22.6.3.2 Constructors [variant.ctor] C++N4910:2022 (562) p703.cpp

# はじめに(Introduction)

N4910  Working Draft, Standard for Programming Language C++

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/n4910.pdf

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  

https://qiita.com/kaizen_nagoya/items/fc957ddddd402004bb91

### C++N4741, 2018 Standard Working Draft on ISO/IEC 14882 sample code compile list
https://qiita.com/kaizen_nagoya/items/3294c014044550896010

### 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++
https://qiita.com/kaizen_nagoya/items/685b5c1a2c17c1bf1318

## 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.

# 22.6.3.2 Constructors [variant.ctor] C++N4910:2022 (562) p703.cpp

## 算譜(source code)

```c++:p703.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 = "22.6.3.2 Constructors [variant.ctor] C++N4910:2022 (562) p703.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 <optional>
#include <memory>
#include <typeinfo>

using namespace std;

// Example 1
constexpr variant() noexcept(see_below);
// Constraints: is_default_constructible_v<T0> is true.
// Effects: Constructs a variant holding a value-initialized value of type T0.
// Postconditions: valueless_by_exception() is false and index() is 0.
// Throws: Any exception thrown by the value-initialization of T0.
// Remarks: This function is constexpr if and only if the value-initialization of the alternative type T0 would satisfy the requirements for a constexpr function. The exception specification is equivalent to is_nothrow_default_constructible_v<T0 >.
// [Note 1: See also class monostate.
constexpr variant(const variant& w);
// Effects: If w holds a value, initializes the variant to hold the same alternative as w and direct-initializes the contained value with get<j>(w), where j is w.index(). Otherwise, initializes the variant to not hold a value.
// Throws: Any exception thrown by direct-initializing any Ti for all i.
// Remarks: This constructor is defined as deleted unless is_copy_constructible_v<Ti> is true for all
//  If is_trivially_copy_constructible_v<Ti> is true for all i, this constructor is trivial.
constexpr variant(variant&& w) noexcept(see below);
// Constraints: is_move_constructible_v<Ti> is true for all i.
// Effects: If w holds a value, initializes the variant to hold the same alternative as w and direct-initializes the contained value with get<j>(std::move(w)), where j is w.index(). Otherwise, initializes the variant to not hold a value.
// Throws: Any exception thrown by move-constructing any Ti for all i.
// Remarks: The exception specification is equivalent to the logical AND of is_nothrow_move_con- structible_v<Ti> for all i. If is_trivially_move_constructible_v<Ti> is true for all i, this constructor is trivial.
template<class T> constexpr variant(T&& t) noexcept(see below);
// Let Tj be a type that is determined as follows: build an imaginary function FUN(Ti) for each alternative type Ti for which Ti x[] = {std::forward<T>(t)}; is well-formed for some invented variable x. The overload FUN(Tj) selected by overload resolution for the expression FUN(std::forward<T>(t)) defines the alternative Tj which is the type of the contained value after construction.
// Constraints:
// — sizeof...(Types) is nonzero,
// — is_same_v<remove_cvref_t<T>, variant> is false,
// — remove_cvref_t<T> is neither a specialization of in_place_type_t nor a specialization of in_- place_index_t,
// — is_constructible_v<Tj, T> is true, and
// — the expression FUN(std::forward<T>(t)) (with FUN being the above-mentioned set of imaginary functions) is well-formed.
// [Note 2:
variant<string, string> v("abc");
// is ill-formed, as both alternative types have an equally viable constructor for the argument. —end note] Effects: Initializes *this to hold the alternative type Tj and direct-non-list-initializes the contained
value with std::forward<T>(t).
// Postconditions: holds_alternative<Tj>(*this) is true.
// Throws: Any exception thrown by the initialization of the selected alternative Tj.
// Remarks: The exception specification is equivalent to is_nothrow_constructible_v<Tj, T>. If Tj’s selected constructor is a constexpr constructor, this constructor is a constexpr constructor.
template<class T, class... Args> constexpr explicit variant(in_place_type_t<T>, Args&&... args);
// Constraints:
// — There is exactly one occurrence of T in Types... and
// — is_constructible_v<T, Args...> is true.
// Effects: Direct-non-list-initializes the contained value of type T with std::forward<Args>(args)....
// Postconditions: holds_alternative<T>(*this) is true.
// Throws: Any exception thrown by calling the selected constructor of T.
// Remarks: If T’s selected constructor is a constexpr constructor, this constructor is a constexpr constructor.
template<class T, class U, class... Args>
constexpr explicit variant(in_place_type_t<T>, initializer_list<U> il, Args&&... args);
// Constraints:
// — There is exactly one occurrence of T in Types... and
// — is_constructible_v<T, initializer_list<U>&, Args...> is true.
// Effects: Direct-non-list-initializes the contained value of type T with il, std::forward<Args>( args)....
// Postconditions: holds_alternative<T>(*this) is true.
// Throws: Any exception thrown by calling the selected constructor of T.
// Remarks: If T’s selected constructor is a constexpr constructor, this constructor is a constexpr constructor.
template<size_t I, class... Args> constexpr explicit variant(in_place_index_t<I>, Args&&... args);
// Constraints:
// — I is less than sizeof...(Types) and
// — is_constructible_v<TI, Args...> is true.
// Effects: Direct-non-list-initializes the contained value of type TI with std::forward<Args>(args)....
// Postconditions: index() is I.
// Throws: Any exception thrown by calling the selected constructor of TI.
// Remarks: If TI’s selected constructor is a constexpr constructor, this constructor is a constexpr constructor.
template<size_t I, class U, class... Args>
constexpr explicit variant(in_place_index_t<I>, initializer_list<U> il, Args&&... args);
// Constraints:
// — I is less than sizeof...(Types) and
// — is_constructible_v<TI, initializer_list<U>&, Args...> is true.
// Effects: Direct-non-list-initializes the contained value of type TI with il, std::forward<Args>( args)....
// Postconditions: index() is I.
// Remarks: If TI’s selected constructor is a constexpr constructor, this constructor is a constexpr constructor.
int main() {
    cout  <<  n4910 << endl;
    return EXIT_SUCCESS;
}
```

