Method ExtractOperatorToken

libraries/muparser/src/muParserTokenReader.cpp:392–411

\brief Check Expression for the presence of a binary operator token. Userdefined binary operator "++" gives inconsistent parsing result for the equations "a++b" and "a ++ b" if alphabetic characters are allowed in operator tokens. To avoid this this function checks specifically for operator tokens. */

	  for operator tokens.
	*/
	int ParserTokenReader::ExtractOperatorToken(string_type& a_sTok, std::size_t a_iPos) const
	{
		// Changed as per Issue 6: https://code.google.com/p/muparser/issues/detail?id=6
		auto iEnd = m_strFormula.find_first_not_of(m_pParser->ValidOprtChars(), a_iPos);
		if (iEnd == string_type::npos)
			iEnd = m_strFormula.length();

		// Assign token string if there was something found
		if (a_iPos != iEnd)
		{
			a_sTok = string_type(m_strFormula.begin() + a_iPos, m_strFormula.begin() + iEnd);
			return static_cast<int>(iEnd);
		}
		else
		{
			// There is still the chance of having to deal with an operator consisting exclusively
			// of alphabetic characters.
			return ExtractToken(_T("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"), a_sTok, (std::size_t)a_iPos);
		}
	}


	/** \brief Check if a built in operator or other token can be found