12.2.2.3 Operators in expressions [over.match.oper] C++N4910:2022 (183) p325.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。

<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.

12.2.2.3 Operators in expressions [over.match.oper] C++N4910:2022 (183) p325.cpp

算譜(source code)

p325.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 = "12.2.2.3 Operators in expressions [over.match.oper] C++N4910:2022 (183) p325.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
struct String {
    String (const String&);
    String (const char*);
    operator const char* ();
};
String operator + (const String&, const String&);
void f() {
    const char* p= "one" + "two"; // error: cannot add two pointers; overloaded operator+ not considered
// because neither operand has class or enumeration type
    int I = 1 + 1; // always evaluates to 2 even if class or enumeration types exist
}
// that would perform the operation.
// [Example 2:
struct A {
    operator int();
};
A operator+(const A&, const A&);
void m() {
    A a, b;
    a + b; // operator+(a, b) chosen over int(a) + int(b)
}
// [Example 3:
struct X {
    operator double();
};
struct Y {
    operator int*();
};
int *a3 = Y() + 100.0;
int *b3 = Y() + X();
// error: pointer arithmetic requires integral operand // error: pointer arithmetic requires integral operand
// [Note 3: The lookup rules for operators in expressions are different than the lookup rules for operator function names in a function call, as shown in the following example:
struct A3 { };
void operator + (A3, A3);
struct B3 {
    void operator + (B3);
    void f3();
};
A3 a3;
void B3::f3() {
    operator+ (a3,a3);
    a3 + a3;
}
// error: global operator hidden by member // OK, calls global operator+
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

# ./clgc.sh p325
rm: cannot remove 'p325l': No such file or directory
rm: cannot remove 'p325g': No such file or directory
$ clang++ p325.cpp -std=c++03 -o p325l -I. -Wall
In file included from p325.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 \
 ^
p325.cpp:33:22: error: invalid operands to binary expression ('const char[4]' and 'const char[4]')
const char* p= "one" + "two"; // error: cannot add two pointers; overloaded operator+ not considered
               ~~~~~ ^ ~~~~~
p325.cpp:54:17: error: invalid operands to binary expression ('Y' and 'double')
  int *a3 = Y() + 100.0;
            ~~~ ^ ~~~~~
p325.cpp:52:5: note: first operand was implicitly converted to type 'int *'
    operator int*();
    ^
p325.cpp:55:17: error: invalid operands to binary expression ('Y' and 'X')
  int *b3 = Y() + X();
            ~~~ ^ ~~~
p325.cpp:52:5: note: first operand was implicitly converted to type 'int *'
    operator int*();
    ^
p325.cpp:49:5: note: second operand was implicitly converted to type 'double'
    operator double();
    ^
p325.cpp:64:4: error: redefinition of 'a3' with a different type: 'A3' vs 'int *'
A3 a3;
   ^
p325.cpp:54:8: note: previous definition is here
  int *a3 = Y() + 100.0;
       ^
p325.cpp:66:17: error: too many arguments to function call, expected 1, have 2
  operator+ (a3,a3);
  ~~~~~~~~~     ^~
p325.cpp:61:8: note: 'operator+' declared here
  void operator + (B3);
       ^
p325.cpp:67:6: error: invalid operands to binary expression ('int *' and 'int *')
  a3 + a3;
  ~~ ^ ~~
7 errors generated.
rm: cannot remove 'p325l': No such file or directory
$ clang++ p325.cpp -std=c++2b -o p325l -I. -Wall
p325.cpp:33:22: error: invalid operands to binary expression ('const char[4]' and 'const char[4]')
const char* p= "one" + "two"; // error: cannot add two pointers; overloaded operator+ not considered
               ~~~~~ ^ ~~~~~
p325.cpp:54:17: error: invalid operands to binary expression ('Y' and 'double')
  int *a3 = Y() + 100.0;
            ~~~ ^ ~~~~~
p325.cpp:52:5: note: first operand was implicitly converted to type 'int *'
    operator int*();
    ^
p325.cpp:55:17: error: invalid operands to binary expression ('Y' and 'X')
  int *b3 = Y() + X();
            ~~~ ^ ~~~
p325.cpp:52:5: note: first operand was implicitly converted to type 'int *'
    operator int*();
    ^
p325.cpp:49:5: note: second operand was implicitly converted to type 'double'
    operator double();
    ^
p325.cpp:64:4: error: redefinition of 'a3' with a different type: 'A3' vs 'int *'
A3 a3;
   ^
p325.cpp:54:8: note: previous definition is here
  int *a3 = Y() + 100.0;
       ^
p325.cpp:66:17: error: too many arguments to function call, expected 1, have 2
  operator+ (a3,a3);
  ~~~~~~~~~     ^~
p325.cpp:61:8: note: 'operator+' declared here
  void operator + (B3);
       ^
p325.cpp:67:6: error: invalid operands to binary expression ('int *' and 'int *')
  a3 + a3;
  ~~ ^ ~~
6 errors generated.