## 編纂・実行結果(compile and go)

```ubuntu:bash
$ clang++ p703.cpp -std=03 -o p703l -I. -Wall
In file included from p703.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 \
 ^
p703.cpp:28:1: error: unknown type name 'constexpr'
constexpr variant() noexcept(see_below);
^
p703.cpp:28:21: error: expected function body after function declarator
constexpr variant() noexcept(see_below);
                    ^
p703.cpp:35:2: error: unknown type name 'constexpr'
 constexpr variant(const variant& w);
 ^
p703.cpp:35:26: error: unknown type name 'variant'
 constexpr variant(const variant& w);
                         ^
p703.cpp:40:1: error: unknown type name 'constexpr'
constexpr variant(variant&& w) noexcept(see below);
^
p703.cpp:40:29: error: use of undeclared identifier 'w'
constexpr variant(variant&& w) noexcept(see below);
                            ^
p703.cpp:40:31: error: expected ';' after top level declarator
constexpr variant(variant&& w) noexcept(see below);
                              ^
                              ;
p703.cpp:45:19: error: unknown type name 'constexpr'
template<class T> constexpr variant(T&& t) noexcept(see below);
                  ^
p703.cpp:45:38: warning: rvalue references are a C++11 extension [-Wc++11-extensions]
template<class T> constexpr variant(T&& t) noexcept(see below);
                                     ^
p703.cpp:45:43: error: expected ';' at end of declaration
template<class T> constexpr variant(T&& t) noexcept(see below);
                                          ^
                                          ;
p703.cpp:45:53: error: unknown type name 'see'
template<class T> constexpr variant(T&& t) noexcept(see below);
                                                    ^
p703.cpp:45:44: error: C++ requires a type specifier for all declarations
template<class T> constexpr variant(T&& t) noexcept(see below);
                                           ^
p703.cpp:54:1: error: no template named 'variant'
variant<string, string> v("abc");
^
p703.cpp:56:1: error: unknown type name 'value'
value with std::forward<T>(t).
^
p703.cpp:56:11: error: expected ';' after top level declarator
value with std::forward<T>(t).
          ^
          ;
p703.cpp:68:33: warning: variadic templates are a C++11 extension [-Wc++11-extensions]
template<class T, class U, class... Args>
                                ^
p703.cpp:69:3: error: unknown type name 'constexpr'
  constexpr explicit variant(in_place_type_t<T>, initializer_list<U> il, Args&&... args);
  ^
p703.cpp:69:30: error: no template named 'in_place_type_t'
  constexpr explicit variant(in_place_type_t<T>, initializer_list<U> il, Args&&... args);
                             ^
p703.cpp:69:50: error: no template named 'initializer_list'
  constexpr explicit variant(in_place_type_t<T>, initializer_list<U> il, Args&&... args);
                                                 ^
p703.cpp:69:78: warning: rvalue references are a C++11 extension [-Wc++11-extensions]
  constexpr explicit variant(in_place_type_t<T>, initializer_list<U> il, Args&&... args);
                                                                             ^
p703.cpp:77:25: warning: variadic templates are a C++11 extension [-Wc++11-extensions]
template<size_t I, class... Args> constexpr explicit variant(in_place_index_t<I>, Args&&... args);
                        ^
p703.cpp:77:35: error: unknown type name 'constexpr'
template<size_t I, class... Args> constexpr explicit variant(in_place_index_t<I>, Args&&... args);
                                  ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
4 warnings and 20 errors generated.
$ clang++ p703.cpp -std=2b -o p703l -I. -Wall
p703.cpp:28:30: error: use of undeclared identifier 'see_below'
constexpr variant() noexcept(see_below);
                             ^
p703.cpp:28:11: error: C++ requires a type specifier for all declarations
constexpr variant() noexcept(see_below);
~~~~~~~~~ ^
p703.cpp:35:26: error: unknown type name 'variant'
 constexpr variant(const variant& w);
                         ^
p703.cpp:35:12: error: C++ requires a type specifier for all declarations
 constexpr variant(const variant& w);
 ~~~~~~~~~ ^
p703.cpp:40:11: error: C++ requires a type specifier for all declarations
constexpr variant(variant&& w) noexcept(see below);
~~~~~~~~~ ^
p703.cpp:40:29: error: use of undeclared identifier 'w'
constexpr variant(variant&& w) noexcept(see below);
                            ^
p703.cpp:40:31: error: expected ';' after top level declarator
constexpr variant(variant&& w) noexcept(see below);
                              ^
                              ;
p703.cpp:45:53: error: use of undeclared identifier 'see'
template<class T> constexpr variant(T&& t) noexcept(see below);
                                                    ^
p703.cpp:45:57: error: expected ')'
template<class T> constexpr variant(T&& t) noexcept(see below);
                                                        ^
p703.cpp:45:52: note: to match this '('
template<class T> constexpr variant(T&& t) noexcept(see below);
                                                   ^
p703.cpp:45:29: error: C++ requires a type specifier for all declarations
template<class T> constexpr variant(T&& t) noexcept(see below);
                  ~~~~~~~~~ ^
p703.cpp:54:1: error: no template named 'variant'
variant<string, string> v("abc");
^
p703.cpp:56:1: error: unknown type name 'value'
value with std::forward<T>(t).
^
p703.cpp:56:11: error: expected ';' after top level declarator
value with std::forward<T>(t).
          ^
          ;
p703.cpp:56:25: error: use of undeclared identifier 'T'
value with std::forward<T>(t).
                        ^
p703.cpp:69:22: error: C++ requires a type specifier for all declarations
  constexpr explicit variant(in_place_type_t<T>, initializer_list<U> il, Args&&... args);
  ~~~~~~~~~~~~~~~~~~ ^
p703.cpp:77:54: error: C++ requires a type specifier for all declarations
template<size_t I, class... Args> constexpr explicit variant(in_place_index_t<I>, Args&&... args);
                                  ~~~~~~~~~~~~~~~~~~ ^
p703.cpp:86:22: error: C++ requires a type specifier for all declarations
  constexpr explicit variant(in_place_index_t<I>, initializer_list<U> il, Args&&... args);
  ~~~~~~~~~~~~~~~~~~ ^
17 errors generated.

