Comment by locknitpicker | Hacker News Reader

Comment by locknitpicker | Hacker News Reader

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> contract annotations scoped at analysis time that can be verified by external tools, such as static analyzers, model checkers, or automatic theorem provers, are incredibly useful.

Yes they would be.

Except that's not the contracts that they tried to force down C++'s throats.

The current contracts proposals features things like throwing exceptions in contract predicates, leaves out basic features such as function pointers, and not to mention that the contract specification alone covers around 5-10% of C++ specification and still glances over most details as being implementation defined.

As everyone is attacking Stroustrup as this master mind behind this opposition, perhaps people should devote some time to read one of the many papers pointing out the many flaws in the proposal. Stroustrup himself features as the coauthor of a few of them. Why is this not a technical discussion but a witch hunt?

As somewhat of an outsider, the C++ spec process seems really strange to me.

It’s weird that major features are designed from start to finish without even having so much as a demo.

It feels like there should be a back and forth process between committee proposal -> experimental impl in a major compiler -> community feedback, and so on.

It sounds like it’s basically the waterfall approach to language design? They write a glorious spec and chuck it out to the world, and hope that compilers can implement it and people actually find it useful. Example: modules.

> It’s weird that major features are designed from start to finish without even having so much as a demo.

Not necessarily. In broad terms, Boost is considered a staging ground for features proposed to C++. Compiler projects also keep up with the standards.

In this case the concept guys continuously dropped the ball on this requirement though. One of the papers pointing the many flaws in the proposal calls out this shortcoming, where contracts have neither a workable reference implementation nor an adequate specification. In fact, they handwaved a lot over details with vague calls to "implementation-defined".

> contract specification alone covers around 5-10% of C++

I have no idea where you read that but it is a blatant lie - easily disproven by the way: N5046 which is pretty close to the C++26 DIS has 2668 pages. P2900R14 has a total of 114 pages, of which ~56 pages are dedicated to proposed wording.

Wording is presented as a diff to the working draft and contains extensive copies of the existing text that is either amended, modified or removed. (Aka: there are no 56 pages of wording).

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