cin.eof() functionality

Question

I understand that cin.eof() tests the stream format. And while giving input, end of character is not reached when there is wrong in the input. I tested

Answer 1

Assuming your input is line based, I suggest that you read the whole line using std::getline(). Once you have the line, you can analyse it and decide whether it contains correct or wrong input. Put the line into std::istringstream and do something like the following:

Edit: Changed !! iss to static_cast(iss) for compatibility with C++0x.

std::istringstream iss (line);
char ch;
long lval;
// read the input
iss >> lval;
// result variable will contain true if the input was correct and false otherwise
result
    // check that we have read a number of at least one digit length
    = static_cast(iss)
    // check that we cannot read anything beyond the value read above
    && ! (iss >> ch);