$ g++ p325.cpp -std=c++03 -o p325g -I. -Wall
In file included from /usr/local/include/c++/12.1.0/atomic:38,
                 from p325.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 \
      |  ^~~~~
p325.cpp: In function 'void f()':
p325.cpp:33:22: error: invalid operands of types 'const char [4]' and 'const char [4]' to binary 'operator+'
   33 | const char* p= "one" + "two"; // error: cannot add two pointers; overloaded operator+ not considered
      |                ~~~~~ ^ ~~~~~
      |                |       |
      |                |       const char [4]
      |                const char [4]
p325.cpp:33:13: warning: unused variable 'p' [-Wunused-variable]
   33 | const char* p= "one" + "two"; // error: cannot add two pointers; overloaded operator+ not considered
      |             ^
p325.cpp:35:5: warning: unused variable 'I' [-Wunused-variable]
   35 | int I = 1 + 1; // always evaluates to 2 even if class or enumeration types exist
      |     ^
p325.cpp: At global scope:
p325.cpp:54:17: error: no match for 'operator+' (operand types are 'Y' and 'double')
   54 |   int *a3 = Y() + 100.0;
      |             ~~~ ^ ~~~~~
      |             |     |
      |             Y     double
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 p325.cpp:10:
/usr/local/include/c++/12.1.0/bits/stl_iterator.h:630:5: note: candidate: 'template<class _Iterator> std::reverse_iterator<_Iterator> std::operator+(typename reverse_iterator<_Iterator>::difference_type, const reverse_iterator<_Iterator>&)'
  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:
p325.cpp:54:19: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'double'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
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> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Alloc>&, const __cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 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:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
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> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
  606 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.tcc:606:5: note:   template argument deduction/substitution failed:
p325.cpp:54:19: note:   mismatched types 'const _CharT*' and 'Y'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.tcc:627:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(_CharT, const __cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
  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:
p325.cpp:54:19: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>' and 'double'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3472:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Alloc>&, 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:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.h:3489:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Alloc>&, _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:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
In file included from p325.cpp:17:
/usr/local/include/c++/12.1.0/complex:332:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator+(const complex<_Tp>&, const complex<_Tp>&)'
  332 |     operator+(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:332:5: note:   template argument deduction/substitution failed:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::complex<_Tp>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/usr/local/include/c++/12.1.0/complex:341:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator+(const complex<_Tp>&, const _Tp&)'
  341 |     operator+(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:341:5: note:   template argument deduction/substitution failed:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::complex<_Tp>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/usr/local/include/c++/12.1.0/complex:350:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator+(const _Tp&, const complex<_Tp>&)'
  350 |     operator+(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:350:5: note:   template argument deduction/substitution failed:
p325.cpp:54:19: note:   mismatched types 'const std::complex<_Tp>' and 'double'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/usr/local/include/c++/12.1.0/complex:451:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator+(const complex<_Tp>&)'
  451 |     operator+(const complex<_Tp>& __x)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:451:5: note:   template argument deduction/substitution failed:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::complex<_Tp>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
p325.cpp:31:10: note: candidate: 'String operator+(const String&, const String&)'
   31 |   String operator + (const String&, const String&);
      |          ^~~~~~~~
p325.cpp:31:22: note:   no known conversion for argument 1 from 'Y' to 'const String&'
   31 |   String operator + (const String&, const String&);
      |                      ^~~~~~~~~~~~~
p325.cpp:42:8: note: candidate: 'A operator+(const A&, const A&)'
