std::list iterator: get next element

Question

I\'m trying to build a string using data elements stored in a std::list, where I want commas placed only between the elements (ie, if elements are {A,B,C,D} in list, result stri

Answer 1

You cannot do it + N because you have no random access for list iterators. You can only do one step at a time with list iterators (these are bidirectional iterators).

You can use boost::next and boost::prior

// Lookahead in list to see if next element is end
if(boost::next(iterItems) == dilList.end())  
{

Or you can print the comma before:

std::string Compose(DataItemList& dilList)
{
    std::stringstream ssDataSegment;
    for(iterItems = dilList.begin();
        iterItems != dilList.end(); 
        ++iterItems)
    {
        if(iterItems != diList.begin())
            ssDataSegment << ",";
        ssDataSegment << (*iterItems)->ToString();
    }
    return ssDataSegment.str();
}