C++(91) Templates The Complete Guide(2nd Edition) (3)basics/referror2.cpp

C言語を習得する３つの方法
https://qiita.com/kaizen_nagoya/items/84cab0888c193bba429b

C言語(C++)が必要な人と必要ない人
https://qiita.com/kaizen_nagoya/items/2afe9e846b55b24cb6f1
# 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。

# 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.

```c++:basics/projectioniterator.cpp
#include <vector>
#include <iostream>

template<typename T, int& SZ>     // Note: size is reference
class Arr {
private:
  std::vector<T> elems;
public:
  Arr() : elems(SZ) {           // use current SZ as initial vector size
  }
  void print() const {
    for (int i=0; i<SZ; ++i) {  // loop over SZ elements
      std::cout << elems[i] << ' ';
    }
  }
};

int size = 10;

int main()
{
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std::vector<>

  Arr<int,size> x;  // initializes internal vector with 10 elements
  x.print();        // OK
  size += 100;      // OOPS: modifies SZ in Arr<>
  x.print();        // run-time ERROR: invalid memory access: loops over 120 elements
}
```

```shell-session:cpla.sh
$ ../cpla.sh referror2
../cpla.sh: line 1: spla.sh: command not found
$ clang++ referror2.cpp -std=c++03 -Wall
In file included from referror2.cpp:1:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:266:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/__bit_reference:15:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/algorithm:643:
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1770:16: error: 'pointer'
      declared as a pointer to a reference of type 'int &'
    typedef _Tp*              pointer;
               ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1515:22: note: in
      instantiation of template class 'std::__1::allocator<int &>' requested
      here
    typedef typename allocator_type::value_type value_type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:325:22: note: in
      instantiation of template class
      'std::__1::allocator_traits<std::__1::allocator<int &> >' requested here
    typedef typename __alloc_traits::size_type       size_type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:448:15: note: in
      instantiation of template class 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >' requested here
    : private __vector_base<_Tp, _Allocator>
              ^
referror2.cpp:7:20: note: in instantiation of template class
      'std::__1::vector<int &, std::__1::allocator<int &> >' requested here
    std::vector<T> elems;
                   ^
referror2.cpp:22:18: note: in instantiation of template class
      'Arr<int &, &size>' requested here
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std:...
                 ^
In file included from referror2.cpp:1:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:266:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/__bit_reference:15:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/algorithm:643:
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1771:22: error: 
      'const_pointer' declared as a pointer to a reference of type 'int &'
    typedef const _Tp*        const_pointer;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1785:45: error: multiple
      overloads of 'address' instantiate to the same signature
      'std::__1::allocator<int &>::const_pointer (std::__1::allocator<int
      &>::const_reference) const throw()' (aka 'int (int &) const throw()')
    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x...
                                            ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1783:39: note: previous
      declaration is here
    _LIBCPP_INLINE_VISIBILITY pointer address(reference __x) const _NOEXCEPT
                                      ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:950:22: error: implicit
      instantiation of undefined template
      'std::__1::__pointer_traits_element_type<int, false>'
    typedef typename __pointer_traits_element_type<pointer>::type    ele...
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1074:22: note: in
      instantiation of template class 'std::__1::pointer_traits<int>' requested
      here
    typedef typename pointer_traits<_Ptr>::template rebind<void>::other type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1519:22: note: in
      instantiation of template class 'std::__1::__void_pointer<int,
      std::__1::allocator<int &>, false>' requested here
    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:325:22: note: in
      instantiation of template class
      'std::__1::allocator_traits<std::__1::allocator<int &> >' requested here
    typedef typename __alloc_traits::size_type       size_type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:448:15: note: in
      instantiation of template class 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >' requested here
    : private __vector_base<_Tp, _Allocator>
              ^
referror2.cpp:7:20: note: in instantiation of template class
      'std::__1::vector<int &, std::__1::allocator<int &> >' requested here
    std::vector<T> elems;
                   ^
referror2.cpp:22:18: note: in instantiation of template class
      'Arr<int &, &size>' requested here
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std:...
                 ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:740:8: note: template is
      declared here
struct __pointer_traits_element_type;
       ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1074:53: error: 'rebind'
      following the 'template' keyword does not refer to a template
    typedef typename pointer_traits<_Ptr>::template rebind<void>::other type;
                                                    ^~~~~~
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1519:22: note: in
      instantiation of template class 'std::__1::__void_pointer<int,
      std::__1::allocator<int &>, false>' requested here
    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:325:22: note: in
      instantiation of template class
      'std::__1::allocator_traits<std::__1::allocator<int &> >' requested here
    typedef typename __alloc_traits::size_type       size_type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:448:15: note: in
      instantiation of template class 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >' requested here
    : private __vector_base<_Tp, _Allocator>
              ^
referror2.cpp:7:20: note: in instantiation of template class
      'std::__1::vector<int &, std::__1::allocator<int &> >' requested here
    std::vector<T> elems;
                   ^
referror2.cpp:22:18: note: in instantiation of template class
      'Arr<int &, &size>' requested here
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std:...
                 ^
In file included from referror2.cpp:1:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:266:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/__bit_reference:15:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/algorithm:643:
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:852:22: error: type 'int'
      cannot be used prior to '::' because it has no members
    typedef typename _Tp::template rebind<_Up>::other type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:957:27: note: in
      instantiation of template class 'std::__1::__pointer_traits_rebind<int,
      const void, false>' requested here
        {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
                          ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1097:44: note: in
      instantiation of template class
      'std::__1::pointer_traits<int>::rebind<const void>' requested here
    typedef typename pointer_traits<_Ptr>::template rebind<const void>::...
                                           ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1520:22: note: in
      instantiation of template class 'std::__1::__const_void_pointer<int,
      std::__1::allocator<int &>, false>' requested here
    typedef typename __const_void_pointer<pointer, allocator_type>::typ...
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:325:22: note: in
      instantiation of template class
      'std::__1::allocator_traits<std::__1::allocator<int &> >' requested here
    typedef typename __alloc_traits::size_type       size_type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:448:15: note: in
      instantiation of template class 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >' requested here
    : private __vector_base<_Tp, _Allocator>
              ^
referror2.cpp:7:20: note: in instantiation of template class
      'std::__1::vector<int &, std::__1::allocator<int &> >' requested here
    std::vector<T> elems;
                   ^
referror2.cpp:22:18: note: in instantiation of template class
      'Arr<int &, &size>' requested here
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std:...
                 ^
In file included from referror2.cpp:1:
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:457:30: error: 
      '__alloc_traits' is a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::__alloc_traits          __alloc_traits;
