Hi,
I have drafted a proposal for standardizing #pragma once. This has been
previously proposed a few years ago and I recognize that on top of being
difficult to standardize, existing opinions on this topic may render the
paper dead on arrival. However, due to its widespread nature and concerns
about portability contributing to it not being used more I think it's worth
revisiting. I have uploaded the first draft at:
https://jeremy-rifkin.github.io/cpp-proposals/drafts/pragma-once-draft-1.html
.

Cheers,
Jeremy