std::vector to string with custom delimiter

Question

I would like to copy the contents of a vector to one long string with a custom delimiter. So far, I\'ve tried:

// .h
string getLabe         


        

Answer 1

string join(const vector & v, const string & delimiter = ",") {
    string out;
    if (auto i = v.begin(), e = v.end(); i != e) {
        out += *i++;
        for (; i != e; ++i) out.append(delimiter).append(*i);
    }
    return out;
}

A few points:

• you don't need an extra conditional to avoid an extra trailing delimiter
• make sure you don't crash when the vector is empty
• don't make a bunch of temporaries (e.g. don't do this: x = x + d + y)