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 getLabeledPointsString(const string delimiter=",");
// .cpp
string Gesture::getLabeledPointsString(const string delimiter) {
    vector<int> x = getLabeledPoints();
    stringstream  s;
    copy(x.begin(),x.end(), ostream_iterator<int>(s,delimiter));
    return s.str();
}

but I get

no matching function for call to ‘std::ostream_iterator<int, char, std::char_traits<char> >::ostream_iterator(std::stringstream&, const std::string&)’

I’ve tried with charT* but I get

error iso c++ forbids declaration of charT with no type

Then I tried using char and ostream_iterator<int>(s,&delimiter)
but I get strange characters in the string.

Can anyone help me make sense of what the compiler is expecting here?

Answer 1

Use delimiter.c_str() as the delimiter:

copy(x.begin(),x.end(), ostream_iterator<int>(s,delimiter.c_str()));

That way, you get a const char* pointing to the string, which is what ostream_operator expects from your std::string.