C++ Templates The Complete Guide(2nd Edition) (2) referror1.cpp

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目的

このコンパイル記録は、コンパイラおよび対応標準、コンパイラの版により、コンパイルエラーMessageの違いを記録し、どのエラーが出たら、どの版またはどの対応標準にすればエラーが少なくなるかを考察するための資料です。


成果

コンパイラの種類、対応標準の違いによってエラーの数が違う。同じエラーであってもMessageの表現が違う。Error Messageのネットで検索する際に役立つ。

C++ Templates The Complete Guide(2nd Edition)をclang++とg++でコンパイルしてみた

https://qiita.com/kaizen_nagoya/items/a7065ea839cb33793bdf


背景

C++のTemplate使いこなせてない。

The Complete Guide(2nd Edition)

http://www.tmplbook.com/code/code.html

コンパイルしながら勉強。


勉強の記録

https://researchmap.jp/joqzln3gi-1797580/#_1797580

だと, qiitaのようにコード表示機能がないためわかりにくい。

C++ Templates The Complete Guide(2nd Edition)をclang++とg++でコンパイルしてみた

https://qiita.com/kaizen_nagoya/items/a7065ea839cb33793bdf

コンパイルエラーになったものを

clang++, g++の -std=c++03, -std=c++2a

でコンパイルしながら一つづつ確認。


clang++

clang version 6.0.0 (tags/RELEASE_600/final)

Target: x86_64-apple-darwin17.5.0

Thread model: posix

InstalledDir: /usr/local/opt/llvm/bin


g++

g++ (Homebrew GCC 8.1.0) 8.1.0

Copyright (C) 2018 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.


basics/errornovel1.cpp

template<typename T, T Z = T{}>

class RefMem {
private:
T zero;
public:
RefMem() : zero{Z} {
}
};

int null = 0;

int main()
{
RefMem<int> rm1, rm2;
rm1 = rm2; // OK

RefMem<int&> rm3; // ERROR: invalid default value for N
RefMem<int&, 0> rm4; // ERROR: invalid default value for N

extern int null;
RefMem<int&,null> rm5, rm6;
rm5 = rm6; // ERROR: operator= is deleted due to reference member
}



