Wrong usage of cin.eof()?

I'm using cin to read in words that are then sorted into a vector along with a counter for how many times they have been entered, but the last word always seem to be read in twice.

For exampe, if I enter "foo bar", then it will say:
foo 1
bar 2

instead of:
foo 1
bar 1

I can't find anything wrong with the insert function, so I'm guessing that something is wrong with how the input is received.

Code:

string input;
while (!cin.eof())
{
        cin >> input;
        insert(word_list, input);
}

Code:

void insert (vector<word_entry> &word_list, string input)
{
	// Convert input to lowercase
	transform(input.begin(), input.end(), input.begin(), ::tolower);
			
	vector<word_entry>::iterator i;
	for (i = word_list.begin(); i <= word_list.end(); i++)
	{
		word_entry elem = {input, 1};
		
		if (i == word_list.end())
		{
			word_list.push_back(elem);
			break;
		}
			
		if (i->word.compare(input) > 0)
		{
			word_list.insert(i, elem);
			break;
		}
		else if (i->word.compare(input) == 0)
		{
			i->count++;
			break;
		}
	}
}

eof becomes true only after an attempt to input fails. If the attempt fails, the input string retains its previous value. As a result the last input is stored in the vector one more time.

Input loops are controlled like this:

Code:

while (cin >> input) {
    ...
}

You might want to consider using std::map for this, as it's perfectly suited to what you want to do.

Code:

std::map<string, int> wordMap;
std::vector<string> words;

for(std::vector<string>::iterator i = words.begin(); i != words.end(); i++)
{
     ++wordMap[*i];
}

This is very similar to the wikipedia example. http://en.wikipedia.org/wiki/Map_(C%2B%2B_container)

Okay, thanks! I found some more information on why the return value of cin can be interpreted as a boolean value if anyone is interested: C++ Notes: What values do the I/O operators (<< and >>) return?