How to make a better design if two overload functions are similar

I'm working on a c++ project and I have a case as below:

void func(int a, int b)
{
    if (some_bool)
    {
        generateString(generateFunc()); // different
    }
    for (auto it : myVector)
    {
        // do something
        for (int i = 0; i < a + b; ++i)
        {
            if (some_bool2)
            {
                myData = generateInt();
            }
            else
            {
                myData2 = generateInt2(); // different
            }
        }
    }
}


void func(int a, int b, string str)
{
    if (some_bool)
    {
        generateString(generateFunc(str));  // different
    }
    for (auto it : myVector)
    {
        // do something
        for (int i = 0; i < a + b; ++i)
        {
            if (some_bool2)
            {
                myData = generateInt();
            }
            else
            {
                myData2 = convertStrToInt(str);  //different
            }
        }
    }
}

As you see, I have two overloading functions.
Their logical structures are the same but some details are not.

I'm considering if there is some technique which can merge them so that I can have a better design. Because for now I have to change two times if I need to do some change.