.. highlight:: c++
  :linenothreshold: 5

.. _ref-vs-ptr:

************************
Ref type vs pointer type
************************

Difference
==========
* A ref variable cannot be re-assigned
* A ref variable cannot be empty or undefined, not flexible
* Ref type is easier to use with no ref/deref operations
* Ref is safer to use
* Pointer is more powerful and allows many algorithms
* Array is also a pointer
* New and delete only work with pointers

Pass-by-ref vs Pass-by-pointer
==============================
+ Both allow modification of the actual parameter
+ Pass by ref has simpler syntax
+ Pass by pointer allows more complicated logic

::

  // swap pointer version
  // called like swap(&a, &b);
  void swap(int * ptr1, int * ptr2) {
    int tmp = *ptr1;
    *ptr1 = *ptr2;
    *ptr2 = tmp;
  }

  // swap ref version
  // cleaner syntax
  // called like swap(a, b);
  void swap(int & ref1, int & ref2) {
    int tmp = ref1;
    ref1 = ref2;
    ref2 = tmp;
  }