$ g++ p703.cpp -std=03 -o p703g -I. -Wall
In file included from /usr/local/include/c++/12.1.0/atomic:38,
                 from p703.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 \
      |  ^~~~~
p703.cpp:28:1: warning: identifier 'constexpr' is a keyword in C++11 [-Wc++11-compat]
   28 | constexpr variant() noexcept(see_below);
      | ^~~~~~~~~
p703.cpp:28:21: warning: identifier 'noexcept' is a keyword in C++11 [-Wc++11-compat]
   28 | constexpr variant() noexcept(see_below);
      |                     ^~~~~~~~
p703.cpp:28:1: error: 'constexpr' does not name a type
   28 | constexpr variant() noexcept(see_below);
      | ^~~~~~~~~
p703.cpp:28:1: note: C++11 'constexpr' only available with '-std=c++11' or '-std=gnu++11'
p703.cpp:35:2: error: 'constexpr' does not name a type
   35 |  constexpr variant(const variant& w);
      |  ^~~~~~~~~
p703.cpp:35:2: note: C++11 'constexpr' only available with '-std=c++11' or '-std=gnu++11'
p703.cpp:40:1: error: 'constexpr' does not name a type
   40 | constexpr variant(variant&& w) noexcept(see below);
      | ^~~~~~~~~
p703.cpp:40:1: note: C++11 'constexpr' only available with '-std=c++11' or '-std=gnu++11'
p703.cpp:45:19: error: 'constexpr' does not name a type
   45 | template<class T> constexpr variant(T&& t) noexcept(see below);
      |                   ^~~~~~~~~
p703.cpp:45:19: note: C++11 'constexpr' only available with '-std=c++11' or '-std=gnu++11'
p703.cpp:54:1: error: 'variant' does not name a type
   54 | variant<string, string> v("abc");
      | ^~~~~~~
p703.cpp:56:1: error: 'value' does not name a type
   56 | value with std::forward<T>(t).
      | ^~~~~
p703.cpp:68:33: warning: variadic templates only available with '-std=c++11' or '-std=gnu++11' [-Wc++11-extensions]
   68 | template<class T, class U, class... Args>
      |                                 ^~~
p703.cpp:69:3: error: 'constexpr' does not name a type
   69 |   constexpr explicit variant(in_place_type_t<T>, initializer_list<U> il, Args&&... args);
      |   ^~~~~~~~~
p703.cpp:69:3: note: C++11 'constexpr' only available with '-std=c++11' or '-std=gnu++11'
p703.cpp:77:25: warning: variadic templates only available with '-std=c++11' or '-std=gnu++11' [-Wc++11-extensions]
   77 | template<size_t I, class... Args> constexpr explicit variant(in_place_index_t<I>, Args&&... args);
      |                         ^~~
p703.cpp:77:35: error: 'constexpr' does not name a type
   77 | template<size_t I, class... Args> constexpr explicit variant(in_place_index_t<I>, Args&&... args);
      |                                   ^~~~~~~~~
p703.cpp:77:35: note: C++11 'constexpr' only available with '-std=c++11' or '-std=gnu++11'
p703.cpp:85:34: warning: variadic templates only available with '-std=c++11' or '-std=gnu++11' [-Wc++11-extensions]
   85 | template<size_t I, class U, class... Args>
      |                                  ^~~
p703.cpp:86:3: error: 'constexpr' does not name a type
   86 |   constexpr explicit variant(in_place_index_t<I>, initializer_list<U> il, Args&&... args);
      |   ^~~~~~~~~
p703.cpp:86:3: note: C++11 'constexpr' only available with '-std=c++11' or '-std=gnu++11'

