> std::indirect looks for me like another pointless c++ thing that already works with forward pointer declaration. You can add it to another ton of pointless things C++ adds without fixing the old ones.

For me your comment seems pointless, because std::indirect have a precise and clear problem which it solves. And this is totaly not a "hackery fix of language drawback". In this case language works as intended and std::indirect just close the gap for facility which is still would be written by hands, if there is no std::indirect.