   42 |      A operator+(const A&, const A&);
      |        ^~~~~~~~
p325.cpp:42:18: note:   no known conversion for argument 1 from 'Y' to 'const A&'
   42 |      A operator+(const A&, const A&);
      |                  ^~~~~~~~
p325.cpp:55:17: error: no match for 'operator+' (operand types are 'Y' and 'X')
   55 |   int *b3 = Y() + X();
      |             ~~~ ^ ~~~
      |             |     |
      |             Y     X
/usr/local/include/c++/12.1.0/bits/stl_iterator.h:630:5: note: candidate: 'template<class _Iterator> std::reverse_iterator<_Iterator> std::operator+(typename reverse_iterator<_Iterator>::difference_type, const reverse_iterator<_Iterator>&)'
  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:
p325.cpp:55:21: note:   'X' is not derived from 'const std::reverse_iterator<_Iterator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3432:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Alloc>&, const __cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 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:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/bits/basic_string.tcc:606:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
  606 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/bits/basic_string.tcc:606:5: note:   template argument deduction/substitution failed:
p325.cpp:55:21: note:   mismatched types 'const _CharT*' and 'Y'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/bits/basic_string.tcc:627:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(_CharT, const __cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
  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:
p325.cpp:55:21: note:   'X' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3472:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Alloc>&, 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:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/bits/basic_string.h:3489:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Alloc> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Alloc>&, _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:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/complex:332:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator+(const complex<_Tp>&, const complex<_Tp>&)'
  332 |     operator+(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:332:5: note:   template argument deduction/substitution failed:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::complex<_Tp>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/complex:341:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator+(const complex<_Tp>&, const _Tp&)'
  341 |     operator+(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:341:5: note:   template argument deduction/substitution failed:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::complex<_Tp>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/complex:350:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator+(const _Tp&, const complex<_Tp>&)'
  350 |     operator+(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:350:5: note:   template argument deduction/substitution failed:
p325.cpp:55:21: note:   'X' is not derived from 'const std::complex<_Tp>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/complex:451:5: note: candidate: 'template<class _Tp> std::complex<_Tp> std::operator+(const complex<_Tp>&)'
  451 |     operator+(const complex<_Tp>& __x)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:451:5: note:   template argument deduction/substitution failed:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::complex<_Tp>'
   55 |   int *b3 = Y() + X();
      |                     ^
p325.cpp:31:10: note: candidate: 'String operator+(const String&, const String&)'
   31 |   String operator + (const String&, const String&);
      |          ^~~~~~~~
p325.cpp:31:22: note:   no known conversion for argument 1 from 'Y' to 'const String&'
   31 |   String operator + (const String&, const String&);
      |                      ^~~~~~~~~~~~~
p325.cpp:42:8: note: candidate: 'A operator+(const A&, const A&)'
   42 |      A operator+(const A&, const A&);
      |        ^~~~~~~~
p325.cpp:42:18: note:   no known conversion for argument 1 from 'Y' to 'const A&'
   42 |      A operator+(const A&, const A&);
      |                  ^~~~~~~~
p325.cpp:64:4: error: conflicting declaration 'A3 a3'
   64 | A3 a3;
      |    ^~
p325.cpp:54:8: note: previous declaration as 'int* a3'
   54 |   int *a3 = Y() + 100.0;
      |        ^~
p325.cpp: In member function 'void B3::f3()':
p325.cpp:66:13: error: no matching function for call to 'B3::operator+(int*&, int*&)'
   66 |   operator+ (a3,a3);
      |   ~~~~~~~~~~^~~~~~~
p325.cpp:61:8: note: candidate: 'void B3::operator+(B3)'
   61 |   void operator + (B3);
      |        ^~~~~~~~
p325.cpp:61:8: note:   candidate expects 1 argument, 2 provided
p325.cpp:67:6: error: invalid operands of types 'int*' and 'int*' to binary 'operator+'
   67 |   a3 + a3;
      |   ~~ ^ ~~
      |   |    |
      |   int* int*
rm: cannot remove 'p325g': No such file or directory

