はじめに(Introduction)

N4910 Working Draft, Standard for Programming Language C++

n4910は、ISO/IEC JTC1 SC22 WG21の作業原案(Working Draft)です。
公式のISO/IEC 14882原本ではありません。
ISO/IEC JTC1 SC22 WG21では、可能な限り作業文書を公開し、幅広い意見を求めています。
一連の記事はコード断片をコンパイルできる形にする方法を検討してコンパイル、リンク、実行して、規格案の原文と処理系(g++, Clang++)との違いを確認し、技術内容を検討し、ISO/IEC JTC1 SC22 WG21にフィードバックするために用います。
また、CERT C++, MISRA C++等のコーディング標準のコード断片をコンパイルする際の参考にさせていただこうと考えています。CERT C++, MISRA C++が標準化の動きとの時間的なずれがあれば確認できれば幸いです。また、boostライブラリとの関連、Linux OS, TOPPERSカーネル、g++(GCC), clang++(LLVM）との関係も調査中です。
何か、抜け漏れ、耳より情報がありましたらおしらせくださると幸いです。

<この項は書きかけです。順次追記します。>

背景(back ground)

C/C++でコンパイルエラーが出ると、途方にくれることがしばしばあります。
何回かに１回は、該当するエラーが検索できます。
ただ、条件が違っていて、そこでの修正方法では目的を達成しないこともしばしばです。いろいろな条件のコンパイルエラーとその対応方法について、広く記録することによって、いつか同じエラーに遭遇した時にやくに立つことを目指しています。

この半年の間で、三度、自分のネットでの記録に助けられたことがあります。
また過去に解決できなかった記録を１０種類以上、最近になって解決できたことがあります。それは、主に次の３つの情報に基づいています。

https://stackoverflow.com
https://cpprefjp.github.io
http://ja.cppreference.com/

また
https://researchmap.jp/joub9b3my-1797580/#_1797580
に記載したサイトのお世話になっています。

作業方針(sequence)

Clang++では-std=c++03, C++2bの2種類
g++では-std=c++03, c++2bの２種類
でコンパイルし、

１）コンパイルエラーを収集する。
２）コンパイルエラーをなくす方法を検討する。
コンパイルエラーになる例を示すだけが目的のコードは、コンパイルエラーをなくすのではなく、コンパイルエラーの種類を収集するだけにする。
文法を示すのが目的のコード場合に、コンパイルエラーをなくすのに手間がかかる場合は、順次作業します。
３）リンクエラーをなくす方法を検討する。
文法を示すのが目的のコード場合に、リンクエラーをなくすのに手間がかかる場合は、順次作業します。
４）意味のある出力を作る。
コンパイル、リンクが通っても、意味のある出力を示そうとすると、コンパイル・リンクエラーが出て収拾できそうにない場合がある。順次作業します。

１）だけのものから４）まで進んだものと色々ある状態です。一歩でも前に進むご助言をお待ちしています。「検討事項」の欄に現状を記録するようにしています。

C++N4910:2022 Standard Working Draft on ISO/IEC 14882(0) sample code compile list

C++N4741, 2018 Standard Working Draft on ISO/IEC 14882 sample code compile list

C++N4606, 2016符号断片編纂一覧(example code compile list)

C++N4606, 2016 Working Draft 2016, ISO/IEC 14882, C++ standard(1) Example code compile list
https://qiita.com/kaizen_nagoya/items/df5d62c35bd6ed1c3d43/

C++N3242, 2011 sample code compile list on clang++ and g++

編纂器(Compiler)

clang++ --version

Debian clang version 14.0.5-++20220610033153+c12386ae247c-1~exp1~20220610153237.151
Target: x86_64-pc-linux-gnu, Thread model: posix, InstalledDir: /usr/bin

g++- --version

g++ (GCC) 12.1.0 Copyright (C) 2022 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

