Dear Sebastian Wittmeier,

It’s not clear whether you answer this to my suggested solution or OP’s.

If or in case OP’s, it’s theirs to comment.

If or in case the cpass<T> solution, monads aren’t exactly a new idea, Bartosz Milewski has a series describing them; other languages like c— (and it’s syntax sugars, Haskell) were born from it.

Also, making c++ *safer* - which both op and cpass is about and which *is* a consern as Rust is being promoted the fix-it-all versus C++ in US govt and def sectors nowadays (meanwhile xor lists are unsafe{} there for alert list in any hard real time code that needs inversion of sublist in O(1) time, therefore memory-wise not saying not much less effective or - unsafe) - we sometimes have to give some. «Performance first, safety dream» is in CppMusical, C++98 - Track 1. It’s *needed*, and will have been needed even more when we start ising the language for real, like for reasoning about human genome and it’s uses and modifications and consents on it (biotech). And it’s *happening*, whether we like it or not - can’t say haven’t been asked about it on interviews.

Now - cpass and uneval are relatively simple solutions that don’t need yet another spinoff language like Java, wasm, c—, Rust, AspectC++ etc. - all of which were (and could still be, to some extent) ideas based on C++ and most of those ideas could be backported as features, with the way proposed by myself, many of those (and many of the ‘good idea’ proposals) as *library* features. Neither of these change a bit in the grammar: these only specify what the code does.

Btw, CppMusical Track 1, we don’t yet have authentication-authorisation-accounting/auditing (consent and risk) and information privacy primitives in STL, do we? Because can’t say that isn’t an EU expectation in data management - e.g., healthcare data in defense sector, consent to giving birth, health and couples’ private sharing vs. chidren’s rights, to name a few areas that can be efficiently addressed with such content filters [0].

Thanks,
lorro

[0] Author declares possible personal bias as having been contracted out to otherwise proper healthcare meets cloud (meets filesystems, which intermediary didn’t allow to use, despite spoken need from EU regulatory / defense for information autonomy in those cases - this is what I can tell here publicly without violating NDA - NCA is not specified) provider’s healthcare system (and can’t say haven’t trusted it with some his own health data, more to come); also having nonzero patents pending inclusive-or issued.




> On 19 Jul 2026, at 10:34, Sebastian Wittmeier via Std-Proposals <std-proposals_at_[hidden]> wrote:
>
> 
> Features like concepts were not added on a whim:
>
> It took 17 years (!) from 2003 to 2020 from the first paper on concepts to inclusion in the standard.
>
> And the first ideas for it (concept-constrained templates) were from 1986 or even further back.
>
> https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2003/n1510.pdf
>
> For a history see https://arxiv.org/pdf/1201.0027
>
>
>
>
>
> There are three sides of C++: What the language can do (abstract machine) and how to express it (syntax and library additions). It fundamentally changes a proposal, in what category it falls. If a feature can be expressed with hundreds of lines of code. Then it is clear, what it does and how the abstract machine would run it. Then one could discuss how to make it easier to use / accessible and how to write code for it.
>
> If every idea for a syntax change was implemented, C++ would be even more gigantic as it already is. The speed of improvements of C++ is huge, especially considering the ISO process and coordination with that huge ecosystem for a language spanning low-level to high-level and being used in many critical systems. To critically question any change is mandatory.
>
> Also please have some more respect for people on this list trying to express proposals with existing code. They put a lot of effort into it to contribute to the discussion.
>
>
> -----Ursprüngliche Nachricht-----
> Von: Ruud Rietvink via Std-Proposals <std-proposals_at_[hidden]>
> C++ moderators really don't like new keywords or constructions that make
> life easier.
> They make up template constructions to allow the new functionality or
> existing C++ code to implement it in a a roundabout way.
> That's probably the reason why C++ doesn't have things like:
> - properties (get; set;)
> - static constructors
> Instead we get template additions like concepts that may have benefits
> but probably doesn't appeal new developers. Or another type of string or
> map.
> It just gets too complicated to learn it at school, or as a first
> computer language.
>
> C++ is becoming the new Cobol.
>
>
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