C++, remove all duplicated, multiple value in sorted vector

template <class T>
void removeAllDuplicates(vector<T>& vec) {
    size_t i;
    size_t pos = 0;
    for (i = 1; i < vec.size(); i++) {
        if (vec[i] != vec[pos]) {
            pos++;
            vec[pos] = vec[i];
        }
    }
    vec.erase(vec.begin() + pos + 1, vec.end());
}