OPERATOR PREC, L-VAL, R-VAL, DEREF

Hi All:
I was having problems with pointers, deref, and l-values. So I set up an excercise for myself. Below is the code that I created. IT ALL WORKS THE WAY I WANT. However, I still don't understand deref pointer, oper prec, or l-val's completely.
EX.
(x++)++; l-val missing ok (x++) is an r-val.
(from item #3 in code below)
(*first++)++; How can this work? How is this statement being parsed? Does ++ left to right and * right to left allows this stmt to be parsed?
*(first++)++; Doesn't work? l-val missing ???
Second part, if any of the examples (#3 to #6) can be arranged differently (paranthesis etc.), and still have the same output, please post, and explain.



#include <vector>
#include <typeinfo>
#include <iostream>

using namespace std;

int main (void)
{
      vector<int> v(3);
      v[0] = 5;
      v[1] = 2;
      v[2] = 7;

 int x = 1;
x++;

      vector<int>::iterator first = v.begin();
vector<int>::iterator last  = v.end();
/*
"#1 deref ptr, use val, incr ptr"
VECTOR BEFORE = 5,2,7
OUTPUT 5,2,7
VECTOR AFTER = 5,2,7
"#2 incr ptr, deref ptr, use val"
VECTOR BEFORE = 5,2,7
OUTPUT 2,7
VECTOR AFTER = 5,2,7
"#3 deref ptr, use val, incr val, incr ptr"
VECTOR BEFORE = 5,2,7
OUTPUT 5,2,7
VECTOR AFTER = 6,3,8
"#4 deref ptr, incr val, use val, incr ptr"
VECTOR BEFORE = 5,2,7
OUTPUT 6,3,8
VECTOR AFTER = 6,3,8
"#5 incr ptr, deref ptr, use val, incr val"
VECTOR BEFORE = 5,2,7
OUTPUT 2, 7
VECTOR AFTER = 5,3,8
"#6 incr ptr, deref ptr, incr val, use val"
VECTOR BEFORE = 5,2,7
OUTPUT 3, 8
VECTOR AFTER = 5,3,8
*/


/*      cout << "#1 deref ptr, use val, incr ptr" << endl;
      while (first != last)
            cout <<  *first++ << " ";
*/
/*
      cout << "#2 incr ptr, deref ptr, use val"<< endl;
      do
            cout <<  *++first << " ";
       while (first != (last - 1));
*/
/*      cout << "#3 deref ptr, use val, incr val, incr ptr"<< endl;
      while (first != last)
            cout <<  (*first++)++ << " ";
*/
/*      cout << "#4 deref ptr, incr val, use val, incr ptr"<< endl;
      while (first != last)
            cout <<  ++(*first++) << " ";
*/
/*
      cout << "#5 incr ptr, deref ptr, use val, incr val"<< endl;
      do
            cout <<  (*(++first))++ << " ";
       while (first != (last - 1));
*/
/*      cout << "#6 incr ptr, deref ptr, incr val, use val"<< endl;
      do
            cout <<  ++(*(++first)) << " ";
       while (first != (last - 1));
*/
/* this doesn't work*/
      cout << "#3 deref ptr, use val, incr val, incr ptr"<< endl;
      while (first != last)
            cout <<  *(first++)++ << " ";

  // Iterator is used to loop through the vector.
    vector<int>::iterator theIterator;



    // Output contents of theVector.
    cout << endl << "v [ " ;
    for (theIterator = v.begin(); theIterator != v.end();
         theIterator++)
    {
        cout << *theIterator;
        if (theIterator != v.end()-1) cout << ", ";
                                              // cosmetics for the output
    }
    cout << " ]" << endl ;

return (0);
}