rem: if (ret == wchar_t(-1)) return s;
add: if (size == wchar_t(-1)) return s;
context: 	std::string utf8_native(std::string const& s)	{		try		{			std::wstring ws;			libtorrent::utf8_wchar(s, ws);			std::size_t size = wcstombs(0, ws.c_str(), 0);			if (size == std::size_t(-1)) return s;			std::string ret;			ret.resize(size);			size = wcstombs(&ret[0], ws.c_str(), size + 1);			if (ret == wchar_t(-1)) return s;			ret.resize(size);			return ret;		}		catch(std::exception)		{			return s;		}	}