$ g++ p325.cpp -std=c++2b -o p325g -I. -Wall
p325.cpp: In function 'void f()':
p325.cpp:33:22: error: invalid operands of types 'const char [4]' and 'const char [4]' to binary 'operator+'
   33 | const char* p= "one" + "two"; // error: cannot add two pointers; overloaded operator+ not considered
      |                ~~~~~ ^ ~~~~~
      |                |       |
      |                |       const char [4]
      |                const char [4]
p325.cpp:33:13: warning: unused variable 'p' [-Wunused-variable]
   33 | const char* p= "one" + "two"; // error: cannot add two pointers; overloaded operator+ not considered
      |             ^
p325.cpp:35:5: warning: unused variable 'I' [-Wunused-variable]
   35 | int I = 1 + 1; // always evaluates to 2 even if class or enumeration types exist
      |     ^
p325.cpp: At global scope:
p325.cpp:54:17: error: no match for 'operator+' (operand types are 'Y' and 'double')
   54 |   int *a3 = Y() + 100.0;
      |             ~~~ ^ ~~~~~
      |             |     |
      |             Y     double
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 p325.cpp:10:
/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:
p325.cpp:54:19: note:   mismatched types 'const std::reverse_iterator<_IteratorL>' and 'double'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'double'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
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:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
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:
p325.cpp:54:19: note:   mismatched types 'const _CharT*' and 'Y'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'double'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   'Y' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   'Y' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   mismatched types 'const _CharT*' and 'Y'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'double'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   'Y' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/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:
p325.cpp:54:19: note:   'Y' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
In file included from p325.cpp:17:
/usr/local/include/c++/12.1.0/complex:332:5: note: candidate: 'template<class _Tp> constexpr std::complex<_Tp> std::operator+(const complex<_Tp>&, const complex<_Tp>&)'
  332 |     operator+(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:332:5: note:   template argument deduction/substitution failed:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::complex<_Tp>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/usr/local/include/c++/12.1.0/complex:341:5: note: candidate: 'template<class _Tp> constexpr std::complex<_Tp> std::operator+(const complex<_Tp>&, const _Tp&)'
  341 |     operator+(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:341:5: note:   template argument deduction/substitution failed:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::complex<_Tp>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/usr/local/include/c++/12.1.0/complex:350:5: note: candidate: 'template<class _Tp> constexpr std::complex<_Tp> std::operator+(const _Tp&, const complex<_Tp>&)'
  350 |     operator+(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:350:5: note:   template argument deduction/substitution failed:
p325.cpp:54:19: note:   mismatched types 'const std::complex<_Tp>' and 'double'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
/usr/local/include/c++/12.1.0/complex:451:5: note: candidate: 'template<class _Tp> constexpr std::complex<_Tp> std::operator+(const complex<_Tp>&)'
  451 |     operator+(const complex<_Tp>& __x)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:451:5: note:   template argument deduction/substitution failed:
p325.cpp:54:19: note:   'Y' is not derived from 'const std::complex<_Tp>'
   54 |   int *a3 = Y() + 100.0;
      |                   ^~~~~
p325.cpp:31:10: note: candidate: 'String operator+(const String&, const String&)'
   31 |   String operator + (const String&, const String&);
      |          ^~~~~~~~
p325.cpp:31:22: note:   no known conversion for argument 1 from 'Y' to 'const String&'
   31 |   String operator + (const String&, const String&);
      |                      ^~~~~~~~~~~~~
p325.cpp:42:8: note: candidate: 'A operator+(const A&, const A&)'
   42 |      A operator+(const A&, const A&);
      |        ^~~~~~~~
p325.cpp:42:18: note:   no known conversion for argument 1 from 'Y' to 'const A&'
