There is R1 submitted aug-10 ... has not popped up yet ... development is on-going here. R2 is in works.

P2192R1 std::valstat - function return type (Dusan B. Jovanovic)

R2 is submitted 2020-08-14

P2192R2 std::valstat -Transparent Returns Handling (Dusan B. Jovanovic)

P2192R3 is submitted

P2192R3 std::valstat - Returns Handling (Dusan B. Jovanovic)

Mailing list review, 2020-01-11

The author is encouraged to provide more concrete comparison with other papers in that space: P0323, P0709, P1028, etc
It isn't clear what this paper solves that these other works don't and what the trade-offs are. It would, for the same reasons, be useful that an implementation of the proposal be provided. The proposal seems to be both a set of concrete types, but also requirements on types that are not proposed, and that choice needs to be better justified and compared to other works.
Claims about performances should be backed by comparative benchmarks.

Resolution: Update the paper for another round of mailing review

The author is already going in that direction. Many thanks for the prod.

Closing due to more than 1 year of inactivity. Please re-open if further work is expected.