c++ - std::bad_cast when using std::basic_istringstream<unsigned short> -


i'm trying process utf-16 string (placed in buffer buf) of std::basic_string , istringstream. exception std::bad_cast occurs in code. there problem code? or gcc's stl cannot handle unsigned int (16 bit) symbols?

const unsigned short * buf; // ... fiilling buf std::basic_string<unsigned short> w(buf); std::basic_istringstream<unsigned short> iss(w);  unsigned int result; try { iss >> result; } catch (std::exception& e) {    const char * c = e.what(); }

the same code std::wstring , std::wistringstream works correctly.

instantiation of iostreams on different character types char , wchar_t rather non-trivial. streams need number of std::locale facets present. without them won't function properly. attempted operation you'd need, @ least:

  • std::ctype<ct>
  • std::numpunct<ct>
  • std::num_get<ct>

where ct stream's character type. last 1 of these should require instantiation others need implemented. of course, need make sure std::locale installed stream either setting global locale or using stream.imbue().

personally, think overall wrong approach, though: characters should converted internal representation when entering system , converted external representation when leaving system (that's purpose of std::codecvt<...> facet). seems, however, lost fight , people feel want mess encodings internally.


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