unique_ptr and shared_ptr should format via cast-to-void*. (If no, then formatting unique_ptr and shared_ptr is unsupported.)
SF F N A SA
0 3 5 3 1

Throw invalid_format when encountering a leading 0 in the width specifier for complex.
SF F N A SA
0 1 2 7 0

Update paper with “basic_streambuf is not supported by format.”
Unanimous consent

Make the above clarifications, forward to LWG for C++20.
SF F N A SA
3 7 0 0 0

In theory, adding formatters after we ship C++20 is not a breaking change (so long as users aren't defining their own formatters for our types). This is a nice-to-have for C++20.

P1636R1 Formatters for library types (Lars Gullik Bjønnes)

P1636R2 Formatters for library types (Lars Gullik Bjønnes)

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

LWG will review this on 2021-08-27

LWG review 2021-08-27 and has requested updates:

https://wiki.edg.com/bin/view/Wg21telecons2021/P1636-20210827

SG16 reviewed P1636R2 at its September 22nd, 2021 telecon. The following polls were taken.

Poll 1: Recommend removing the filesystem::path formatter from P1636 "Formatters for library types", and specifically disabling filesystem::path formatting in P2286 "Formatting ranges", pending a proposal with specific design for how to format paths properly.

• Attendance: 12

• SF	F	N	A	SA
  5	5	1	0	0

• Strong consensus in favor.

Victor Zverovich and Peter Brett volunteered to author a proposal to add formatting support for std::filesystem::path with appropriate handling of encoding conversions, non-representable characters, quoting, etc...

This paper has missed c++23 -- unclear if it's still alive.

There's an NB comment requesting this for C++23 (cplusplus/nbballot#410). Library Evolution is yanking this back into our domain. Hopefully we'll be able to cut this down into something we can ship.

I am told a new paper or a revision of this paper will be produced.

Closing, as we now have P2693 #1358, which addresses some of the things in this paper. If someone wants more, please write a new paper or revise this one.