<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/59763>59763</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [libc++][format] Strings inside of `tuple` and `pair` should be escaped
        </td>
    </tr>

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

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

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

<pre>
    Example:
```c++
#include <cstdio>
#include <format>
#include <tuple>
#include <string>
#include <string_view>
#include <utility>

using namespace std;

int main() {
    const tuple t{"_\t_", "_\t_"s};
    const pair p{auto{"_\t_"}, "_\t_"sv};
 puts(format("{}\n{}", t, p).c_str());
}
```

Expected output:
```bash
("_\t_", "_\t_")
("_\t_", "_\t_")
```

Got:
```bash
(_      _, "_\t_")
(_      _, "_\t_")
```

Compiler explorer: https://godbolt.org/z/8MnaMzzvo
Debug-enabled specializations: [[format.formatter.spec]/2.2](http://eel.is/c++draft/format.formatter#spec-2.2)
Parsing format spec for `tuple` and `pair`: [[format.tuple]/7](http://eel.is/c++draft/format.tuple#7)
</pre>
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