error - locale name not valid

[SSteven]

The following example is excerpted from Stroustrup's book:

/// ...

void test(istream& fin, ostream& fout,
          istream& fin2, ostream& fout2)
{
   fin.imbue(locale {"en_US.UTF-8"});	/// American English
   fout.imbue(locale {"fr_FR.UTF-8"});	/// French

   /// read American English, write French
   copy(fin, fout);

   /// ...

   fin2.imbue(locale {"fr_FR.UTF-8"});	/// French
   fout2.imbue(locale {"en_US.UTF-8"});	/// American English

   /// read French, write American English
   copy(fin2, fout2);
}

/// ... 

https://ideone.com/zuJEcq


However, I get the following compilation error:

terminate called after throwing an instance of 'std::runtime_error'
  what():  locale::facet::_S_create_c_locale name not valid

Please advise how to proceed in this case. Thanks.

[JLBorges]

Locale names are implementation specific.

In particular, with the GNU library on non-Linux systems, do not rely on anything more than token support for locales: ie. the classic locale ("C"), the posix locale ("POSIX") and the default locale ("").

Ideally, on Windows, either use the Microsoft implementation or use Boost.Locale in conjunction with ICU.