Why am I getting “No viable conversion from 'vector<Country>' to 'int'”?

Question

I'm really not sure as to why I am receiving this error. I've tried to google it but I haven't had the best of results... If somebody could just tell me as to why I'm getting this error:

No viable conversion from 'vector<Country>' to 'int'

int main()
{
    vector<Country> readCountryInfo(const string& filename);

    // Creating empty vector
    vector<Country> myVector;

    // Opening file
    ifstream in;
    in.open("worldpop.txt");

    if (in.fail()) {
        throw invalid_argument("invalid file name");
    }

    while (in) {

        char buffer; // Character buffer
        int num; // Integer to hold population
        string countryName; // Add character buffer to create name

        while (in.get(buffer)) {

            // Check if buffer is a digit
            if (isdigit(buffer)) {
                in.unget();
                in >> num;
            }

            // Check if buffer is an alphabetical character
            else if (isalpha(buffer) || (buffer == ' ' && isalpha(in.peek()))) {
                countryName += buffer;
            }

            // Checking for punctuation to print
            else if (ispunct(buffer)) {
                countryName += buffer;
            }

            // Check for new line or end of file
            else if (buffer == '\n' || in.eof()) {
                // Break so it doesn't grab next char from inFile when running loop
                break;
            }

        }

        Country newCountry = {countryName, num};
        myVector.push_back(newCountry);

    }

    return myVector;

}

Answer 1

It says here

int main()

that main returns an int — as it should, because The Standard requires it to.

Then, at the end, you say

return myVector;

and myVector is a vector<Country> , which can't be converted to an int .
Hence the error message.

I suspect, based on the declaration

vector<Country> readCountryInfo(const string& filename);

of a function that does return a vector<Country> , that you intended to write your code in a function called "readCountryInfo", but somehow happened to write it in the wrong place.

Answer 2

Your int main() should return an int, not myVector (last line of your code).

In c++, main returns an int, normally zero.