context, which does `import std.functional`. Seemingly, the `assignable_from`/`common_reference_with` from `std.concepts.assignable` is, but not the stuff from `std.type_traits`.

For some reason the sugared version of the concept DID include it somehow, but it isn't clear how.
</pre>
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