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Restructuring clauses for C++26 #5315

@jensmaurer

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@jensmaurer
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See #2252 [basic] before [lex]

Maybe also move the preprocessor section near lex or merge both into a new "lexical processing" clause.

[basic] has some details that need to move later, e.g. allocation/deallocation function details should go to "Declarations".

Operator overloading [over.oper] should partially move to [expr] and to "Declarations".

Isn't "[charconv] Primitive numeric conversions" a good fit for Clause 26 "Numerics library"?

keep Utility types: pair, tuple, variant, optional, any, bitset under [utilities], but create a new grouping subclause called "data types".

Maybe put all of locale, regex. std::format under I/O-ish (because locale-using)

Create [text] clause; see #5226 for details.

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added this to the C++26 milestone on Feb 23, 2022
JohelEGP

JohelEGP commented on Feb 24, 2022

@JohelEGP
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Isn't "[charconv] Primitive numeric conversions" a good fit for Clause 26 "Numerics library"?

I think so, too. Currently, it's hard to find. It makes more sense than [text], as text can represent more than just numbers.

Maybe put all of locale, regex. std::format under I/O-ish (because locale-using)

I'm not sure. You can use std::format while avoiding the locale-using overloads. I'd lean more to moving it to [text].

AlisdairM

AlisdairM commented on Mar 14, 2023

@AlisdairM
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[meta] and [concepts] should be adjacent clauses, or [concepts] should become a subclass of [meta] adjacent to [type.traits].

JohelEGP

JohelEGP commented on Mar 14, 2023

@JohelEGP
Contributor

I agree with making [concepts] a subclause. Not much point to a top-level [concepts] if new concepts are, rightfully, placed in more pertinent subclauses. Its title also needs to better reflect that "not all concepts are here!" Perhaps "basic concepts".

AlisdairM

AlisdairM commented on Mar 22, 2023

@AlisdairM
Contributor

Is it time to move the container header synopses closer to where their contents are defined? E.g., [array.syn],[deque.syn],[forward.list.syn],[list.syn], and [vector.syn] are all adjacent at the top of the sequence containers subclause, [sequences], before we start on the definitions in [array] as a sibling node, and similarly for the associative containers, unordered containers, and container adapters. I don't think any other library clause collects header synopses in this way.

jwakely

jwakely commented on Mar 22, 2023

@jwakely
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Yes, the containers structure is weird.

jensmaurer

jensmaurer commented on Jun 29, 2024

@jensmaurer
MemberAuthor

Consensus from 2024-06-28 editorial meeting:

Have a new "text" top-level clause with charconv, formt, text.encoding, re, locale and the C library facilities mentioned in #5226.

New order top-level clauses: Algorithms, Strings, Text, Numerics, Time, I/O

Move [execpol] to the end of algorithms.parallel.

Move debugging to end of diagnostics

Reorder container subclauses (sequential, associative, unordered, adapters) so that the header synopsis comes just before the first "class template X" heading that describes the content of the respective header.

Move type.index to support.rtti and extract its header subclause so that it becomes a sibling of type.index.

jensmaurer

jensmaurer commented on Jun 29, 2024

@jensmaurer
MemberAuthor

@jwakely , please have a look.

AlisdairM

AlisdairM commented on Jun 29, 2024

@AlisdairM
Contributor

We were also broadly in favour of moving <span> and <mdspan> from Container to Utilities, following the other vocabulary types such as tuple, optional, and any. However, there was also concern about too much churn in one standard, so it was agreed we defer that change to C++29.

AlisdairM

AlisdairM commented on Jun 29, 2024

@AlisdairM
Contributor

We also spoke about finding a new top level title for the Metaprogramming Library so that we could incorporate Concepts and place it adjacent to Type Traits. However, we did not find an acceptable solution at this time. It is anticipated that the reflection library will slide into the Metaprogramming Library.

AlisdairM

AlisdairM commented on Jun 29, 2024

@AlisdairM
Contributor

There was no discussion about reordering Core clauses, such as by #2252. Is there time to revisit that in this cycle?

25 remaining items

tkoeppe

tkoeppe commented on Oct 16, 2024

@tkoeppe
Contributor

The reordering of #5315 (comment) is now done.

tkoeppe

tkoeppe commented on Oct 16, 2024

@tkoeppe
Contributor

Consensus from 2024-06-28 editorial meeting:

Have a new "text" top-level clause with charconv, formt, text.encoding, re, locale and the C library facilities mentioned in #5226.

Just to clarify for posterity: "locale" in the above refers to the entire clause [localization], not just its [locale] subclause.

frederick-vs-ja

frederick-vs-ja commented on Oct 17, 2024

@frederick-vs-ja
Contributor

I wonder whether <type_traits> should be placed in "Metaprogramming library", as some utilities in it are actually language-supporting.

jensmaurer

jensmaurer commented on Oct 17, 2024

@jensmaurer
MemberAuthor

@frederick-vs-ja , please consider this "for C++26" activity done and closed. Do we have a similar github issue for C++29 ?

tkoeppe

tkoeppe commented on Oct 17, 2024

@tkoeppe
Contributor

I don't think we have a concrete proposal yet for another major restructuring. The core wording things we've talked about don't affect top-level clauses I believe. We can open an issue once there's some concrete idea that we'd like to pursue.

As for <type_traits> specifically, sure, one could go back and forth about this, but I don't see an urgent defect here. There are multiple pieces of library that have some magic core language interactions (e.g. start_lifetime_as, bit_cast), and I'm not sure we should move all of those into [support]. A large part of <type_traits> consists of pure library machinery (like the transformations), and surely those should not be in [support]. So, I think the status quo is fine. Feel free to bring a more elaborate rationale.

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        Restructuring clauses for C++26 · Issue #5315 · cplusplus/draft