// C++N4606 Committee Draft, Standard for Programming Language C++
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/n4606.pdf
#define msg "C++N460(269)28.7 Class template regex_traits [re.traits]p1293.cpp"
// Edited by Dr. Ogawa Kiyoshi. Compile procedure and results record.

#include <iostream>
#include <cstdlib>
#include <regex> ///for regex_traits

using namespace std;

int main() {

  regex_traits<char> t;
  string d("d");
  string u("upper");
  regex_traits<char>::char_class_type f;
  f = t.lookup_classname(d.begin(), d.end());
  f |= t.lookup_classname(u.begin(), u.end());
  ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper

  regex_traits<char> t2;
  string w("w");
  regex_traits<char>::char_class_type f2;
  f2 = t2.lookup_classname(w.begin(), w.end());
  t2.isctype('A', f2); // returns true
  t2.isctype('_', f2); // returns true
  t2.isctype(' ', f2); // returns false

  std::cout<< msg << std::endl;
  return EXIT_SUCCESS;
}

$ ./cppall.sh p1293
$ clang++ p1293.cpp -std=c++03 -Wall
p1293.cpp:20:22: error: use of undeclared identifier 'convert'
ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                     ^
p1293.cpp:20:34: error: expected '(' for function-style cast or type construction
ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                             ~~~~^
2 errors generated.
$ clang++ p1293.cpp -std=c++11 -Wall
p1293.cpp:20:22: error: use of undeclared identifier 'convert'
ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                     ^
p1293.cpp:20:34: error: expected '(' for function-style cast or type construction
ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                             ~~~~^
2 errors generated.
$ clang++ p1293.cpp -std=c++17 -Wall
p1293.cpp:20:22: error: use of undeclared identifier 'convert'
ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                     ^
p1293.cpp:20:34: error: expected '(' for function-style cast or type construction
ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                             ~~~~^
2 errors generated.

$ g++-7 p1293.cpp -std=c++03  -Wall
In file included from /usr/local/Cellar/gcc/7.3.0_1/include/c++/7.3.0/regex:35:0,
                 from p1293.cpp:8:
/usr/local/Cellar/gcc/7.3.0_1/include/c++/7.3.0/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.
 #error This file requires compiler and library support \
  ^~~~~
p1293.cpp: In function 'int main()':
p1293.cpp:14:1: error: 'regex_traits' was not declared in this scope
 regex_traits<char> t;
 ^~~~~~~~~~~~
p1293.cpp:14:14: error: expected primary-expression before 'char'
 regex_traits<char> t;
              ^~~~
p1293.cpp:17:14: error: expected primary-expression before 'char'
 regex_traits<char>::char_class_type f;
              ^~~~
p1293.cpp:18:1: error: 'f' was not declared in this scope
 f = t.lookup_classname(d.begin(), d.end());
 ^
p1293.cpp:18:5: error: 't' was not declared in this scope
 f = t.lookup_classname(d.begin(), d.end());
     ^
p1293.cpp:20:22: error: 'convert' was not declared in this scope
 ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                      ^~~~~~~
p1293.cpp:20:30: error: expected primary-expression before 'char'
 ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                              ^~~~
p1293.cpp:22:14: error: expected primary-expression before 'char'
 regex_traits<char> t2;
              ^~~~
p1293.cpp:24:14: error: expected primary-expression before 'char'
 regex_traits<char>::char_class_type f2;
              ^~~~
p1293.cpp:25:1: error: 'f2' was not declared in this scope
 f2 = t2.lookup_classname(w.begin(), w.end());
 ^~
p1293.cpp:25:6: error: 't2' was not declared in this scope
 f2 = t2.lookup_classname(w.begin(), w.end());
      ^~
p1293.cpp:25:6: note: suggested alternative: 'tm'
 f2 = t2.lookup_classname(w.begin(), w.end());
      ^~
      tm
p1293.cpp:20:18: warning: unused variable 'm' [-Wunused-variable]
 ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                  ^

$ g++-7 p1293.cpp -std=c++11  -Wall
p1293.cpp: In function 'int main()':
p1293.cpp:20:22: error: 'convert' was not declared in this scope
 ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                      ^~~~~~~
p1293.cpp:20:30: error: expected primary-expression before 'char'
 ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                              ^~~~
p1293.cpp:20:18: warning: unused variable 'm' [-Wunused-variable]
 ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                  ^

$ g++-7 p1293.cpp -std=c++17  -Wall
p1293.cpp: In function 'int main()':
p1293.cpp:20:22: error: 'convert' was not declared in this scope
 ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                      ^~~~~~~
p1293.cpp:20:30: error: expected primary-expression before 'char'
 ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                              ^~~~
p1293.cpp:20:18: warning: unused variable 'm' [-Wunused-variable]
 ctype_base::mask m = convert<char>(f); // m == ctype_base::digit|ctype_base::upper
                  ^