How to use boost split to split a string and ignore empty values?
boost, c++, parsing, split
Solution
Even though "adjacent separators are merged together", it seems like the trailing delimeters make the problem, since even when they are treated as one, it still is one delimeter.
So your problem cannot be solved with `split()` alone. But luckily Boost String Algo has `trim()` and `trim_if()`, which strip whitespace or delimeters from beginning and end of a string. So just call `trim()` on buf, like this:
std::string buf = "1:1~15 ASTKGPSVFPLAPSS SVFPLAPSS -12.6 98.3 ";
std::vector<std::string> dataLine;
boost::trim_if(buf, boost::is_any_of("\t ")); // could also use plain boost::trim
boost::split(dataLine, buf, boost::is_any_of("\t "), boost::token_compress_on);
std::cout << out.size() << std::endl;
This question was already asked: boost::split leaves empty tokens at the beginning and end of string - is this desired behaviour?
Problem
I am using boost::split to parse a data file. The data file contains lines such as the following. data.txt ``` 1:1~15 ASTKGPSVFPLAPSS SVFPLAPSS -12.6 98.3 ``` The white space between the items are tabs. The code I have to split the above line is as follows. ``` std::string buf; /*Assign the line from the file to buf*/ std::vector<std::string> dataLine; boost::split( dataLine, buf , boost::is_any_of("\t "), boost::token_compress_on); //Split data line cout << dataLine.size() << endl; ``` For the above line of code I should get a print out of 5, but I get 6. I have tried to read through the documentation and this solution seems as though it should do what I want, clearly I am missing something. Thanks! Edit: Running a forloop as follows on dataLine you get the following. ``` cout << "****" << endl; for(int i = 0 ; i < dataLine.size() ; i ++) cout << dataLine[i] << endl; cout << "****" << endl; **** 1:1~15 ASTKGPSVFPLAPSS SVFPLAPSS -12.6 98.3 **** ```