Paper Forwarding Checklist

The following should be reviewed before taking a forwarding poll:

• Why this facility should go into the standard library?
• Examples?
• Field experience?
  • Implementation experience?
  • Usage experience?
  • Deployment experience?
• Performance considerations?
• constexpr?
• Discussion of prior art?
• Changes Library Evolution previously requested?
• Support for "std::format", "hash", and allocators (if required)?
• Wording?
• Feature test macro?
• Freestanding?