$ g++ p703.cpp -std=2b -o p703g -I. -Wall
p703.cpp:28:30: error: 'see_below' was not declared in this scope
   28 | constexpr variant() noexcept(see_below);
      |                              ^~~~~~~~~
p703.cpp:28:11: error: ISO C++ forbids declaration of 'variant' with no type [-fpermissive]
   28 | constexpr variant() noexcept(see_below);
      |           ^~~~~~~
p703.cpp:35:26: error: 'variant' does not name a type
   35 |  constexpr variant(const variant& w);
      |                          ^~~~~~~
p703.cpp:35:12: error: ISO C++ forbids declaration of 'variant' with no type [-fpermissive]
   35 |  constexpr variant(const variant& w);
      |            ^~~~~~~
p703.cpp:40:11: error: ISO C++ forbids declaration of 'variant' with no type [-fpermissive]
   40 | constexpr variant(variant&& w) noexcept(see below);
      |           ^~~~~~~
p703.cpp:40:19: error: 'constexpr const int variant' redeclared as different kind of entity
   40 | constexpr variant(variant&& w) noexcept(see below);
      |                   ^~~~~~~
p703.cpp:35:12: note: previous declaration 'constexpr int variant(const int&)'
   35 |  constexpr variant(const variant& w);
      |            ^~~~~~~
p703.cpp:40:29: error: 'w' was not declared in this scope
   40 | constexpr variant(variant&& w) noexcept(see below);
      |                             ^
p703.cpp:45:53: error: 'see' was not declared in this scope
   45 | template<class T> constexpr variant(T&& t) noexcept(see below);
      |                                                     ^~~
p703.cpp:45:56: error: expected ')' before 'below'
   45 | template<class T> constexpr variant(T&& t) noexcept(see below);
      |                                                    ~   ^~~~~~
      |                                                        )
p703.cpp:45:57: error: expected initializer before 'below'
   45 | template<class T> constexpr variant(T&& t) noexcept(see below);
      |                                                         ^~~~~
p703.cpp:54:1: error: 'variant<std::string, std::string>' does not name a type
   54 | variant<string, string> v("abc");
      | ^~~~~~~~~~~~~~~~~~~~~~~
p703.cpp:56:1: error: 'value' does not name a type
   56 | value with std::forward<T>(t).
      | ^~~~~
p703.cpp:69:22: error: ISO C++ forbids declaration of 'variant' with no type [-fpermissive]
   69 |   constexpr explicit variant(in_place_type_t<T>, initializer_list<U> il, Args&&... args);
      |                      ^~~~~~~
p703.cpp:69:13: error: 'explicit' outside class declaration
   69 |   constexpr explicit variant(in_place_type_t<T>, initializer_list<U> il, Args&&... args);
      |             ^~~~~~~~
p703.cpp:77:54: error: ISO C++ forbids declaration of 'variant' with no type [-fpermissive]
   77 | template<size_t I, class... Args> constexpr explicit variant(in_place_index_t<I>, Args&&... args);