                             ^
referror2.cpp:7:20: note: in instantiation of template class
      'std::__1::vector<int &, std::__1::allocator<int &> >' requested here
    std::vector<T> elems;
                   ^
referror2.cpp:22:18: note: in instantiation of template class
      'Arr<int &, &size>' requested here
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std:...
                 ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:322:54: note: declared
      protected here
    typedef allocator_traits<allocator_type>         __alloc_traits;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:458:30: error: 'reference' is
      a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::reference               reference;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:323:54: note: declared
      protected here
    typedef value_type&                              reference;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:459:30: error: 
      'const_reference' is a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::const_reference         const_reference;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:324:54: note: declared
      protected here
    typedef const value_type&                        const_reference;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:460:30: error: 'size_type' is
      a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::size_type               size_type;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:325:54: note: declared
      protected here
    typedef typename __alloc_traits::size_type       size_type;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:461:30: error: 
      'difference_type' is a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::difference_type         difference_type;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:326:54: note: declared
      protected here
    typedef typename __alloc_traits::difference_type difference_type;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:462:30: error: 'pointer' is a
      protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::pointer                 pointer;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:327:54: note: declared
      protected here
    typedef typename __alloc_traits::pointer         pointer;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:463:30: error: 
      'const_pointer' is a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::const_pointer           const_pointer;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:328:54: note: declared
      protected here
    typedef typename __alloc_traits::const_pointer   const_pointer;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:671:15: error: 'data'
      declared as a pointer to a reference of type 'std::__1::vector<int &,
      std::__1::allocator<int &> >::value_type' (aka 'int &')
    value_type*       data() _NOEXCEPT
              ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:674:21: error: 'data'
      declared as a pointer to a reference of type 'std::__1::vector<int &,
      std::__1::allocator<int &> >::value_type' (aka 'int &')
    const value_type* data() const _NOEXCEPT
                    ^
15 errors generated.
$ clang++ referror2.cpp -std=c++2a -Wall
In file included from referror2.cpp:1:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:266:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/__bit_reference:15:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/algorithm:643:
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1770:16: error: 'pointer'
      declared as a pointer to a reference of type 'int &'
    typedef _Tp*              pointer;
               ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1515:22: note: in
      instantiation of template class 'std::__1::allocator<int &>' requested
      here
    typedef typename allocator_type::value_type value_type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:325:22: note: in
      instantiation of template class
      'std::__1::allocator_traits<std::__1::allocator<int &> >' requested here
    typedef typename __alloc_traits::size_type       size_type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:448:15: note: in
      instantiation of template class 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >' requested here
    : private __vector_base<_Tp, _Allocator>
              ^
referror2.cpp:7:20: note: in instantiation of template class
      'std::__1::vector<int &, std::__1::allocator<int &> >' requested here
    std::vector<T> elems;
                   ^
referror2.cpp:22:18: note: in instantiation of template class
      'Arr<int &, &size>' requested here
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std:...
                 ^
In file included from referror2.cpp:1:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:266:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/__bit_reference:15:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/algorithm:643:
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1771:22: error: 
      'const_pointer' declared as a pointer to a reference of type 'int &'
    typedef const _Tp*        const_pointer;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1785:45: error: multiple
      overloads of 'address' instantiate to the same signature
      'std::__1::allocator<int &>::const_pointer (std::__1::allocator<int
      &>::const_reference) const noexcept' (aka 'int (int &) const noexcept')
    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x...
                                            ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1783:39: note: previous
      declaration is here
    _LIBCPP_INLINE_VISIBILITY pointer address(reference __x) const _NOEXCEPT
                                      ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:950:22: error: implicit
      instantiation of undefined template
      'std::__1::__pointer_traits_element_type<int, false>'
    typedef typename __pointer_traits_element_type<pointer>::type    ele...
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1072:22: note: in
      instantiation of template class 'std::__1::pointer_traits<int>' requested
      here
    typedef typename pointer_traits<_Ptr>::template rebind<void> type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1519:22: note: in
      instantiation of template class 'std::__1::__void_pointer<int,
      std::__1::allocator<int &>, false>' requested here
    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:325:22: note: in
      instantiation of template class
      'std::__1::allocator_traits<std::__1::allocator<int &> >' requested here
    typedef typename __alloc_traits::size_type       size_type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:448:15: note: in
      instantiation of template class 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >' requested here
    : private __vector_base<_Tp, _Allocator>
              ^
referror2.cpp:7:20: note: in instantiation of template class
      'std::__1::vector<int &, std::__1::allocator<int &> >' requested here
    std::vector<T> elems;
                   ^
referror2.cpp:22:18: note: in instantiation of template class
      'Arr<int &, &size>' requested here
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std:...
                 ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:740:8: note: template is
      declared here
struct __pointer_traits_element_type;
       ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1072:53: error: 'rebind'
      following the 'template' keyword does not refer to a template
    typedef typename pointer_traits<_Ptr>::template rebind<void> type;
                                                    ^~~~~~
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1519:22: note: in
      instantiation of template class 'std::__1::__void_pointer<int,
      std::__1::allocator<int &>, false>' requested here
    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:325:22: note: in
      instantiation of template class
      'std::__1::allocator_traits<std::__1::allocator<int &> >' requested here
    typedef typename __alloc_traits::size_type       size_type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:448:15: note: in
      instantiation of template class 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >' requested here
    : private __vector_base<_Tp, _Allocator>
              ^
referror2.cpp:7:20: note: in instantiation of template class
      'std::__1::vector<int &, std::__1::allocator<int &> >' requested here
    std::vector<T> elems;
                   ^
referror2.cpp:22:18: note: in instantiation of template class
      'Arr<int &, &size>' requested here
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std:...
                 ^
In file included from referror2.cpp:1:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:266:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/__bit_reference:15:
In file included from /usr/local/Cellar/llvm/6.0.0/include/c++/v1/algorithm:643:
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:850:22: error: type 'int'
