The compatibility breaking C++ is Rust. The problem with breaking some backwards compatibility is that you just broke the ecosystem. And Python3 showed how bre

The compatibility breaking C++ is Rust. The problem with breaking some backwards compatibility is that you just broke the ecosystem. And Python3 showed how breaking some is effectively the same as breaking all, and if you are going to do something small, you might as well do it all because its going to be a pain point for years or decades no matter how much automation tooling you build around the transition. That is made even worse for a compiled language like C++, where if you break headers for some unsupported library it becomes effectively unusable in newer versions.