Function toDouble

src/openms/include/OpenMS/DATASTRUCTURES/StringUtils.h:105–121

@brief convert String (leading and trailing whitespace allowed) to double @p s Input string which represents a double, e.g. " 12.3 " @return A double representation of @p s @throws Exception::ConversionError if the string is not completely explained by the double (whitespaces are allowed) */

      @throws Exception::ConversionError if the string is not completely explained by the double (whitespaces are allowed)
    */
    static double toDouble(const String& s)
    {
      double ret;
      // boost::spirit::qi was found to be vastly superior to boost::lexical_cast or stringstream extraction (especially for VisualStudio),
      // so don't change this unless you have benchmarks for all platforms!
      String::ConstIterator it = s.begin();
      if (!boost::spirit::qi::phrase_parse(it, s.end(), parse_double_, boost::spirit::ascii::space, ret))
      {
        throw Exception::ConversionError(__FILE__, __LINE__, OPENMS_PRETTY_FUNCTION, String("Could not convert string '") + s + "' to a double value");
      }
      // was the string parsed (white spaces are skipped automatically!) completely? If not, we have a problem because a previous split might have used the wrong split char
      if (it != s.end())
      {
        throw Exception::ConversionError(__FILE__, __LINE__, OPENMS_PRETTY_FUNCTION, String("Prefix of string '") + s + "' successfully converted to a double value. Additional characters found at position " + (int)(distance(s.begin(), it) + 1));
      }
      return ret;
    }

    /// Reads a double from an iterator position.
    /// The begin iterator is modified (advanced) if parsing was successful.