   42 |      A operator+(const A&, const A&);
      |                  ^~~~~~~~
p325.cpp:55:17: error: no match for 'operator+' (operand types are 'Y' and 'X')
   55 |   int *b3 = Y() + X();
      |             ~~~ ^ ~~~
      |             |     |
      |             Y     X
/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:
p325.cpp:55:21: note:   'X' is not derived from 'const std::reverse_iterator<_IteratorL>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'X' is not derived from 'const std::move_iterator<_IteratorL>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   mismatched types 'const _CharT*' and 'Y'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'X' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'Y' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'Y' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   mismatched types 'const _CharT*' and 'Y'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'X' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'Y' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/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:
p325.cpp:55:21: note:   'Y' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/complex:332:5: note: candidate: 'template<class _Tp> constexpr std::complex<_Tp> std::operator+(const complex<_Tp>&, const complex<_Tp>&)'
  332 |     operator+(const complex<_Tp>& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:332:5: note:   template argument deduction/substitution failed:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::complex<_Tp>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/complex:341:5: note: candidate: 'template<class _Tp> constexpr std::complex<_Tp> std::operator+(const complex<_Tp>&, const _Tp&)'
  341 |     operator+(const complex<_Tp>& __x, const _Tp& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:341:5: note:   template argument deduction/substitution failed:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::complex<_Tp>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/complex:350:5: note: candidate: 'template<class _Tp> constexpr std::complex<_Tp> std::operator+(const _Tp&, const complex<_Tp>&)'
  350 |     operator+(const _Tp& __x, const complex<_Tp>& __y)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:350:5: note:   template argument deduction/substitution failed:
p325.cpp:55:21: note:   'X' is not derived from 'const std::complex<_Tp>'
   55 |   int *b3 = Y() + X();
      |                     ^
/usr/local/include/c++/12.1.0/complex:451:5: note: candidate: 'template<class _Tp> constexpr std::complex<_Tp> std::operator+(const complex<_Tp>&)'
  451 |     operator+(const complex<_Tp>& __x)
      |     ^~~~~~~~
/usr/local/include/c++/12.1.0/complex:451:5: note:   template argument deduction/substitution failed:
p325.cpp:55:21: note:   'Y' is not derived from 'const std::complex<_Tp>'
   55 |   int *b3 = Y() + X();
      |                     ^
p325.cpp:31:10: note: candidate: 'String operator+(const String&, const String&)'
   31 |   String operator + (const String&, const String&);
      |          ^~~~~~~~
p325.cpp:31:22: note:   no known conversion for argument 1 from 'Y' to 'const String&'
   31 |   String operator + (const String&, const String&);
      |                      ^~~~~~~~~~~~~
p325.cpp:42:8: note: candidate: 'A operator+(const A&, const A&)'
   42 |      A operator+(const A&, const A&);
      |        ^~~~~~~~
p325.cpp:42:18: note:   no known conversion for argument 1 from 'Y' to 'const A&'
   42 |      A operator+(const A&, const A&);
      |                  ^~~~~~~~
p325.cpp:64:4: error: conflicting declaration 'A3 a3'
   64 | A3 a3;
      |    ^~
p325.cpp:54:8: note: previous declaration as 'int* a3'
   54 |   int *a3 = Y() + 100.0;
      |        ^~
p325.cpp: In member function 'void B3::f3()':
p325.cpp:66:13: error: no matching function for call to 'B3::operator+(int*&, int*&)'
   66 |   operator+ (a3,a3);
      |   ~~~~~~~~~~^~~~~~~
p325.cpp:61:8: note: candidate: 'void B3::operator+(B3)'
   61 |   void operator + (B3);
      |        ^~~~~~~~
p325.cpp:61:8: note:   candidate expects 1 argument, 2 provided
p325.cpp:67:6: error: invalid operands of types 'int*' and 'int*' to binary 'operator+'
   67 |   a3 + a3;
      |   ~~ ^ ~~
      |   |    |
      |   int* int*

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。

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)

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)

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