      cannot be used prior to '::' because it has no members
    typedef typename _Tp::template rebind<_Up> type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:954:26: note: in
      instantiation of template class 'std::__1::__pointer_traits_rebind<int,
      const void, false>' requested here
    template <class _Up> using rebind = typename __pointer_traits_rebind...
                         ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1095:53: note: in
      instantiation of template type alias 'rebind' requested here
    typedef typename pointer_traits<_Ptr>::template rebind<const void> type;
                                                    ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/memory:1520:22: note: in
      instantiation of template class 'std::__1::__const_void_pointer<int,
      std::__1::allocator<int &>, false>' requested here
    typedef typename __const_void_pointer<pointer, allocator_type>::typ...
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:325:22: note: in
      instantiation of template class
      'std::__1::allocator_traits<std::__1::allocator<int &> >' requested here
    typedef typename __alloc_traits::size_type       size_type;
                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:448:15: note: in
      instantiation of template class 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >' requested here
    : private __vector_base<_Tp, _Allocator>
              ^
referror2.cpp:7:20: note: in instantiation of template class
      'std::__1::vector<int &, std::__1::allocator<int &> >' requested here
    std::vector<T> elems;
                   ^
referror2.cpp:22:18: note: in instantiation of template class
      'Arr<int &, &size>' requested here
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std:...
                 ^
In file included from referror2.cpp:1:
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:457:30: error: 
      '__alloc_traits' is a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::__alloc_traits          __alloc_traits;
                             ^
referror2.cpp:7:20: note: in instantiation of template class
      'std::__1::vector<int &, std::__1::allocator<int &> >' requested here
    std::vector<T> elems;
                   ^
referror2.cpp:22:18: note: in instantiation of template class
      'Arr<int &, &size>' requested here
  Arr<int&,size> y; // compile-time ERROR deep in the code of class std:...
                 ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:322:54: note: declared
      protected here
    typedef allocator_traits<allocator_type>         __alloc_traits;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:458:30: error: 'reference' is
      a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::reference               reference;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:323:54: note: declared
      protected here
    typedef value_type&                              reference;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:459:30: error: 
      'const_reference' is a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::const_reference         const_reference;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:324:54: note: declared
      protected here
    typedef const value_type&                        const_reference;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:460:30: error: 'size_type' is
      a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::size_type               size_type;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:325:54: note: declared
      protected here
    typedef typename __alloc_traits::size_type       size_type;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:461:30: error: 
      'difference_type' is a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::difference_type         difference_type;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:326:54: note: declared
      protected here
    typedef typename __alloc_traits::difference_type difference_type;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:462:30: error: 'pointer' is a
      protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::pointer                 pointer;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:327:54: note: declared
      protected here
    typedef typename __alloc_traits::pointer         pointer;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:463:30: error: 
      'const_pointer' is a protected member of 'std::__1::__vector_base<int &,
      std::__1::allocator<int &> >'
    typedef typename __base::const_pointer           const_pointer;
                             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:328:54: note: declared
      protected here
    typedef typename __alloc_traits::const_pointer   const_pointer;
                                                     ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:671:15: error: 'data'
      declared as a pointer to a reference of type 'std::__1::vector<int &,
      std::__1::allocator<int &> >::value_type' (aka 'int &')
    value_type*       data() _NOEXCEPT
              ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:674:21: error: 'data'
      declared as a pointer to a reference of type 'std::__1::vector<int &,
      std::__1::allocator<int &> >::value_type' (aka 'int &')
    const value_type* data() const _NOEXCEPT
                    ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:691:36: error: multiple
      overloads of 'push_back' instantiate to the same signature 'void
      (std::__1::vector<int &, std::__1::allocator<int &> >::value_type &)'
    _LIBCPP_INLINE_VISIBILITY void push_back(value_type&& __x);
                                   ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:688:36: note: previous
      declaration is here
    _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
                                   ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:708:14: error: multiple
      overloads of 'insert' instantiate to the same signature
      'std::__1::vector<int &, std::__1::allocator<int &> >::iterator
      (std::__1::vector<int &, std::__1::allocator<int &> >::const_iterator,
      std::__1::vector<int &, std::__1::allocator<int &> >::value_type &)' (aka
      '__wrap_iter<int> (__wrap_iter<int>, int &)')
    iterator insert(const_iterator __position, value_type&& __x);
             ^
/usr/local/Cellar/llvm/6.0.0/include/c++/v1/vector:705:14: note: previous
      declaration is here
    iterator insert(const_iterator __position, const_reference __x);
             ^
17 errors generated.
\r
$ g++-8 referror2.cpp -std=c++03  -Wall
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/x86_64-apple-darwin17.5.0/bits/c++allocator.h:33,
                 from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h:46,
                 from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:61,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/new_allocator.h: In instantiation of 'class __gnu_cxx::new_allocator<int&>':
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h:108:11:   required from 'class std::allocator<int&>'
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:84:21:   required from 'struct std::_Vector_base<int&, std::allocator<int&> >'
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:339:11:   required from 'class std::vector<int&, std::allocator<int&> >'
referror2.cpp:7:20:   required from 'class Arr<int&, size>'
referror2.cpp:22:18:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/new_allocator.h:63:26: error:forming pointer to reference type 'int&'
       typedef _Tp*       pointer;
                          ^~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/new_allocator.h:64:26: error:forming pointer to reference type 'int&'
       typedef const _Tp* const_pointer;
                          ^~~~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/new_allocator.h:65:26: error:forming reference to reference type 'int&'
       typedef _Tp&       reference;
                          ^~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/new_allocator.h:66:26: error:forming reference to reference type 'int&'
       typedef const _Tp& const_reference;
                          ^~~~~~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/new_allocator.h:145:7: error:forming reference to reference type 'int&'
       construct(pointer __p, const _Tp& __val)
       ^~~~~~~~~
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:61,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h: In instantiation of 'class std::allocator<int&>':
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:84:21:   required from 'struct std::_Vector_base<int&, std::allocator<int&> >'
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:339:11:   required from 'class std::vector<int&, std::allocator<int&> >'
referror2.cpp:7:20:   required from 'class Arr<int&, size>'
referror2.cpp:22:18:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h:113:26: error: forming pointer to reference type 'int&'
       typedef _Tp*       pointer;
