[dctwin]

The opposite 'toString' problem seems harder - I didn't try, but it should be possible now that std::string is constexpr.

I don't think you could parse it with, say, a class that has a std::string member (because of the transience restriction), but perhaps you can use lambdas that capture that string by reference, and call each other as appropriate?

As for exporting that as some sort of compiler artefact for use elsewhere, I am not sure how you would do that...