[Boost-users] [program_options] exceptions

From: Filip Konvička (filip.konvicka_at_[hidden])
Date: 2008-02-11 10:22:35

Hi,

I started using the program_options library and I have a question about 
using the exceptions thrown by the library. I'd like to localize the 
errors reported by the library, but I can't see why the members of the 
exception classes are private, or why are there no getters to retrieve 
the properties needed to re-construct the messages in another language.

Also, I can't make default wstring values work...my attempt is:

#include <boost/program_options.hpp>
#include <string>
using namespace std;
using namespace boost::program_options;
int main() {
  wstring             lang;
  options_description lang_opt_desc;
  variables_map       vm;
  lang_opt_desc.add_options()
    ("lang", wvalue<wstring>(&lang)->default_value(L"en_US"), "Language 
ID.")
  return 0;
}

fails with both gcc and msvc, saying that

  boost/lexical_cast.hpp(174) : error C2679: binary '=' : no operator 
found which takes a right-hand operand
     of type 'std::basic_string<_Elem,_Traits,_Ax>' (or there is no 
acceptable conversion)

(I'm using Boost 1.34.1 with MSVC 9.0 and g++ 4.2.3). I looked in the 
code and it looks that I could use

    ...
    ("lang", wvalue<wstring>(&lang)->default_value(L"en_US", "en_US"), 
"Language ID.")
    ...

which works fine...I just wanted to know whether this is the intended 
approach.

Thanks,
Filip