                          ^~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h:114:26: error: forming pointer to reference type 'int&'
       typedef const _Tp* const_pointer;
                          ^~~~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h:115:26: error: forming reference to reference type 'int&'
       typedef _Tp&       reference;
                          ^~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h:116:26: error: forming reference to reference type 'int&'
       typedef const _Tp& const_reference;
                          ^~~~~~~~~~~~~~~
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:64,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h: In instantiation of 'class std::vector<int&, std::allocator<int&> >':
referror2.cpp:7:20:   required from 'class Arr<int&, size>'
referror2.cpp:22:18:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:379:20: error: no members matching 'std::vector<int&, std::allocator<int&> >::_Base {aka std::_Vector_base<int&, std::allocator<int&> >}::_M_allocate' in 'std::vector<int&, std::allocator<int&> >::_Base' {aka 'struct std::_Vector_base<int&, std::allocator<int&> >'}
       using _Base::_M_allocate;
                    ^~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:380:20: error: no members matching 'std::vector<int&, std::allocator<int&> >::_Base {aka std::_Vector_base<int&, std::allocator<int&> >}::_M_deallocate' in 'std::vector<int&, std::allocator<int&> >::_Base' {aka 'struct std::_Vector_base<int&, std::allocator<int&> >'}
       using _Base::_M_deallocate;
                    ^~~~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:441:7: error: forming reference to reference type 'std::vector<int&, std::allocator<int&> >::value_type' {aka 'int&'}
       vector(size_type __n, const value_type& __value = value_type(),
       ^~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:636:7: error: forming reference to reference type 'std::vector<int&, std::allocator<int&> >::value_type' {aka 'int&'}
       assign(size_type __n, const value_type& __val)
       ^~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1055:7: error: forming pointer to reference type 'int&'
       data() _GLIBCXX_NOEXCEPT
       ^~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1059:7: error: forming pointer to reference type 'int&'
       data() const _GLIBCXX_NOEXCEPT
       ^~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1074:7: error: forming reference to reference type 'std::vector<int&, std::allocator<int&> >::value_type' {aka 'int&'}
       push_back(const value_type& __x)
       ^~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1243:7: error: forming reference to reference type 'std::vector<int&, std::allocator<int&> >::value_type' {aka 'int&'}
       insert(iterator __position, size_type __n, const value_type& __x)
       ^~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1472:7: error: forming reference to reference type 'std::vector<int&, std::allocator<int&> >::value_type' {aka 'int&'}
       _M_fill_initialize(size_type __n, const value_type& __value)
       ^~~~~~~~~~~~~~~~~~
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:69,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/vector.tcc:245:5: error: forming reference to reference type 'std::vector<int&, std::allocator<int&> >::value_type' {aka 'int&'}
     vector<_Tp, _Alloc>::
     ^~~~~~~~~~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/vector.tcc:478:5: error: forming reference to reference type 'std::vector<int&, std::allocator<int&> >::value_type' {aka 'int&'}
     vector<_Tp, _Alloc>::
     ^~~~~~~~~~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/vector.tcc:387:5: error: forming reference to reference type 'int&'
     vector<_Tp, _Alloc>::
     ^~~~~~~~~~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/vector.tcc:418:5: error: forming reference to reference type 'int&'
     vector<_Tp, _Alloc>::
     ^~~~~~~~~~~~~~~~~~~
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:64,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1716:2: error: forming pointer to reference type 'std::vector<int&, std::allocator<int&> >::value_type' {aka 'int&'}
  _M_data_ptr(_Ptr __ptr)
  ^~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1721:2: error: forming pointer to reference type 'std::vector<int&, std::allocator<int&> >::value_type' {aka 'int&'}
  _M_data_ptr(_Ptr __ptr) const
  ^~~~~~~~~~~
referror2.cpp: In instantiation of 'Arr<T, SZ>::Arr() [with T = int&; int& SZ = size]':
referror2.cpp:22:18:   required from here
referror2.cpp:9:21: error: no matching function for call to 'std::vector<int&, std::allocator<int&> >::vector(int&)'
     Arr() : elems(SZ) {           // use current SZ as initial vector size
                     ^
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:64,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:549:2: note: candidate: 'template<class _InputIterator> std::vector<_Tp, _Alloc>::vector(_InputIterator, _InputIterator, const allocator_type&)'
  vector(_InputIterator __first, _InputIterator __last,
  ^~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:549:2: note:   template argument deduction/substitution failed:
referror2.cpp:9:21: note:   candidate expects 3 arguments, 1 provided
     Arr() : elems(SZ) {           // use current SZ as initial vector size
                     ^
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:64,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:458:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const std::vector<_Tp, _Alloc>&) [with _Tp = int&; _Alloc = std::allocator<int&>]'
       vector(const vector& __x)
       ^~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:458:7: note:   no known conversion for argument 1 from 'int' to 'const std::vector<int&, std::allocator<int&> >&'
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:402:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector(const allocator_type&) [with _Tp = int&; _Alloc = std::allocator<int&>; std::vector<_Tp, _Alloc>::allocator_type = std::allocator<int&>]'
       vector(const allocator_type& __a) _GLIBCXX_NOEXCEPT
       ^~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:402:7: note:   no known conversion for argument 1 from 'int' to 'const allocator_type&' {aka 'const std::allocator<int&>&'}
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:391:7: note: candidate: 'std::vector<_Tp, _Alloc>::vector() [with _Tp = int&; _Alloc = std::allocator<int&>]'
       vector()
       ^~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:391:7: note:   candidate expects 0 arguments, 1 provided
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h: In instantiation of 'std::vector<_Tp, _Alloc>::~vector() [with _Tp = int&; _Alloc = std::allocator<int&>]':
referror2.cpp:5:7:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:567:30: error: struct std::_Vector_base<int&, std::allocator<int&> >::_Vector_impl' has no member named '_M_start'
  std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
                ~~~~~~~~~~~~~~^~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:567:54: error: struct std::_Vector_base<int&, std::allocator<int&> >::_Vector_impl' has no member named '_M_finish'
  std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
                                        ~~~~~~~~~~~~~~^~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h: In instantiation of 'std::_Vector_base<_Tp, _Alloc>::~_Vector_base() [with _Tp = int&; _Alloc = std::allocator<int&>]':
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:570:7:   required from 'std::vector<_Tp, _Alloc>::~vector() [with _Tp = int&; _Alloc = std::allocator<int&>]'
referror2.cpp:5:7:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:285:24: error: struct std::_Vector_base<int&, std::allocator<int&> >::_Vector_impl' has no member named '_M_start'
  _M_deallocate(_M_impl._M_start,
                ~~~~~~~~^~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:286:17: error: struct std::_Vector_base<int&, std::allocator<int&> >::_Vector_impl' has no member named '_M_end_of_storage'
         _M_impl._M_end_of_storage - _M_impl._M_start);
         ~~~~~~~~^~~~~~~~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:286:45: error: struct std::_Vector_base<int&, std::allocator<int&> >::_Vector_impl' has no member named '_M_start'
         _M_impl._M_end_of_storage - _M_impl._M_start);
                                     ~~~~~~~~^~~~~~~~
\r
$ g++-8 referror2.cpp -std=c++2a  -Wall
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/x86_64-apple-darwin17.5.0/bits/c++allocator.h:33,
                 from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h:46,
                 from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:61,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/new_allocator.h: In instantiation of 'class __gnu_cxx::new_allocator<int&>':
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h:108:11:   required from 'class std::allocator<int&>'
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:84:21:   required from 'struct std::_Vector_base<int&, std::allocator<int&> >'
