Certainly the C committee considers standardizing warnings to be a breaking change so that's not always true. [1]
Re: backwards compatibility, that's not really true. ABI compatibility is different than source-level compatibility. If a library or module is built to one language standard, so long as the ABI remains compatible, I think it's fair game to change syntax and semantics when compiling with a newer language release - especially when there's clear and obvious deficiencies in the existing. Obviously, the committee and I disagree on this.
However, my point remains that if you value backwards compatibility above all else, and it's that backwards compatibility that actually prevents you from adding features in a complete and honest way, maybe don't add the feature. Like, if `std::move` is the best you can muster, don't add it! It's not a move! I don't know what it is, but it's definitely not what the label on the tin says.
Backwards compatibility is the reason why C++ became what it is today, and why it prevailed over other (similar/better?) languages designed at the time. Herb Sutter himself discusses this in the talk here: https://herbsutter.com/2020/07/30/c-on-sea-video-posted-brid...
Re: backwards compatibility, that's not really true. ABI compatibility is different than source-level compatibility. If a library or module is built to one language standard, so long as the ABI remains compatible, I think it's fair game to change syntax and semantics when compiling with a newer language release - especially when there's clear and obvious deficiencies in the existing. Obviously, the committee and I disagree on this.
However, my point remains that if you value backwards compatibility above all else, and it's that backwards compatibility that actually prevents you from adding features in a complete and honest way, maybe don't add the feature. Like, if `std::move` is the best you can muster, don't add it! It's not a move! I don't know what it is, but it's definitely not what the label on the tin says.
[1] https://thephd.github.io/your-c-compiler-and-standard-librar...