# HG changeset patch
# User Eris Caffee <discordia@eldalin.com>
# Date 1435097649 18000
# Node ID 80ca1973e3bdccd2e5ec37f5cfd8f1a08652ce40
# Parent  2cbfacd2a3e986c2c8bb97bc612637c94470bb71
Fleshed out Queue::generic_iterator a bit more to make it a more or less complete example of implmenting an iterator.

diff -r 2cbfacd2a3e9 -r 80ca1973e3bd algs4-c++/src/Queue.cpp
--- a/algs4-c++/src/Queue.cpp	Tue Jun 23 15:46:22 2015 -0500
+++ b/algs4-c++/src/Queue.cpp	Tue Jun 23 17:14:09 2015 -0500
@@ -2,6 +2,7 @@
 
 
 #include <iostream>
+#include <typeinfo>
 
 #include "Queue.hpp"
 
@@ -31,6 +32,9 @@
         std::cout << *iter << std::endl;
         }
 
+    // Just make sure that we can build an iterator with the copy constructor.
+    auto iter = q2.begin();
+    auto iter2( iter );
 
     std::cout << "Dequeuing entries..." << std::endl;
 
@@ -45,5 +49,18 @@
     // Silently empty q2 to avoid the assertion in the destructor.
     while ( ! q2.is_empty() )
         q2.dequeue();
+
+    // Show the iterator traits;
+    std::cout << std::endl;
+    if ( typeid( Queue<long>::iterator_traits::iterator_category) == typeid( std::forward_iterator_tag ) )
+        std::cout << "category: forward iterator" << std::endl;;
+    if ( typeid( Queue<long>::iterator_traits::value_type) == typeid( long ) )
+        std::cout << "value_type: long" << std::endl;;
+    if ( typeid( Queue<long>::iterator_traits::pointer) == typeid( long * ) )
+        std::cout << "pointer: long *" << std::endl;;
+    if ( typeid( Queue<long>::iterator_traits::reference) == typeid( long & ) )
+        std::cout << "reference: long &" << std::endl;;
+    if ( typeid( Queue<long>::iterator_traits::difference_type ) == typeid( ptrdiff_t ) )
+        std::cout << "difference_type: ptrdiff_t" << std::endl;;
     }
 
diff -r 2cbfacd2a3e9 -r 80ca1973e3bd algs4-c++/src/Queue.hpp
--- a/algs4-c++/src/Queue.hpp	Tue Jun 23 15:46:22 2015 -0500
+++ b/algs4-c++/src/Queue.hpp	Tue Jun 23 17:14:09 2015 -0500
@@ -38,6 +38,11 @@
             {
             }
 
+        generic_iterator( const generic_iterator<false>& other ) :
+            curr (other.curr)
+            {
+            }
+
         generic_iterator & operator++() {
             if ( this->curr != nullptr ) {
                 this->curr = this->curr->next;
@@ -58,8 +63,12 @@
             return this->curr->item;
             }
 
-        bool operator!=( generic_iterator other ) {
-            return this->curr != other.curr;
+        bool operator==( generic_iterator rhs ) {
+            return this->curr == rhs.curr;
+            }
+
+        bool operator!=( generic_iterator rhs ) {
+            return this->curr != rhs.curr;
             }
 
     private:
@@ -71,6 +80,7 @@
 
     typedef generic_iterator<true> const_iterator;
     typedef generic_iterator<false> iterator;
+    typedef std::iterator_traits< generic_iterator<> > iterator_traits;
 
     Queue( void );
     ~Queue( void );