<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/91508>91508</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Add feature-test macros from papers to the status page
        </td>
    </tr>

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

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

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

<pre>
    My recent [proposal](https://discourse.llvm.org/t/rfc-improving-the-feature-test-macro-status-page/78327) improves the feature-test macro status page. It would be good to implement all papers/lwg-issue that add FTM to this page. For example
* [P1353R0](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1353r0.html) Missing Feature Test Macros
* [P1902R1](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1902r1.html) Missing feature-test macros 2017-2019

There are most likely more. (This was discovered while investigating #73953.)
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJysU8FupDoQ_BpzaYHsZnjAgcPkRUh7GGkVzQ8YuwecNRjZZmbz9yszSTa7yXElBDKiiqrqahmCGReijlUPDHF2XsslEkNk1WMmtzg53729zQanX7rTC3hStERg1cPq3eqCtKx6ZNhMMa6BlUeGPcNem6Dc5gMV1l7nwvmRYR8Z9v6icjOv3l3NMuZxovxCMm6e8kgh5rNU3uUhyriFfJUjMezrpsSaYQt3HAWIE8FHGOwwuMMgwQr4FuHmNqthIBid0xBdIrA0J_nSWljlSj4w7O1tzE0IG0GcZASpNfTnUwLEybzx9c4D_ZSJgfFHxo8MjymF76Ksyif-VQi3261wKy15iPo1gueoBMM-KMT0wYjppJ1KMt71IBdNOidmz4spzjbZP5kQzDJCf3cO5-T8lJyHvxS1HJ_EP1bU7opajl58UvR5FgGQizrfcXdt-_08kSeQnmB2IYI1P8i-wOw8FcCwOae4bzLAXp8redJwm4wlMMuVQjSjjOl_DMu6bKuyYNhmuit1W7Yyo07UohJNe-A8m7pKSCXq4TKopkUcSs3FwAlVVWuuSF4y0yHHA694I2psq6YYJJaDaMv_2lqWkjQ7cJqlse8dzvaWdK2oeJNZOZANr8tDyyQXtXcr7Q_-zxCtGRTDh_3aV8p3iSgftjGwA7cmxPCbOppoqTtq_WWaF-_m18Lee0kf255t3nZ_Tno0cdqGQrk5Fdxe3x756t0zqbSKu5k03d3PrwAAAP__bAtNdQ">