why am I getting a error: no instance of an overloaded function "getline" matches the argument list here?

Question

I have looked at a couple of links such as this and this.

Unfortunately I'm just to new of a programmer to figure it out. I would like to have the following as the line while( getline(getline(fin, line) ) because I'm trying to read in the entire line of text from a file. Then I'm trying to figure out if there are any similar words or numbers in that file. I'm writing this in Microsoft visual studio 2012.

#include <iostream>
#include <fstream>
#include <sstream>
#include <cctype>
#include <string>
using namespace std;

// main application entry point
int main(int argc, char * argv[])
{
    string filename;
    ifstream inFile;

    // request the file name from the user
    cout << "Please enter a filename: ";

    // stores the users response in the string called filename
    cin >> (std::cin, filename);

    // opens the file
    inFile.open(filename.c_str());

    // if the file doesn't open
    if (!inFile)
    {
        cout << "Unable to open file: " << filename << endl;

        return -1;

    } // end of if( !inFile )

    // while( getline(getline(fin, line) ) gives me the same error
    while (getline())
    {}

    // close the file
    inFile.close();

} // end of int main( int argc, char* argv[])

Answer 1

why am I getting a error: no instance of an overloaded function “getline” matches the argument list here?

Because you called std::getline() without any arguments, while std::getline() does require arguments:

while( getline() )
{
}

What std::getline() takes, however, is

1. an stream& (where the input comes from)
2. an std::string& (where the input ends up)
3. optionally a char (a delimiter, the default is '\n')

Something like this should do:

std::string line;
while( std::getline(inFile, line) ) {
  // process line 
}

---

Note that your code is quite a mess. Let's walk through it:

int main(int argc, char * argv[])

Since you are not using argc and argv, why pass them? Your compiler should warn you that they aren't used – which is just noise that might distract you from a compiler diagnostic that points at a real issue. Do this instead:

int main()

and the warning is gone.

string filename;
ifstream inFile;

Why define these at the top of the function, when they are used only further down? In C++, it is considered good style to define objects as late as possible, preferably when they can be initialized.

using namespace std;

This is a bad idea that might hurt you badly. Just don't do it.

cin >> ( std::cin, filename );

I have no idea what this is supposed to do, let alone what it actually does, assuming it compiles. What you want instead, is this: std::cin >> filename. Note, however, that this prevents file names containing whitespace. Should that be a problem, employ std::getline() instead.

inFile.open( filename.c_str() );

This is where inFile should have been defined:

std::ifstream inFile( filename.c_str() );

Finally, your explicit closing of the file

inFile.close();

is unnecessary. The destructor of std::ifstream takes care of that anyway.