6.7.7 Temporary objects [class.temporary] C++N4910:2022 (27) p69.cpp

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。

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.

6.7.7 Temporary objects [class.temporary] C++N4910:2022 (27) p69.cpp

算譜(source code)

p69.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 * msg="6.7.7 Temporary objects [class.temporary] C++N4910:2022 (27) p69.cpp";
// Edited by Dr. Ogawa Kiyoshi. Compile procedure and results record.

#include <iostream>
#include <cstdlib> 
#include <cstring>

using namespace std;

// [Example 1 :
class X {
  public:
  X(int);
  X(const X&);
  X& operator=(const X&);
  ~X();
};
class Y {
  public:
  Y(int);
  Y(Y&&);
  ~Y();
};
X f(X);
Y g(Y);
void h() {
  X a(1);
  X b = f(X(2));
  Y c = g(Y(3));
  a = f(a);
}
// [Example 2 :
template<typename T> using id = T;
int i = 1;
int&& a = id<int[3]>{1, 2, 3}[i]; // temporary array has same lifetime as a
const int& b = static_cast<const int&>(0); // temporary int has same lifetime as b
int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
// exactly one of the two temporaries is lifetime-extended
// [Example 3 :
const int& x = (const int&)1; // temporary for value 1 has same lifetime as x
// [Example 4 :
struct S {
  const int& m;
};
const S& s = S{1}; // both S and int temporaries have lifetime of s
// [Example 5 :
struct S5 { int mi; const std::pair<int,int>& mp; };
S5 a5 { 1, {2,3} };
S5* p = new S{ 1, {2,3} }; // creates dangling reference
//  [Example 6 :
struct S6 {
  S6();
  S6(int);
  friend S operator+(const S6&, const S6&);
  ~S6();
};
S6 obj1;
const S& cr = S(16)+S(23);
S6 obj2;
int main() {
  cout <<  msg << 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