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:339:11:   required from 'class std::vector<int&, std::allocator<int&> >'
referror2.cpp:7:20:   required from 'class Arr<int&, size>'
referror2.cpp:22:18:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/new_allocator.h:63:26: error:forming pointer to reference type 'int&'
       typedef _Tp*       pointer;
                          ^~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/new_allocator.h:64:26: error:forming pointer to reference type 'int&'
       typedef const _Tp* const_pointer;
                          ^~~~~~~~~~~~~
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:61,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h: In instantiation of 'class std::allocator<int&>':
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:84:21:   required from 'struct std::_Vector_base<int&, std::allocator<int&> >'
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:339:11:   required from 'class std::vector<int&, std::allocator<int&> >'
referror2.cpp:7:20:   required from 'class Arr<int&, size>'
referror2.cpp:22:18:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h:113:26: error: forming pointer to reference type 'int&'
       typedef _Tp*       pointer;
                          ^~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/allocator.h:114:26: error: forming pointer to reference type 'int&'
       typedef const _Tp* const_pointer;
                          ^~~~~~~~~~~~~
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/alloc_traits.h:36,
                 from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_construct.h:61,
                 from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:62,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/alloc_traits.h: In instantiation of 'struct std::allocator_traits<std::allocator<int&> >':
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/alloc_traits.h:50:10:   required from 'struct __gnu_cxx::__alloc_traits<std::allocator<int&>, int&>'
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:84:21:   required from 'struct std::_Vector_base<int&, std::allocator<int&> >'
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:339:11:   required from 'class std::vector<int&, std::allocator<int&> >'
referror2.cpp:7:20:   required from 'class Arr<int&, size>'
referror2.cpp:22:18:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/alloc_traits.h:392:27: error: forming pointer to reference type 'int&'
       using pointer = _Tp*;
                           ^
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/alloc_traits.h:395:39: error: forming pointer to reference type 'int&'
       using const_pointer = const _Tp*;
                                       ^
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_construct.h:61,
                 from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:62,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/alloc_traits.h: In instantiation of 'struct __gnu_cxx::__alloc_traits<std::allocator<int&>, int&>':
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:84:21:   required from 'struct std::_Vector_base<int&, std::allocator<int&> >'
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:339:11:   required from 'class std::vector<int&, std::allocator<int&> >'
referror2.cpp:7:20:   required from 'class Arr<int&, size>'
referror2.cpp:22:18:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/alloc_traits.h:66:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<int&>, int&>::_Base_type {aka std::allocator_traits<std::allocator<int&> >}::allocate' in '__gnu_cxx::__alloc_traits<std::allocator<int&>, int&>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<int&> >'}
     using _Base_type::allocate;
                       ^~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/ext/alloc_traits.h:67:23: error: no members matching '__gnu_cxx::__alloc_traits<std::allocator<int&>, int&>::_Base_type {aka std::allocator_traits<std::allocator<int&> >}::deallocate' in '__gnu_cxx::__alloc_traits<std::allocator<int&>, int&>::_Base_type' {aka 'struct std::allocator_traits<std::allocator<int&> >'}
     using _Base_type::deallocate;
                       ^~~~~~~~~~
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:64,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h: In instantiation of 'class std::vector<int&, std::allocator<int&> >':
referror2.cpp:7:20:   required from 'class Arr<int&, size>'
referror2.cpp:22:18:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:379:20: error: no members matching 'std::vector<int&, std::allocator<int&> >::_Base {aka std::_Vector_base<int&, std::allocator<int&> >}::_M_allocate' in 'std::vector<int&, std::allocator<int&> >::_Base' {aka 'struct std::_Vector_base<int&, std::allocator<int&> >'}
       using _Base::_M_allocate;
                    ^~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:380:20: error: no members matching 'std::vector<int&, std::allocator<int&> >::_Base {aka std::_Vector_base<int&, std::allocator<int&> >}::_M_deallocate' in 'std::vector<int&, std::allocator<int&> >::_Base' {aka 'struct std::_Vector_base<int&, std::allocator<int&> >'}
       using _Base::_M_deallocate;
                    ^~~~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1055:7: error: forming pointer to reference type 'int&'
       data() _GLIBCXX_NOEXCEPT
       ^~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1059:7: error: forming pointer to reference type 'int&'
       data() const _GLIBCXX_NOEXCEPT
       ^~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1090:7: error: void std::vector<_Tp, _Alloc>::push_back(std::vector<_Tp, _Alloc>::value_type&&) [with _Tp = int&; _Alloc = std::allocator<int&>; std::vector<_Tp, _Alloc>::value_type = int&]' cannot be overloaded with 'void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = int&; _Alloc = std::allocator<int&>; std::vector<_Tp, _Alloc>::value_type = int&]'
       push_back(value_type&& __x)
       ^~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:1074:7: note: previous declaration 'void std::vector<_Tp, _Alloc>::push_back(const value_type&) [with _Tp = int&; _Alloc = std::allocator<int&>; std::vector<_Tp, _Alloc>::value_type = int&]'
       push_back(const value_type& __x)
       ^~~~~~~~~
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/utility:76,
                 from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_uninitialized.h:60,
                 from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:63,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/initializer_list: In instantiation of 'class std::initializer_list<int&>':
referror2.cpp:9:21:   required from 'Arr<T, SZ>::Arr() [with T = int&; int& SZ = size]'
referror2.cpp:22:18:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/initializer_list:54:26: error: forming pointer to reference type 'int&'
       typedef const _E*  iterator;
                          ^~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/initializer_list:55:26: error: forming pointer to reference type 'int&'
       typedef const _E*  const_iterator;
                          ^~~~~~~~~~~~~~
In file included from /usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/vector:64,
                 from referror2.cpp:1:
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h: In instantiation of 'std::vector<_Tp, _Alloc>::~vector() [with _Tp = int&; _Alloc = std::allocator<int&>]':
referror2.cpp:5:7:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:567:30: error: struct std::_Vector_base<int&, std::allocator<int&> >::_Vector_impl' has no member named '_M_start'
  std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
                ~~~~~~~~~~~~~~^~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:567:54: error: struct std::_Vector_base<int&, std::allocator<int&> >::_Vector_impl' has no member named '_M_finish'
  std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
                                        ~~~~~~~~~~~~~~^~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h: In instantiation of 'std::_Vector_base<_Tp, _Alloc>::~_Vector_base() [with _Tp = int&; _Alloc = std::allocator<int&>]':
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:570:7:   required from 'std::vector<_Tp, _Alloc>::~vector() [with _Tp = int&; _Alloc = std::allocator<int&>]'
referror2.cpp:5:7:   required from here
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:285:24: error: struct std::_Vector_base<int&, std::allocator<int&> >::_Vector_impl' has no member named '_M_start'
  _M_deallocate(_M_impl._M_start,
                ~~~~~~~~^~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:286:17: error: struct std::_Vector_base<int&, std::allocator<int&> >::_Vector_impl' has no member named '_M_end_of_storage'
         _M_impl._M_end_of_storage - _M_impl._M_start);
         ~~~~~~~~^~~~~~~~~~~~~~~~~
/usr/local/Cellar/gcc/8.1.0/include/c++/8.1.0/bits/stl_vector.h:286:45: error: struct std::_Vector_base<int&, std::allocator<int&> >::_Vector_impl' has no member named '_M_start'
         _M_impl._M_end_of_storage - _M_impl._M_start);
                                     ~~~~~~~~^~~~~~~~
```
#まとめ

