无效的迭代器比较

Question

I have written this piece of code to find duplicate items in the string vector "elements". A storage for the unique items is kept, and if an item is found in the unique storage it means it's a duplicate:

    vector<string> elements;
    // "elements" is populated ....
    //  ...

    // Find duplicates:
    vector<string> uniqueElements;

    for (int i = 0; i < elements.size(); ++i)
    {
        string name = elements[i];
        vector<string>::iterator it = find(uniqueElements.begin(), uniqueElements.end(), name);

        if(it != uniqueElements.end()) // ERROR
        {
            cerr << "Duplicate element " << name << endl;
            return false;
        }
        uniqueElements.push_back(name);
    }

After the 2nd item in the "elements" vector, when the uniqueElements container is reallocated I am getting a

    vector iterators incompatible

error message. Why does this happen, since I am getting new iterators at the beginning of each loop.

Thanks in advance.

Answer 1

Thank you for the responses,turns out it was something different. In my original code, the error I was printing was

 cerr << "Duplicate element " << name << " at position " << it - elements.begin() <<  endl;

I omitted the exact print content thinking that it was irrelevant, but of course the error was that I was using the iterator on a different vector. Sorry for the trouble.