<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/73953>73953</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            __cpp_lib_three_way_comparison not defined when it should be
        </td>
    </tr>

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

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

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

<pre>
    https://godbolt.org/z/z67c5EErb

The following code fails the `#error` with `-std=c++20 -stdlib=libc++`:

```
#include <compare>
#include <version>

std::strong_ordering Test(int a, int b) {
  return a <=> b;
}

#if defined(__cpp_impl_three_way_comparison) && \
 !defined(__cpp_lib_three_way_comparison)
#error The library supports three-way comparison but claims it does not
#endif
```
</pre>
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