# ./clgc.sh p69
rm: cannot remove 'p69l': No such file or directory
rm: cannot remove 'p69g': No such file or directory
$ clang++ p69.cpp -std=03 -o p69l -I. -Wall
p69.cpp:23:6: warning: rvalue references are a C++11 extension [-Wc++11-extensions]
  Y(Y&&);
     ^
p69.cpp:35:33: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
template<typename T> using id = T;
                                ^
p69.cpp:37:4: warning: rvalue references are a C++11 extension [-Wc++11-extensions]
int&& a = id<int[3]>{1, 2, 3}[i]; // temporary array has same lifetime as a
   ^
p69.cpp:37:21: error: expected '(' for function-style cast or type construction
int&& a = id<int[3]>{1, 2, 3}[i]; // temporary array has same lifetime as a
          ~~~~~~~~~~^
p69.cpp:39:4: warning: rvalue references are a C++11 extension [-Wc++11-extensions]
int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
   ^
p69.cpp:39:28: error: expected '(' for function-style cast or type construction
int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
                 ~~~~~~~~~~^
p69.cpp:39:11: error: use of undeclared identifier 'cond'
int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
          ^
p69.cpp:39:28: error: expected ':'
int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
                           ^
                           : 
p69.cpp:39:16: note: to match this '?'
int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
               ^
p69.cpp:39:28: error: expected expression
int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
                           ^
p69.cpp:47:15: error: expected '(' for function-style cast or type construction
const S& s = S{1}; // both S and int temporaries have lifetime of s
             ~^
p69.cpp:49:8: error: implicit default constructor for 'S5' must explicitly initialize the reference member 'mp'
struct S5 { int mi; const std::pair<int,int>& mp; };
       ^
p69.cpp:50:4: note: in implicit default constructor for 'S5' first required here
S5 a5 { 1, {2,3} };
   ^
p69.cpp:49:47: note: declared here
struct S5 { int mi; const std::pair<int,int>& mp; };
                                              ^
p69.cpp:50:6: error: expected ';' after top level declarator
S5 a5 { 1, {2,3} };
     ^
     ;
p69.cpp:44:8: error: implicit default constructor for 'S' must explicitly initialize the reference member 'm'
struct S {
       ^
p69.cpp:51:13: note: in implicit default constructor for 'S' first required here
S5* p = new S{ 1, {2,3} }; // creates dangling reference
            ^
p69.cpp:45:14: note: declared here
  const int& m;
             ^
p69.cpp:51:5: error: cannot initialize a variable of type 'S5 *' with an rvalue of type 'S *'
S5* p = new S{ 1, {2,3} }; // creates dangling reference
    ^   ~~~~~
p69.cpp:51:14: error: expected ';' after top level declarator
S5* p = new S{ 1, {2,3} }; // creates dangling reference
             ^
             ;
p69.cpp:60:15: error: no matching conversion for functional-style cast from 'int' to 'S'
const S& cr = S(16)+S(23);
              ^~~~
p69.cpp:44:8: note: candidate constructor (the implicit copy constructor) not viable: no known conversion from 'int' to 'const S' for 1st argument
struct S {
       ^
p69.cpp:60:21: error: no matching conversion for functional-style cast from 'int' to 'S'
const S& cr = S(16)+S(23);
                    ^~~~
p69.cpp:44:8: note: candidate constructor (the implicit copy constructor) not viable: no known conversion from 'int' to 'const S' for 1st argument
struct S {
       ^
p69.cpp:60:20: error: invalid operands to binary expression ('S' and 'S')
const S& cr = S(16)+S(23);
              ~~~~~^~~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/stl_iterator.h:533:5: note: candidate template ignored: could not match 'reverse_iterator<_Iterator>' against 'S'
    operator+(typename reverse_iterator<_Iterator>::difference_type __n,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6032:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6069:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6085:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.tcc:1152:5: note: candidate template ignored: could not match 'const _CharT *' against 'S'
    operator+(const _CharT* __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.tcc:1172:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
    ^
4 warnings and 14 errors generated.
rm: cannot remove 'p69l': No such file or directory
$ clang++ p69.cpp -std=2b -o p69l -I. -Wall
p69.cpp:39:11: error: use of undeclared identifier 'cond'
int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
          ^
p69.cpp:51:16: warning: temporary bound to reference member of allocated object will be destroyed at the end of the full-expression [-Wdangling-field]
S5* p = new S{ 1, {2,3} }; // creates dangling reference
               ^
p69.cpp:51:19: error: excess elements in struct initializer
S5* p = new S{ 1, {2,3} }; // creates dangling reference
                  ^~~~~
p69.cpp:60:15: error: no matching conversion for functional-style cast from 'int' to 'S'
const S& cr = S(16)+S(23);
              ^~~~
p69.cpp:44:8: note: candidate constructor (the implicit copy constructor) not viable: no known conversion from 'int' to 'const S' for 1st argument
struct S {
       ^
p69.cpp:44:8: note: candidate constructor (the implicit move constructor) not viable: no known conversion from 'int' to 'S' for 1st argument
struct S {
       ^
p69.cpp:44:8: note: candidate constructor (the implicit default constructor) not viable: requires 0 arguments, but 1 was provided
p69.cpp:60:21: error: no matching conversion for functional-style cast from 'int' to 'S'
const S& cr = S(16)+S(23);
                    ^~~~
p69.cpp:44:8: note: candidate constructor (the implicit copy constructor) not viable: no known conversion from 'int' to 'const S' for 1st argument
struct S {
       ^
p69.cpp:44:8: note: candidate constructor (the implicit move constructor) not viable: no known conversion from 'int' to 'S' for 1st argument
struct S {
       ^
p69.cpp:44:8: note: candidate constructor (the implicit default constructor) not viable: requires 0 arguments, but 1 was provided
p69.cpp:60:20: error: invalid operands to binary expression ('S' and 'S')
const S& cr = S(16)+S(23);
              ~~~~~^~~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/stl_iterator.h:533:5: note: candidate template ignored: could not match 'reverse_iterator<_Iterator>' against 'S'
    operator+(typename reverse_iterator<_Iterator>::difference_type __n,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/stl_iterator.h:1573:5: note: candidate template ignored: could not match 'move_iterator<_Iterator>' against 'S'
    operator+(typename move_iterator<_Iterator>::difference_type __n,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6032:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6069:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6085:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6097:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6103:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6109:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6131:5: note: candidate template ignored: could not match 'const _CharT *' against 'S'
    operator+(const _CharT* __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6137:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(_CharT __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6143:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.h:6149:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.tcc:1152:5: note: candidate template ignored: could not match 'const _CharT *' against 'S'
    operator+(const _CharT* __lhs,
    ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/basic_string.tcc:1172:5: note: candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Alloc>' against 'S'
    operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
    ^
1 warning and 5 errors generated.

