On Fri, Feb 27, 2026 at 11:11 AM Jonathan Wakely via Std-Proposals <
std-proposals_at_[hidden]> wrote:

> On Fri, 27 Feb 2026 at 15:07, mm-studios via Std-Proposals <
> std-proposals_at_[hidden]> wrote:
>
>> Hi C++ enthusiasts,
>> This is my first message to std proposals.
>> I wanted to share a few different ideas expressed as 1liners I could work
>> further, in order to find reasons for pursuing them (or not) as formal
>> proposals. These ideas are (succinct):
>>
>>
>> 1. Code verbosity reduction. Ampliate the language allowing custom
>> defaults for const/mut and noexcept/except (include new keywords to express
>> opposite specifiers).
>>
>>
> What does "custom defaults" mean?
>

Presumably something along the lines of `namespace noexcept { /* everything
in this namespace is implicitly noexcept even though I didn't write the
keyword */ }`.

We've had proposals in that general area before; notably 2021's P2350
"constexpr class"
<https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2350r2.pdf>,
which proposed a special syntax for "everything in this *class* is
implicitly *constexpr* even though I didn't write the keyword." See
particularly §6 of P2350, "What about other keywords?" P2350 was deemed "no
consensus," which I think was good for C++, as "constexpr class" would not
be a good feature.

And, as someone else said, 2020's P1881 "Epochs."
<https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1881r1.html>
And arguably "Profiles" (particularly 2019's P1179
<https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1179r1.pdf>,
which proposed (page 14) that within the "Lifetime Safety Profile" the
expressions p+x, x+p, p[x], p+=x, ... should be "errors," i.e., formalizing
syntactic stretches of "dialect" C++ in which certain things are outlawed
and/or certain expressions mean different things than within "vanilla" C++.

–Arthur