17.6.3.3 Array forms [new.delete.array] C++N4910:2022 (283) p516.cpp

算譜(source code)

p516.cpp

// C++N4910 Committee Draft, Standard for Programming Language C++
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/n4910.pdf
const char * n4910 = "17.6.3.3 Array forms [new.delete.array] C++N4910:2022 (283) p516.cpp";
// Debian clang version 14.0.5-++20220610033153+c12386ae247c-
// g++ (GCC) 12.1.0 Copyright (C) 2022 Free Software Foundation, Inc.
// Edited by Dr. OGAWA Kiyoshi. Compile procedure and results record.
// C++N4910:2022 Standard Working Draft on ISO/IEC 14882(0) sample code compile list
// https://qiita.com/kaizen_nagoya/items/fc957ddddd402004bb91

#include <iostream>
#include <cstdio>
#include <cstdlib> 
#include <cstring>
#include <cassert>
#include <coroutine>
#include <vector>
#include <complex>
#include <map>
#include <atomic>
#include <unordered_map>
#include <typeinfo>

using namespace std;

// Example 1  
[[nodiscard]] void* operator new[](std::size_t size);
// Required behavior: Return a non-null pointer to suitably aligned storage (6.7.5.5), or else return a null pointer. Each of these nothrow versions of operator new[] returns a pointer obtained as if acquired from the (possibly replaced) corresponding non-placement function. This requirement is binding on any replacement versions of these functions.
// Default behavior: Calls operator new[](size), or operator new[](size, alignment), respectively. If the call returns normally, returns the result of that call. Otherwise, returns a null pointer.
   [[nodiscard]] void* operator new[](std::size_t size, std::align_val_t alignment);
// Effects: The allocation functions (6.7.5.5.2) called by the array form of a new-expression (7.6.2.8) to allocate size bytes of storage. The second form is called for a type with new-extended alignment, and the first form is called otherwise.204
// Replaceable: A C++ program may define functions with either of these function signatures, and thereby displace the default versions defined by the C++ standard library.
// Required behavior: Same as for the corresponding single-object forms. This requirement is binding on any replacement versions of these functions.
// Default behavior: Returns operator new(size), or operator new(size, alignment), respectively.
[[nodiscard]] void* operator new[](std::size_t size, const std::nothrow_t&) noexcept;
[[nodiscard]] void* operator new[](std::size_t size, std::align_val_t alignment,
                              const std::nothrow_t&) noexcept;
// Effects: Same as above, except that these are called by a placement version of a new-expression when a C++ program prefers a null pointer result as an error indication, instead of a bad_alloc exception.
// Replaceable: A C++ program may define functions with either of these function signatures, and thereby displace the default versions defined by the C++ standard library.
void operator delete[](void* ptr) noexcept;
void operator delete[](void* ptr, std::size_t size) noexcept;
void operator delete[](void* ptr, std::align_val_t alignment) noexcept;
void operator delete[](void* ptr, std::size_t size, std::align_val_t alignment) noexcept;
// Preconditions: ptr is a null pointer or its value represents the address of a block of memory allocated by an earlier call to a (possibly replaced) operator new[](std::size_t) or operator new[](std::size_t, std::align_val_t) which has not been invalidated by an intervening call to operator delete[]. If the alignment parameter is not present, ptr was returned by an allocation function without an alignment parameter. If present, the alignment argument is equal to the alignment argument passed to the allocation function that returned ptr. If present, the size argument is equal to the size argument passed to the allocation function that returned ptr.
// Effects: The deallocation functions (6.7.5.5.3) called by the array form of a delete-expression to render the value of ptr invalid.
//  Replaceable: A C++ program may define functions with any of these function signatures, and thereby displace the default versions defined by the C++ standard library. If a function without a size parameter is defined, the program should also define the corresponding function with a size parameter. If a function with a size parameter is defined, the program shall also define the corresponding version without the size parameter.
// [Note 1: The default behavior below might change in the future, which will require replacing both deallocation functions when replacing the allocation function. —end note]
// Required behavior: A call to an operator delete[] with a size parameter may be changed to a call to the corresponding operator delete[] without a size parameter, without affecting memory allocation.
// [Note 2: A conforming implementation is for operator delete[](void* ptr, std::size_t size) to simply call operator delete[](ptr). —end note]
// Default behavior: The functions that have a size parameter forward their other parameters to the corresponding function without a size parameter. The functions that do not have a size parameter forward their parameters to the corresponding operator delete (single-object) function.
void operator delete[](void* ptr, const std::nothrow_t&) noexcept;
void operator delete[](void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept;
// Preconditions: ptr is a null pointer or its value represents the address of a block of memory allocated by an earlier call to a (possibly replaced) operator new[](std::size_t) or operator new[](std::size_t, std::align_val_t) which has not been invalidated by an intervening call to operator delete[]. If the alignment parameter is not present, ptr was returned by an allocation function without an alignment parameter. If present, the alignment argument is equal to the alignment argument passed to the allocation function that returned ptr.
// Effects: The deallocation functions (6.7.5.5.3) called by the implementation to render the value of ptr invalid when the constructor invoked from a nothrow placement version of the array new-expression throws an exception.
//  Replaceable: A C++ program may define functions with either of these function signatures, and thereby displace the default versions defined by the C++ standard library.
// Default behavior: Calls operator delete[](ptr), or operator delete[](ptr, alignment), respec- tively.
int main(){
  cout  <<  n4910 << endl;
  return EXIT_SUCCESS;
}

