As somebody who used PHP through that transition, I have to say that the 5-7 (skipping 6) transition was especially well handled from my perspective. There was certainly breakage, but the amount of things you had to fix was relatively small.

https://www.php.net/manual/en/migration70.incompatible.php

It was really easy to write code that worked in both 5 and 7. Most of my time was spent waiting for dependencies or frameworks to make the same jump.

Then again, I suppose PHP developers had the hindsight of Python 3 and Perl 6 as a gigantic warning klaxon of what not to do.

One thing specific to C++ is that the main point of discussion isn't necessarily about the language itself, instead it is about breaking the ABI or not moving forward. Breaking the ABI would allow for significant performance improvements, but that would require a huge amount of libraries to be recompiled, which is something a lot of vendors don't want and sometime cannot because sources aren't available anymore.

What about something like this? https://devblogs.microsoft.com/oldnewthing/20040108-00/?p=41...