| cpp | clang++ |  | g++ |  |
|:--|:--|:--|:--|:--|
|  | =-std=c++03 | =-std=c++2a | =-std=c++03 | =-std=c++2a |
| referror2 | 15 | 17 | 30 | 20 |

##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の方がエラーが多い。
2)役に立つまたは意味のあるその他の出力

#参考資料(reference)
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 <misra_c.h>
https://qiita.com/kaizen_nagoya/items/f1a79a7cbd281607c7c9

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


<この項は書きかけです。順次追記します。>
This article is not completed. I will add some words and/or centences in order.
# 自己記事一覧
Qiitaで逆リンクを表示しなくなったような気がする。時々、スマフォで表示するとあらわっることがあり、完全に削除したのではなさそう。

４月以降、せっせとリンクリストを作り、統計を取って確率を説明しようとしている。
2025年２月末を目標にしている。

一覧の一覧( The directory of directories of mine.) Qiita(100)
https://qiita.com/kaizen_nagoya/items/7eb0e006543886138f39

仮説（0）一覧（目標100現在40）
https://qiita.com/kaizen_nagoya/items/f000506fe1837b3590df

Qiita(0)Qiita関連記事一覧（自分）
https://qiita.com/kaizen_nagoya/items/58db5fbf036b28e9dfa6

Error一覧 error(0)
https://qiita.com/kaizen_nagoya/items/48b6cbc8d68eae2c42b8

C++ Support(0)　
https://qiita.com/kaizen_nagoya/items/8720d26f762369a80514

Coding(0) Rules, C, Secure, MISRA and so on
https://qiita.com/kaizen_nagoya/items/400725644a8a0e90fbb0

