To be "very modern" there would have to be a replacement for the antiquated header files system. Writing function signatures twice isn't modern. Writing all code that uses templates in header files isn't modern. Waiting minutes or hours for my code to compile isn't modern. C++ carries a lot of baggage from the past and that's how it was conceived from the beginning. I'm still using C++ because it's efficient and software is made for users after all.
Very valid points. It looks like the Modules proposal [1] aims to fix some of your points. There certainly is still a lot of work to be done and from what I gathered of the GoingNative panels there is no broad consensus yet on what modules really are. Unfortunately this is still very far away and for now you have to choose between high compile times or a "header-only".