Script

clgc.sh

#!/bin/sh
rm $1l
rm $1g
echo "$ clang++ $1.cpp -std=03 -o $1l -I. -Wall" 
clang++ $1.cpp -std=c++03 -o $1l -I. -Wall
if [  -e $1l ]; then
./$1l 
fi
rm $1l
echo "$ clang++ $1.cpp -std=2b -o $1l -I. -Wall"
clang++ $1.cpp -std=c++2b -o $1l -I. -Wall
if [  -e $1l ]; then
./$1l
fi
echo "\r"
echo "$ g++ $1.cpp -std=03 -o $1g -I. -Wall"
g++ $1.cpp -std=c++03 -o $1g -I. -Wall
if [ -e $1g ]; then
./$1g
fi
rm $1g
echo "\r"
echo "$ g++ $1.cpp -std=2b -o $1g -I. -Wall"
g++ $1.cpp -std=c++2b -o $1g -I. -Wall
if [ -e $1g ]; then
./$1g 
fi

編纂・実行結果(compile and go)

bash

# vi p516.cpp
root@beffd31c1d5f:/home/n4910# ./clgc.sh p516
$ clang++ p516.cpp -std=c++03 -o p516l -I. -Wall
In file included from p516.cpp:19:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/atomic:38:
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/c++0x_warning.h:32:2: error: This file requires compiler and library support for the ISO C++ 2011 standard. This support must be enabled with the -std=c++11 or -std=gnu++11 compiler options.
#error This file requires compiler and library support \
 ^
p516.cpp:26:2: error: expected expression
[[nodiscard]] void* operator new[](std::size_t size);
 ^
p516.cpp:26:15: error: expected unqualified-id
[[nodiscard]] void* operator new[](std::size_t size);
              ^
p516.cpp:29:5: error: expected expression
   [[nodiscard]] void* operator new[](std::size_t size, std::align_val_t alignment);
    ^
p516.cpp:29:18: error: expected unqualified-id
   [[nodiscard]] void* operator new[](std::size_t size, std::align_val_t alignment);
                 ^
p516.cpp:34:2: error: expected expression
[[nodiscard]] void* operator new[](std::size_t size, const std::nothrow_t&) noexcept;
 ^
p516.cpp:34:15: error: expected unqualified-id
[[nodiscard]] void* operator new[](std::size_t size, const std::nothrow_t&) noexcept;
              ^
p516.cpp:35:2: error: expected expression
[[nodiscard]] void* operator new[](std::size_t size, std::align_val_t alignment,
 ^
p516.cpp:35:15: error: expected unqualified-id
[[nodiscard]] void* operator new[](std::size_t size, std::align_val_t alignment,
              ^
p516.cpp:39:35: error: expected function body after function declarator
void operator delete[](void* ptr) noexcept;
                                  ^
p516.cpp:40:53: error: expected function body after function declarator
void operator delete[](void* ptr, std::size_t size) noexcept;
                                                    ^
p516.cpp:41:40: error: no type named 'align_val_t' in namespace 'std'
void operator delete[](void* ptr, std::align_val_t alignment) noexcept;
                                  ~~~~~^
p516.cpp:41:63: error: expected function body after function declarator
void operator delete[](void* ptr, std::align_val_t alignment) noexcept;
                                                              ^
p516.cpp:42:58: error: no type named 'align_val_t' in namespace 'std'
void operator delete[](void* ptr, std::size_t size, std::align_val_t alignment) noexcept;
                                                    ~~~~~^
p516.cpp:42:81: error: expected function body after function declarator
void operator delete[](void* ptr, std::size_t size, std::align_val_t alignment) noexcept;
                                                                                ^
p516.cpp:50:58: error: expected function body after function declarator
void operator delete[](void* ptr, const std::nothrow_t&) noexcept;
                                                         ^
p516.cpp:51:40: error: no type named 'align_val_t' in namespace 'std'
void operator delete[](void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept;
                                  ~~~~~^
p516.cpp:51:86: error: expected function body after function declarator
void operator delete[](void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept;
                                                                                     ^
18 errors generated.
rm: cannot remove 'p516l': No such file or directory
$ clang++ p516.cpp -std=c++2b -o p516l -I. -Wall
17.6.3.3 Array forms [new.delete.array] C++N4910:2022 (283) p516.cpp

