Question

Here is a sample program that uses stringstream. The goal is to accept lines from the user(standard input) and print each word in a separate line.

int main()
{

    std::istringstream currentline;
    std::string eachword;
    std::string line;

    // Accept line from the standard input till EOF is reached
    while ( std::getline(std::cin,line) )
    {
        currentline.str(line); // Convert the input to stringstream
        while ( currentline >> eachword ) // Convert from the entire line to individual word
        {
            std::cout << eachword << std::endl;
        }
        currentline.clear();
    }
    return 0;
}

I’m wondering, is there a way , I can avoid the intermediate string variable(object), line and directly store the user input to the currentline (istringstream object).

Note:

I know, the following solution already.

while ( std::cin >> eachword)
{
    std::cout << eachword << std::endl;
}

Answer 1

std::getline needs a string reference argument, and that’s where it places the line it has obtained, so of course you can’t avoid passing such an argument (and still use that function). You could elegantly encapsulate the construct, if you need it often — e.g.:

bool getline(std::istream& i, std::istringstream& current)
{
    std::string line;
    if ( std::getline(i, line) ) {
        current.str(line);
        return true;
    }
    return false;
}