Stable type identifiers: a missing piece for crABI and export

ParaDevOne: > The initial post mentioned dynamic linkage as the motivation, but in post #14 I explicitly distinguished between two separate issues: identifiers linked to ABI compatibility, which is what #3435 addresses, and stable type identification independent of the ABI. What I don't understand is what do you need stable type identification independent of the ABI for. What problem are you trying to solve? What code, program, or system are you trying to write that you can't because you're missing this feature? And how would this feature solve it? ParaDevOne: > Is there any prior work on this? Not that I know of.