That's not how the process works.  You need to write a formal proposal.  See https://www.stroustrup.com/how-to-write-a-proposal.pdf

You (or a champion) then need to present the formal proposal to WG21 at a meeting, likely the EWGI subgroup which deals initially with language extensions.  They will then discuss it and take a vote whether they want to consider working on it.

I'd start by writing a draft of the formal proposal and then posting the draft document to std-proposals.  We can let you know the next step once this is done.  For examples of other proposals see https://wg21.link/index.html