Ethernet 記事一覧　Ethernet(0)
https://qiita.com/kaizen_nagoya/items/88d35e99f74aefc98794

Wireshark 一覧 wireshark(0)、Ethernet(48) 
https://qiita.com/kaizen_nagoya/items/fbed841f61875c4731d0

線網（Wi-Fi）空中線(antenna)(0) 記事一覧(118/300目標)
https://qiita.com/kaizen_nagoya/items/5e5464ac2b24bd4cd001

なぜdockerで機械学習するか 書籍・ソース一覧作成中 (目標100)
https://qiita.com/kaizen_nagoya/items/ddd12477544bf5ba85e2

プログラムちょい替え（0）一覧:4件
https://qiita.com/kaizen_nagoya/items/296d87ef4bfd516bc394

言語処理100本ノックをdockerで。python覚えるのに最適。:10+12
https://qiita.com/kaizen_nagoya/items/7e7eb7c543e0c18438c4

Python(0)記事をまとめたい。
https://qiita.com/kaizen_nagoya/items/088c57d70ab6904ebb53

安全（0）安全工学シンポジウムに向けて: 21
https://qiita.com/kaizen_nagoya/items/c5d78f3def8195cb2409

プログラマによる、プログラマのための、統計(0)と確率のプログラミングとその後
https://qiita.com/kaizen_nagoya/items/6e9897eb641268766909

転職(0)一覧
https://qiita.com/kaizen_nagoya/items/f77520d378d33451d6fe

物理記事　上位100
https://qiita.com/kaizen_nagoya/items/66e90fe31fbe3facc6ff

量子(0) 計算機, 量子力学 
https://qiita.com/kaizen_nagoya/items/1cd954cb0eed92879fd4

数学関連記事１００
https://qiita.com/kaizen_nagoya/items/d8dadb49a6397e854c6d

統計(0)一覧
https://qiita.com/kaizen_nagoya/items/80d3b221807e53e88aba

図(0) state, sequence and timing. UML and お絵描き 
https://qiita.com/kaizen_nagoya/items/60440a882146aeee9e8f

品質一覧 
https://qiita.com/kaizen_nagoya/items/2b99b8e9db6d94b2e971

言語・文学記事　１００
https://qiita.com/kaizen_nagoya/items/42d58d5ef7fb53c407d6

医工連携関連記事一覧
https://qiita.com/kaizen_nagoya/items/6ab51c12ba51bc260a82

自動車　記事　１００
https://qiita.com/kaizen_nagoya/items/f7f0b9ab36569ad409c5

通信記事１００
https://qiita.com/kaizen_nagoya/items/1d67de5e1cd207b05ef7

日本語（０）一欄
https://qiita.com/kaizen_nagoya/items/7498dcfa3a9ba7fd1e68

英語(0) 一覧
https://qiita.com/kaizen_nagoya/items/680e3f5cbf9430486c7d


音楽　一覧(0) 
https://qiita.com/kaizen_nagoya/items/b6e5f42bbfe3bbe40f5d

「@kazuo_reve 新人の方によく展開している有益な情報」確認一覧 
https://qiita.com/kaizen_nagoya/items/b9380888d1e5a042646b

鉄道（０）鉄道のシステム考察はてっちゃんがてつだってくれる
https://qiita.com/kaizen_nagoya/items/faa4ea03d91d901a618a

OSEK OS設計の基礎　OSEK(100)
https://qiita.com/kaizen_nagoya/items/7528a22a14242d2d58a3

coding (101) 一覧を作成し始めた。omake:最近のQiitaで表示しない5つの事象
https://qiita.com/kaizen_nagoya/items/20667f09f19598aedb68

官公庁・学校・公的団体（NPOを含む）システムの課題、官（０）
https://qiita.com/kaizen_nagoya/items/04ee6eaf7ec13d3af4c3

「はじめての」シリーズ　 ベクタージャパン　
https://qiita.com/kaizen_nagoya/items/2e41634f6e21a3cf74eb

AUTOSAR(0)Qiita記事一覧, OSEK(75)
https://qiita.com/kaizen_nagoya/items/89c07961b59a8754c869

プログラマが知っていると良い「公序良俗」
https://qiita.com/kaizen_nagoya/items/9fe7c0dfac2fbd77a945

LaTeX(0) 一覧　
https://qiita.com/kaizen_nagoya/items/e3f7dafacab58c499792

自動制御、制御工学一覧（０）
https://qiita.com/kaizen_nagoya/items/7767a4e19a6ae1479e6b

Rust(0) 一覧　
https://qiita.com/kaizen_nagoya/items/5e8bb080ba6ca0281927

# 関連資料
' @kazuo_reve 私が効果を確認した「小川メソッド」
https://qiita.com/kazuo_reve/items/a3ea1d9171deeccc04da

' @kazuo_reve 新人の方によく展開している有益な情報
https://qiita.com/kazuo_reve/items/d1a3f0ee48e24bba38f1

' @kazuo_reve Vモデルについて勘違いしていたと思ったこと
https://qiita.com/kazuo_reve/items/46fddb094563bd9b2e1e


## Engineering Festa 2024前に必読記事一覧
programの本質は計画だ。programは設計だ。
https://qiita.com/kaizen_nagoya/items/c8545a769c246a458c27

登壇直後版 色使い(JIS安全色) Qiita Engineer Festa 2023〜私しか得しないニッチな技術でLT〜 スライド編 0.15
https://qiita.com/kaizen_nagoya/items/f0d3070d839f4f735b2b

プログラマが知っていると良い「公序良俗」
https://qiita.com/kaizen_nagoya/items/9fe7c0dfac2fbd77a945

逆も真：社会人が最初に確かめるとよいこと。OSEK(69)、Ethernet(59)
https://qiita.com/kaizen_nagoya/items/39afe4a728a31b903ddc