$ g++ p69.cpp -std=03 -o p69g -I. -Wall
p69.cpp:23:6: error: expected ',' or '...' before '&&' token
   23 |   Y(Y&&);
      |      ^~
p69.cpp:23:3: error: invalid constructor; you probably meant 'Y (const Y&)'
   23 |   Y(Y&&);
      |   ^
p69.cpp:35:22: error: expected unqualified-id before 'using'
   35 | template<typename T> using id = T;
      |                      ^~~~~
p69.cpp:37:4: error: expected unqualified-id before '&&' token
   37 | int&& a = id<int[3]>{1, 2, 3}[i]; // temporary array has same lifetime as a
      |    ^~
p69.cpp:37:30: error: expected unqualified-id before '[' token
   37 | int&& a = id<int[3]>{1, 2, 3}[i]; // temporary array has same lifetime as a
      |                              ^
p69.cpp:39:4: error: expected unqualified-id before '&&' token
   39 | int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
      |    ^~
p69.cpp:39:37: error: expected unqualified-id before '[' token
   39 | int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
      |                                     ^
p69.cpp:47:15: warning: extended initializer lists only available with '-std=c++11' or '-std=gnu++11' [-Wc++11-extensions]
   47 | const S& s = S{1}; // both S and int temporaries have lifetime of s
      |               ^
p69.cpp:50:7: warning: extended initializer lists only available with '-std=c++11' or '-std=gnu++11' [-Wc++11-extensions]
   50 | S5 a5 { 1, {2,3} };
      |       ^
p69.cpp:50:18: warning: extended initializer lists only available with '-std=c++11' or '-std=gnu++11' [-Wc++11-extensions]
   50 | S5 a5 { 1, {2,3} };
      |                  ^
p69.cpp:50:18: warning: extended initializer lists only available with '-std=c++11' or '-std=gnu++11' [-Wc++11-extensions]
p69.cpp:51:14: warning: extended initializer lists only available with '-std=c++11' or '-std=gnu++11' [-Wc++11-extensions]
   51 | S5* p = new S{ 1, {2,3} }; // creates dangling reference
      |              ^
p69.cpp:51:25: error: could not convert '{1, {2, 3}}' from '<brace-enclosed initializer list>' to 'S'
   51 | S5* p = new S{ 1, {2,3} }; // creates dangling reference
      |                         ^
      |                         |
      |                         <brace-enclosed initializer list>
p69.cpp:60:19: error: no matching function for call to 'S::S(int)'
   60 | const S& cr = S(16)+S(23);
      |                   ^
p69.cpp:44:8: note: candidate: 'S::S()'
   44 | struct S {
      |        ^
p69.cpp:44:8: note:   candidate expects 0 arguments, 1 provided
p69.cpp:44:8: note: candidate: 'S::S(const S&)'
p69.cpp:44:8: note:   no known conversion for argument 1 from 'int' to 'const S&'
p69.cpp:60:25: error: no matching function for call to 'S::S(int)'
   60 | const S& cr = S(16)+S(23);
      |                         ^
p69.cpp:44:8: note: candidate: 'S::S()'
   44 | struct S {
      |        ^
p69.cpp:44:8: note:   candidate expects 0 arguments, 1 provided
p69.cpp:44:8: note: candidate: 'S::S(const S&)'
p69.cpp:44:8: note:   no known conversion for argument 1 from 'int' to 'const S&'
rm: cannot remove 'p69g': No such file or directory

