P2347 Argument type deduction for non-trailing parameter packs

[wg21bot]

P2347R0 Argument type deduction for non-trailing parameter packs (Corentin Jabot, Bruno Manganelli)

[wg21bot]

P2347R1 Argument type deduction for non-trailing parameter packs (Corentin Jabot, Bruno Manganelli)

[wg21bot]

P2347R2 Argument type deduction for non-trailing parameter packs (Corentin Jabot, Bruno Manganelli)

[jfbastien]

This was see on the 2021-08-04 EWG telecon.

POLL: as proposed in the paper, support deduced non-terminal pack followed by a parameter with a default argument, for example:

	void log(string_view formatString, auto&&...args, source_location loc = source_location::current());

SF	F	N	A	SA
1	4	6	0	0

Result: consensus.

POLL: we’re interested in seeing an update to P2347r1, knowing that time is limited.

SF	F	N	A	SA
1	5	3	0	0

Result: consensus.