統計の嘘。仮説（127）
https://qiita.com/kaizen_nagoya/items/63b48ecf258a3471c51b

自分の言葉だけで論理展開できるのが天才なら、文章の引用だけで論理展開できるのが秀才だ。仮説（136）
https://qiita.com/kaizen_nagoya/items/97cf07b9e24f860624dd

参考文献駆動執筆(references driven writing)・デンソークリエイト編
https://qiita.com/kaizen_nagoya/items/b27b3f58b8bf265a5cd1

「何を」よりも「誰を」。１０年後のために今見習いたい人たち
https://qiita.com/kaizen_nagoya/items/8045978b16eb49d572b2

Qiitaの記事に３段階または５段階で到達するための方法
https://qiita.com/kaizen_nagoya/items/6e9298296852325adc5e

出力(output)と呼ばないで。これは状態(state)です。
https://qiita.com/kaizen_nagoya/items/80b8b5913b2748867840

coding (101) 一覧を作成し始めた。omake:最近のQiitaで表示しない5つの事象
https://qiita.com/kaizen_nagoya/items/20667f09f19598aedb68

あなたは「勘違いまとめ」から、勘違いだと言っていることが勘違いだといくつ見つけられますか。人間の間違い(human error(125))の種類と対策
https://qiita.com/kaizen_nagoya/items/ae391b77fffb098b8fb4

プログラマの「プログラムが書ける」思い込みは強みだ。３つの理由。仮説（168）統計と確率(17) , OSEK(79)
https://qiita.com/kaizen_nagoya/items/bc5dd86e414de402ec29

出力(output)と呼ばないで。これは状態(state)です。
https://qiita.com/kaizen_nagoya/items/80b8b5913b2748867840

これからの情報伝達手段の在り方について考えてみよう。炎上と便乗。
https://qiita.com/kaizen_nagoya/items/71a09077ac195214f0db

ISO/IEC JTC1 SC7 Software and System Engineering
https://qiita.com/kaizen_nagoya/items/48b43f0f6976a078d907

アクセシビリティの知見を発信しよう！（再び）
https://qiita.com/kaizen_nagoya/items/03457eb9ee74105ee618

統計論及確率論輪講（再び）
https://qiita.com/kaizen_nagoya/items/590874ccfca988e85ea3

読者の心をグッと惹き寄せる7つの魔法
https://qiita.com/kaizen_nagoya/items/b1b5e89bd5c0a211d862

「@kazuo_reve 新人の方によく展開している有益な情報」確認一覧
https://qiita.com/kaizen_nagoya/items/b9380888d1e5a042646b

ソースコードで議論しよう。日本語で議論するの止めましょう（あるプログラミング技術の議論報告）
https://qiita.com/kaizen_nagoya/items/8b9811c80f3338c6c0b0

脳内コンパイラの3つの危険
https://qiita.com/kaizen_nagoya/items/7025cf2d7bd9f276e382

心理学の本を読むよりはコンパイラ書いた方がよくね。仮説（34）
https://qiita.com/kaizen_nagoya/items/fa715732cc148e48880e

NASAを超えるつもりがあれば読んでください。
https://qiita.com/kaizen_nagoya/items/e81669f9cb53109157f6

データサイエンティストの気づき!「勉強して仕事に役立てない人。大嫌い!!」『それ自分かも?』ってなった!!! 
https://qiita.com/kaizen_nagoya/items/d85830d58d8dd7f71d07

「ぼくの好きな先生」「人がやらないことをやれ」プログラマになるまで。仮説（37）　
https://qiita.com/kaizen_nagoya/items/53e4bded9fe5f724b3c4

なぜ経済学徒を辞め、計算機屋になったか（経済学部入学前・入学後・卒業後対応） 転職(1)  
https://qiita.com/kaizen_nagoya/items/06335a1d24c099733f64    

プログラミング言語教育のXYZ。 仮説（52） 
https://qiita.com/kaizen_nagoya/items/1950c5810fb5c0b07be4

【24卒向け】9ヶ月後に年収１０００万円を目指す。二つの関門と三つの道。
https://qiita.com/kaizen_nagoya/items/fb5bff147193f726ad25

「【25卒向け】Qiita Career Meetup for STUDENT」予習の勧め
https://qiita.com/kaizen_nagoya/items/00eadb8a6e738cb6336f

大学入試不合格でも筆記試験のない大学に入って卒業できる。卒業しなくても博士になれる。
https://qiita.com/kaizen_nagoya/items/74adec99f396d64b5fd5

全世界の不登校の子供たち「博士論文」を書こう。世界子供博士論文遠隔実践中心 安全(99)
https://qiita.com/kaizen_nagoya/items/912d69032c012bcc84f2

小川メソッド　覚え（書きかけ）
https://qiita.com/kaizen_nagoya/items/3593d72eca551742df68

DoCAP（ドゥーキャップ）って何ですか？
https://qiita.com/kaizen_nagoya/items/47e0e6509ab792c43327

views 20,000越え自己記事一覧
https://qiita.com/kaizen_nagoya/items/58e8bd6450957cdecd81

Views１万越え、もうすぐ１万記事一覧 最近いいねをいただいた213記事
https://qiita.com/kaizen_nagoya/items/d2b805717a92459ce853

amazon 殿堂入りNo1レビュアになるまで。仮説(102)
https://qiita.com/kaizen_nagoya/items/83259d18921ce75a91f4

100以上いいねをいただいた記事16選
https://qiita.com/kaizen_nagoya/items/f8d958d9084ffbd15d2a

小川清最終講義、最終講義（再）計画, Ethernet(100) 英語(100) 安全(100)
https://qiita.com/kaizen_nagoya/items/e2df642e3951e35e6a53

＜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。＞
This article is an individual impression based on my individual experience. It has nothing to do with the organization or business to which I currently belong.
### 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。
### 最後までおよみいただきありがとうございました。
いいね　💚、フォローをお願いします。
#### Thank you very much for reading to the last sentence.
Please press the like icon 💚　and follow me for your happy life.