$ g++ p69.cpp -std=2b -o p69g -I. -Wall
p69.cpp:39:11: error: 'cond' was not declared in this scope
   39 | int&& c = cond ? id<int[3]>{1, 2, 3}[i] : static_cast<int&&>(0);
      |           ^~~~
p69.cpp:51:25: error: too many initializers for 'S'
   51 | S5* p = new S{ 1, {2,3} }; // creates dangling reference
      |                         ^
p69.cpp:51:25: error: cannot convert 'S*' to 'S5*' in initialization
p69.cpp:60:20: error: no match for 'operator+' (operand types are 'S' and 'S')
   60 | const S& cr = S(16)+S(23);
      |               ~~~~~^~~~~~
      |               |     |
      |               S     S
In file included from /usr/local/include/c++/12.1.0/string:47,
                 from /usr/local/include/c++/12.1.0/bits/locale_classes.h:40,
                 from /usr/local/include/c++/12.1.0/bits/ios_base.h:41,
                 from /usr/local/include/c++/12.1.0/ios:42,
                 from /usr/local/include/c++/12.1.0/ostream:38,
                 from /usr/local/include/c++/12.1.0/iostream:39,
                 from p69.cpp:6:
/usr/local/include/c++/12.1.0/bits/stl_iterator.h:630:5: note: candidate: 'template<class _Iterator> constexpr std::reverse_iterator<_IteratorL> std::operator+(typename reverse_iterator<_IteratorL>::difference_type, const reverse_iterator<_IteratorL>&)'
  630 |     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/stl_iterator.h:630:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'const std::reverse_iterator<_IteratorL>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/stl_iterator.h:1786:5: note: candidate: 'template<class _Iterator> constexpr std::move_iterator<_IteratorL> std::operator+(typename move_iterator<_IteratorL>::difference_type, const move_iterator<_IteratorL>&)'
 1786 |     operator+(typename move_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/stl_iterator.h:1786:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'const std::move_iterator<_IteratorL>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
In file included from /usr/local/include/c++/12.1.0/string:53:
/usr/local/include/c++/12.1.0/bits/basic_string.h:3432:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3432 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3432:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
In file included from /usr/local/include/c++/12.1.0/string:54:
/usr/local/include/c++/12.1.0/bits/basic_string.tcc:606:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
  606 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.tcc:606:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   mismatched types 'const _CharT*' and 'S'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/basic_string.tcc:627:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
  627 |     operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.tcc:627:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3472:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3472 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3472:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3489:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, _CharT)'
 3489 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3489:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3502:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3502 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3502:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3509:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3509 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3509:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3516:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3516 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3516:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3539:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3539 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3539:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   mismatched types 'const _CharT*' and 'S'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3546:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3546 |     operator+(_CharT __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3546:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3553:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const _CharT*)'
 3553 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3553:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   60 | const S& cr = S(16)+S(23);
      |                         ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3560:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, _CharT)'
 3560 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3560:5: note:   template argument deduction/substitution failed:
p69.cpp:60:25: note:   'S' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   60 | const S& cr = S(16)+S(23);
      |           

検討事項(agenda)

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)

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

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https://qiita.com/kaizen_nagoya/items/a8d7ee2f2e29e76c19c1

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https://qiita.com/kaizen_nagoya/items/74220c0577a512c2d7da

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https://qiita.com/kaizen_nagoya/items/9a82b958cc3aeef0403f

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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

文書履歴(document history)

ver. 0.01 初稿 　20220619