id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
7929	boost::lexical_cast< std::string, std::wstring > gives a compiler error.	nate@…	Vladimir Prus	"This causes a problem with `boost::program_options::typed_value< std::wstring, wchar_t >::default_value( const std::wstring& v )` which attempts to use lexical_cast to convert `v` into a `std::string`. Using `lexical_cast` to convert a wide string to a normal one may be debatable, but program_options should not give a compiler error on a valid use case such as the one shown below. Luckily you can work around this by providing an explicit `std::string` version or not using the `default_value` method at all.

==== lexical_cast error ====
{{{#!cpp
#include <boost/lexical_cast.hpp>
#include <string>

int main( int argc, wchar_t* argv[] ){
    std::wstring wstr = L""some string"";
    std::string str = boost::lexical_cast< std::string >( wstr );

    return 0;
}
}}}

==== program_options error ====
{{{#!cpp
#include <boost/program_options.hpp>
#include <string>

int main( int argc, wchar_t* argv[] ){
    namespace po = boost::program_options;
    po::options_description opts( ""Some opts"" );

    std::wstring str = L"""";
    opts.add_options()
        (
            ""o"",
            po::wvalue< std::wstring >( &str )
                ->default_value( L""default value"" ), // This line causes error.
            ""an option""
        );

    return 0;
}
}}}
"	Bugs	new	To Be Determined	program_options	Boost 1.52.0	Problem			antoshkka@…