title: C++. Convert char* with unicode (UTF-8) symbols to std::wstring
body: <p>I faced with pretty common problem, but I can't find solution for this. tinyxml2 library returning <code>const char*</code> with <code>Attribute(const char*)</code> method. In xml file, opened with that library, I have attributes with unicode and without. File converted to UTF-8. Using Linux, but it would be nice to see solution for windows too. Any suggestions?</p>