C++ String Syntax Error

I have been programming for a long time but one thing I never learned is how to make a special type of string. After I type it, it just says: Syntax Error.

Here is my code:

string sysc(string filename){
    string line;
    stringstream string1;
    ifstream inFile;
    inFile.open("C:\\test.txt");

    while(getline(inFile, line))
    {           
        string1<<line<<"\r\n";
    }

    return(string1.str());
};