LEWG in Kona:
Define the iterator is not the same as the underlying.
SF F N A SA
0 5 3 2 0

Define the iterator is the same as the underlying.
SF F N A SA
0 1 3 7 1

Leave the iterator unspecified wrt. the underlying.
SF F N A SA
2 9 2 0 1

Delete the constructors for flat_set from containers that are not its container_type.
Unanimous consent

Make the above changes, forward to LWG for C++20.
SF F N A SA
0 5 5 1 0

P1222R2 A Standard flat_set (Zach Laine)

This was not adopted for C++20. Removing the "C++20" label.