$ g++ p516.cpp -std=c++03 -o p516g -I. -Wall
In file included from /usr/local/include/c++/12.1.0/atomic:38,
                 from p516.cpp:19:
/usr/local/include/c++/12.1.0/bits/c++0x_warning.h:32:2: error: #error This file requires compiler and library support for the ISO C++ 2011 standard. This support must be enabled with the -std=c++11 or -std=gnu++11 compiler options.
   32 | #error This file requires compiler and library support \
      |  ^~~~~
p516.cpp:34:77: warning: identifier 'noexcept' is a keyword in C++11 [-Wc++11-compat]
   34 | [[nodiscard]] void* operator new[](std::size_t size, const std::nothrow_t&) noexcept;
      |                                                                             ^~~~~~~~
p516.cpp:26:1: error: expected unqualified-id before '[' token
   26 | [[nodiscard]] void* operator new[](std::size_t size);
      | ^
p516.cpp:29:4: error: expected unqualified-id before '[' token
   29 |    [[nodiscard]] void* operator new[](std::size_t size, std::align_val_t alignment);
      |    ^
p516.cpp:34:1: error: expected unqualified-id before '[' token
   34 | [[nodiscard]] void* operator new[](std::size_t size, const std::nothrow_t&) noexcept;
      | ^
p516.cpp:35:1: error: expected unqualified-id before '[' token
   35 | [[nodiscard]] void* operator new[](std::size_t size, std::align_val_t alignment,
      | ^
p516.cpp:39:35: error: expected initializer before 'noexcept'
   39 | void operator delete[](void* ptr) noexcept;
      |                                   ^~~~~~~~
p516.cpp:40:53: error: expected initializer before 'noexcept'
   40 | void operator delete[](void* ptr, std::size_t size) noexcept;
      |                                                     ^~~~~~~~
p516.cpp:41:40: error: 'std::align_val_t' has not been declared
   41 | void operator delete[](void* ptr, std::align_val_t alignment) noexcept;
      |                                        ^~~~~~~~~~~
p516.cpp:41:63: error: expected initializer before 'noexcept'
   41 | void operator delete[](void* ptr, std::align_val_t alignment) noexcept;
      |                                                               ^~~~~~~~
p516.cpp:42:58: error: 'std::align_val_t' has not been declared
   42 | void operator delete[](void* ptr, std::size_t size, std::align_val_t alignment) noexcept;
      |                                                          ^~~~~~~~~~~
p516.cpp:42:81: error: expected initializer before 'noexcept'
   42 | void operator delete[](void* ptr, std::size_t size, std::align_val_t alignment) noexcept;
      |                                                                                 ^~~~~~~~
p516.cpp:50:58: error: expected initializer before 'noexcept'
   50 | void operator delete[](void* ptr, const std::nothrow_t&) noexcept;
      |                                                          ^~~~~~~~
p516.cpp:51:40: error: 'std::align_val_t' has not been declared
   51 | void operator delete[](void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept;
      |                                        ^~~~~~~~~~~
p516.cpp:51:86: error: expected initializer before 'noexcept'
   51 | void operator delete[](void* ptr, std::align_val_t alignment, const std::nothrow_t&) noexcept;
      |                                                                                      ^~~~~~~~
rm: cannot remove 'p516g': No such file or directory

