Quicksort Troubles

[MottMan]

I am trying to make a function that uses the quicksort method of sorting. The thing I am having trouble with is returning two separate vectors while recurring them. Here is my quickSort function as of now:

vector <char> quickSort(vector <char> Letters)
{
    if (Letters.size() == 1)
    return Letters;

    int pivot = (rand() % Letters.size());

    vector <char> Less;
    vector <char> Greater;

    Less.reserve(Letters.size());
    Greater.reserve(Letters.size());

    for (int i = 0; i < Letters.size(); i++)
    {
        if (Letters[i] > Letters[pivot])
        {
            Greater.push_back(Letters[i]);
        }
        else
        {
            Less.push_back(Letters[i]);
        }
    }

    //PSEUDO
    return quickSort(Less) + quickSort(Greater);
}

Any nudge in the right direction would be greatly appreciated.

[firedraco]

Check out http://www.cplusplus.com/reference/stl/vector/insert/

[MottMan]

I need to recur both vectors though, so how would I go about doing that? Maybe more than a nudge :)

[ne555]

quicksort can be done in-place.
Instead of passing a vector, you could pass iterators

template<class iterator>
void quicksort(iterator begin, iterator end); // range [) 

If you still want to do it trough copy:

Less = quicksort(Less);
Greater = quicksort(Greater);
return /* Less + Greater */;

[MottMan]

How would I edit my code to work properly? At least to return properly? I should be able to figure out any other problems though.