Stroustrup's objection of subversion of, and politicization of the "consensus" process seems pretty darned reasonable to me.
And having two major compiler implementers (Clang and Microsoft) among those opposed to the proposal seems like a very poor sort of consensus to me.
The decision to defer how contracts on virtual methods work until C++29 strikes me as particularly horrifying, and renders the feature completely unusable precisely at the point where it most needed (PIMPL classes where public methods are pure virtual, with implementation provided in a private derived class).
And reminds me of c++20 coroutines, for which we are still awaiting a usable implementation. I made the mistake of actually writing a wrapper library for c++ coroutines. A great feature, but only heroically usable in its c++20 incarnation. (I actually did use it in project, but was left wondering why anyone would actually release THAT feature without a supporting class library). Implementation details were shocking, and awful, and insufficiently specified. And I would be completely amazed if my wrapper library continues to work with C++26.
God willing, C++26 will provide an implementation that allows us to sanely use coroutines in message pumps and thread pools soon (such a great feature!), if the standards committee, God Willing, takes the right and good and sensible path of removing contracts from C++26 so that we can get the structured concurrency library.
All in all, I can't help wondering whether the C++ standard doesn't need "Experimental Features" like Java has. It's certainly interesting to see how The Who Must Not Be Named (Oracle) uses experimental features, some of which have existed in experimental status across four or five Java releases. C++20 coroutines and contracts would have been perfect candidates for "experimental C++ features", that can be tested and hardened and have breaking ABI changes made as necessary and appropriate.
> welcome a contracts design that is simple, and “marketed” as just a debug aid
The operative word would be "simple". It's hard to imagine that the feature would require 56 (!!) pages of specifications if the constness rule were omitted. Who the heck ordered that!!??
The better question you should ask is: who determined that number and put it in their paper with a straight face?
Yes, the section on wording in P2900 is physically 56 pages. That's not 56 pages of new wording though.
For those unaware: Wording is always presented as a diff to the working draft. Apart from new sections that have to be added for contracts, those 56 pages replicate existing pages of the draft verbatim as context for their changes, which often boil down to: adding a bullet point to a list (e.g. extending the list of keywords), adding a sentence to a pre-existing paragraph (e.g. extending the syntax for lambdas), etc.
You could probably condense the wording down quite a bit, it would be harder to follow what is going on with the changes, but apparently that's what some people who just count page numbers would prefer.