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From: "Andrew Wu (andrewwu DOT tw AT gmail DOT com) [via djgpp AT delorie DOT com]" <djgpp AT delorie DOT com>
Date: Fri, 21 Jul 2017 20:56:51 +0800
Message-ID: <CANbeq3zwqk7eSiR1f+2tgdiztpC_B=HQN42WPwt+sgtbQUcz2g@mail.gmail.com>
Subject: DJGPP doesn't support std::wstring?
To: "djgpp AT delorie DOT com" <djgpp AT delorie DOT com>
Content-Type: text/plain; charset="UTF-8"
Reply-To: djgpp AT delorie DOT com

Hello,

I found the following code :

#include <string>
int main()
{
  std::string s;
  std::wstring w;
  return 0;
}

DJGPP 7.1.0 can't compile it. DJGPP will report:

test.cpp: In function 'int main()':
test.cpp:5:6: error: 'wstring' is not a member of 'std'
std::wstring w;
      ^~~~~~~
test.cpp:5:6: note: suggested alternative: 'isprint'
std::wstring w;
      ^~~~~~~
      isprint

Other versions of DJGPP also have the same problem. It seems DJGPP
doesn't support std::wstring?

I checked DJGPP header files, I found in
\djgpp\include\cxx\7\bits\stringfwd.h , there is :

#ifdef _GLIBCXX_USE_WCHAR_T
  /// A string of @c wchar_t
  typedef basic_string<wchar_t> wstring;
#endif

And in \djgpp\include\cxx\7\debug\string , there is :

#ifdef _GLIBCXX_USE_WCHAR_T
  typedef basic_string<wchar_t> wstring;
#endif

So, I think it is needed to define _GLIBCXX_USE_WCHAR_T to declare
wstring class in the header files. But this symbol is not defined in
\djgpp\include\cxx\7\djgpp\bits\cxxconfig.h :

/* Define if code specialized for wchar_t should be used. */
/* #undef _GLIBCXX_USE_WCHAR_T */

So wstring class is not declared.

If I use cxx -D_GLIBCXX_USE_WCHAR_T to define it, DJGPP will report
other more problems.

Any method to support wstring in DJGPP?


This problem is originally from :
https://github.com/andrewwutw/build-djgpp/issues/16