      |                                                      ^~~~~~~
p703.cpp:77:45: error: 'explicit' outside class declaration
   77 | template<size_t I, class... Args> constexpr explicit variant(in_place_index_t<I>, Args&&... args);
      |                                             ^~~~~~~~
p703.cpp:86:22: error: ISO C++ forbids declaration of 'variant' with no type [-fpermissive]
   86 |   constexpr explicit variant(in_place_index_t<I>, initializer_list<U> il, Args&&... args);
      |                      ^~~~~~~
p703.cpp:86:13: error: 'explicit' outside class declaration
   86 |   constexpr explicit variant(in_place_index_t<I>, initializer_list<U> il, Args&&... args);
      |             ^~~~~~~~

```

## 検討事項(agenda)
コンパイルエラーを取るか、コンパイルエラーの理由を解説する。

<!-- リンクエラーの解説をする。clang++とg++の比較。意味のある出力。
コンパイルエラーを取るか、コンパイルエラーの理由を解説する。-->

# 参考資料(reference)

cpprefjp - C++日本語リファレンス

https://cpprefjp.github.io/

コンパイラの実装状況

https://cpprefjp.github.io/implementation-status.html


typedef は C++11 ではオワコン

https://qiita.com/Linda_pp/items/44a67c64c14cba00eef1

C99からC++14を駆け抜けるC++講座

https://qiita.com/yumetodo/items/e49a673afd9a3ecb81a8


@kazuo_reve 私が効果を確認した「小川メソッド」

https://qiita.com/kazuo_reve/items/a3ea1d9171deeccc04da

## 自己参照(self reference)

ockerにclang

https://qiita.com/kaizen_nagoya/items/8829ffeee397eda50e80

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

https://qiita.com/drafts/059874ea39c4de64c0f7

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

C++N4910:2022 tag follower 200人超えました。ありがとうございます。

https://qiita.com/kaizen_nagoya/items/a63fb96d351ac5c16ff7

C++N4910:2022 tag follower 200人超えました。ありがとうございます。

https://qiita.com/kaizen_nagoya/items/a63fb96d351ac5c16ff7

コピペコンパイルエラーあるある

https://qiita.com/kaizen_nagoya/items/29c832de9d762aed2761

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

https://qiita.com/kaizen_nagoya/items/acb9f1a9b5aad6df06bd

dockerにclang

https://qiita.com/kaizen_nagoya/items/8829ffeee397eda50e80

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

https://qiita.com/drafts/059874ea39c4de64c0f7

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

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

https://qiita.com/kaizen_nagoya/items/483246d40f98abff7ded

C++ sample list

https://qiita.com/kaizen_nagoya/items/54ad75b73825b7c04f86

clang++, g++コンパイルエラー方針の違いの例

https://qiita.com/kaizen_nagoya/items/ea6e5009fe126d270a82

astyle 使ってみた

https://qiita.com/kaizen_nagoya/items/3c9a87a781d53a1a23f3

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 <misra_c.h>
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

DoCAP（ドゥーキャップ）って何ですか？

https://qiita.com/kaizen_nagoya/items/47e0e6509ab792c43327

小川メソッド　覚え（書きかけ）

https://qiita.com/kaizen_nagoya/items/3593d72eca551742df68


 ＜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 　20220726