$ g++ p516.cpp -std=c++2b -o p516g -I. -Wall
17.6.3.3 Array forms [new.delete.array] C++N4910:2022 (283) p516.cpp

検討事項(agenda)

意味のある出力。

参考資料(reference)

cpprefjp - C++日本語リファレンス

コンパイラの実装状況

typedef は C++11 ではオワコン

C99からC++14を駆け抜けるC++講座

自己参照(self reference)

コピペコンパイルエラーあるある

C++ Error Message Collection(1)does not name a type, 11 articles

dockerにclang

docker gnu(gcc/g++) and llvm(clang/clang++)

コンパイル用shell script C版(clangとgcc)とC++版(clang++とg++)

Compare the contents of C++N4910:2022, C++N4741:2018 and C++N4606:2015

C++ sample list

clang++, g++コンパイルエラー方針の違いの例

astyle 使ってみた

C++N4606 Working Draft 2016, ISO/IEC 14882, C++ standardのコード断片をコンパイルするためにしていること
https://qiita.com/kaizen_nagoya/items/a8d7ee2f2e29e76c19c1

コンパイル用shell script C版(clangとgcc)とC++版(clang++とg++)
https://qiita.com/kaizen_nagoya/items/74220c0577a512c2d7da

Clang/Clang++(LLVM) gcc/g++(GNU) コンパイラ警告等比較
https://qiita.com/kaizen_nagoya/items/9a82b958cc3aeef0403f

C++2003とC++2017でコンパイルエラーになるならない事例集
https://qiita.com/kaizen_nagoya/items/a13ea3823441c430edff

Qiitaに投稿するCのStyle例(暫定)
https://qiita.com/kaizen_nagoya/items/946df1528a6a1ef2bc0d

cpprefjpのdecltypeをコンパイル試験
https://qiita.com/kaizen_nagoya/items/090909af702f0d5d8a67

MISRA C++ 5-0-16
https://qiita.com/kaizen_nagoya/items/7df2d4e05db724752a74

C++ Templates Part1 BASICS Chapter 3. Class Templates 3.2 Use of Class Template Stack stack1test.cpp
https://qiita.com/kaizen_nagoya/items/cd5fc49106fad5a4e9ed

ISO/IEC TS 17961:2013 C Secure Coding Rules(1) All list(to be confirmed)
https://qiita.com/kaizen_nagoya/items/54e056195c4f11b850a1

C言語（C++)に対する誤解、曲解、無理解、爽快。
https://qiita.com/kaizen_nagoya/items/3f3992c9722c1cee2e3a

C Puzzle Bookの有り難み5つ、C言語規格及びCコンパイラの特性を認識
https://qiita.com/kaizen_nagoya/items/d89a48c1536a02ecdec9

'wchar.h' file not found で困った clang++ macOS
https://qiita.com/kaizen_nagoya/items/de15cd46d657517fac11

Open POSIX Test Suiteの使い方を調べはじめました
https://qiita.com/kaizen_nagoya/items/644d5e407f5faf96e6dc

MISRA-C 2012 Referenceに掲載している文献の入手可能性を確認
https://qiita.com/kaizen_nagoya/items/96dc8b125e462d5575bb

どうやって MISRA Example Suiteをコンパイルするか
https://qiita.com/kaizen_nagoya/items/fbdbff5ff696e2ca7f00

MISRA C まとめ #include
https://qiita.com/kaizen_nagoya/items/f1a79a7cbd281607c7c9

「C++完全理解ガイド」の同意できること上位10
https://qiita.com/kaizen_nagoya/items/aa5744e0c4a8618c7671

＜この記事は個人の過去の経験に基づく個人の感想です。現在所属する組織、業務とは関係がありません。＞

文書履歴(document history)

ver. 0.01 初稿　20220709