cpla.sh

$ ../cpla.sh referror1

../cpla.sh: line 1: spla.sh: command not found
$ clang++ referror1.cpp -std=c++03 -Wall
referror1.cpp:1:29: error: expected '(' for function-style cast or type
construction
template<typename T, T Z = T{}>
~^
referror1.cpp:6:24: error: expected member name or ';' after declaration
specifiers
RefMem() : zero{Z} {
^
referror1.cpp:6:20: error: expected '('
RefMem() : zero{Z} {
^
referror1.cpp:6:22: error: expected ';' after expression
RefMem() : zero{Z} {
^
;
referror1.cpp:14:5: error: too few template arguments for class template
'RefMem'
RefMem<int> rm1, rm2;
^
referror1.cpp:2:7: note: template is declared here
class RefMem {
^
referror1.cpp:15:11: error: use of undeclared identifier 'rm2'
rm1 = rm2; // OK
^
referror1.cpp:17:5: error: too few template arguments for class template
'RefMem'
RefMem<int&> rm3; // ERROR: invalid default value for N
^
referror1.cpp:2:7: note: template is declared here
class RefMem {
^
referror1.cpp:18:18: error: non-type template argument does not refer to any
declaration
RefMem<int&, 0> rm4; // ERROR: invalid default value for N
^
referror1.cpp:1:24: note: template parameter is declared here
template<typename T, T Z = T{}>
^
referror1.cpp:2:7: error: implicit default constructor for
'RefMem<int &, &null>' must explicitly initialize the reference member
'zero'
class RefMem {
^
referror1.cpp:21:28: note: in implicit default constructor for
'RefMem<int &, &null>' first required here
RefMem<int&,null> rm5, rm6;
^
referror1.cpp:4:7: note: declared here
T zero;
^
9 errors generated.
$ clang++ referror1.cpp -std=c++2a -Wall
referror1.cpp:1:28: error: non-const lvalue reference to type 'int' cannot bind
to an initializer list temporary
template<typename T, T Z = T{}>
^~~
referror1.cpp:17:5: note: in instantiation of default argument for
'RefMem<int &>' required here
RefMem<int&> rm3; // ERROR: invalid default value for N
^~~~~~~~~~~~
referror1.cpp:18:18: error: value of type 'int' is not implicitly convertible to
'int &'
RefMem<int&, 0> rm4; // ERROR: invalid default value for N
^
referror1.cpp:22:9: error: object of type 'RefMem<int &, &null>' cannot be
assigned because its copy assignment operator is implicitly deleted
rm5 = rm6; // ERROR: operator= is deleted due to referen...
^
referror1.cpp:4:7: note: copy assignment operator of 'RefMem<int &, &null>' is
implicitly deleted because field 'zero' is of reference type 'int &'
T zero;
^
3 errors generated.
\r
$ g++-8 referror1.cpp -std=c++03 -Wall
referror1.cpp:1:29: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11
template<typename T, T Z = T{}>
^
referror1.cpp: In constructor 'RefMem<T, Z>::RefMem()':
referror1.cpp:6:20: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11
RefMem() : zero{Z} {
^
referror1.cpp: In function 'int main()':
referror1.cpp:17:16: error: invalid cast of an rvalue expression of type 'int' to type 'int&'
RefMem<int&> rm3; // ERROR: invalid default value for N
^
referror1.cpp:17:16: error: template argument 2 is invalid
referror1.cpp:18:19: error: '0' is not a valid template argument for type 'int&' because it is not an lvalue
RefMem<int&, 0> rm4; // ERROR: invalid default value for N
^
referror1.cpp: In member function 'RefMem<int&, null>& RefMem<int&, null>::operator=(const RefMem<int&, null>&)':
referror1.cpp:2:7: error: non-static reference member 'int& RefMem<int&, null>::zero', can't use default assignment operator
class RefMem {
^~~~~~
referror1.cpp: In function 'int main()':
referror1.cpp:22:11: note: synthesized method 'RefMem<int&, null>& RefMem<int&, null>::operator=(const RefMem<int&, null>&)' first required here
rm5 = rm6; // ERROR: operator= is deleted due to reference member
^~~
referror1.cpp:17:18: warning: unused variable 'rm3' [-Wunused-variable]
RefMem<int&> rm3; // ERROR: invalid default value for N
^~~
referror1.cpp:18:21: warning: unused variable 'rm4' [-Wunused-variable]
RefMem<int&, 0> rm4; // ERROR: invalid default value for N
^~~
referror1.cpp: In instantiation of 'RefMem<T, Z>::RefMem() [with T = int&; T Z = null]':
referror1.cpp:21:23: required from here
referror1.cpp:6:22: warning: extended initializer lists only available with -std=c++11 or -std=gnu++11
RefMem() : zero{Z} {
^
\r
$ g++-8 referror1.cpp -std=c++2a -Wall
referror1.cpp: In function 'int main()':
referror1.cpp:17:16: error: invalid cast of an rvalue expression of type 'int' to type 'int&'
RefMem<int&> rm3; // ERROR: invalid default value for N
^
referror1.cpp:17:16: error: template argument 2 is invalid
referror1.cpp:18:19: error: initializing 'int&' with 'int' in converted constant expression does not bind directly
RefMem<int&, 0> rm4; // ERROR: invalid default value for N
^
referror1.cpp:18:19: error: could not convert template argument '0' from 'int' to 'int&'
referror1.cpp:22:11: error: use of deleted function 'RefMem<int&, null>& RefMem<int&, null>::operator=(const RefMem<int&, null>&)'
rm5 = rm6; // ERROR: operator= is deleted due to reference member
^~~
referror1.cpp:2:7: note: 'RefMem<int&, null>& RefMem<int&, null>::operator=(const RefMem<int&, null>&)' is implicitly deleted because the default definition would be ill-formed:
class RefMem {
^~~~~~
referror1.cpp:2:7: error: non-static reference member 'int& RefMem<int&, null>::zero', can't use default assignment operator
referror1.cpp:17:18: warning: unused variable 'rm3' [-Wunused-variable]
RefMem<int&> rm3; // ERROR: invalid default value for N
^~~
referror1.cpp:18:21: warning: unused variable 'rm4' [-Wunused-variable]
RefMem<int&, 0> rm4; // ERROR: invalid default value for N
^~~


まとめ

cpp
clang++

g++

-std=c++03
-std=c++2a
-std=c++03
-std=c++2a

referror1
9
3
4
6


検討事項(agenda)

1)コンパイルエラーをなくす修正方法

clang++ -std=c++2aは想定個数と同じ。

2)役に立つまたは意味のあるその他の出力


参考資料(reference)


プログラミング言語教育のXYZ

https://qiita.com/kaizen_nagoya/items/1950c5810fb5c0b07be4

プログラミング言語教育のXYZ(youtube)

https://www.youtube.com/watch?v=He1_tg4px-w&t=486s


C++N4741 2018

Working Draft, Standard for Programming Language C++

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/n4741.pdf

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

https://qiita.com/kaizen_nagoya/items/3294c014044550896010


C++N4606 2016

Working Draft, Standard for Programming Language C++

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/n4606.pdf

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

Working Draft 2016, ISO/IEC 14882(1)

https://qiita.com/kaizen_nagoya/items/df5d62c35bd6ed1c3d43/


 CEDD(Compile Error Driven Design)

初めての CEDD(Compile Error Driven Design) 8回直してコンパイル。

https://qiita.com/kaizen_nagoya/items/9494236aa1753f3fd1e1

コンパイルエラーを記録するとよい理由7つ

https://qiita.com/kaizen_nagoya/items/85c0e92b206883140e89

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

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

[C][C++]の国際規格案の例題をコンパイルするときの課題7つ。

https://qiita.com/kaizen_nagoya/items/5f4b155030259497c4de

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


文書履歴(document history)

ver. 0.10 初稿 20180515 コンパイルエラーが取れていない。