Added iterator support to the vector class.

In iterator, implemented the iterator diff operator.
Minor renaming of some parameters in the iterator functions.
More tests to exercise the iterator arithmetic.

3 files changed, 60 insertions, 22 deletions

diff --git a/include/iterator b/include/iterator
index b983a1c..3dee58f 100644
--- a/include/iterator
+++ b/include/iterator
@@ -165,27 +165,43 @@ class __wrapper_iterator
 // Forward iterator requirements
 template<typename _IteratorL, typename _IteratorR, typename _Container>
 inline bool
-operator==(const __wrapper_iterator<_IteratorL, _Container>& __lhs,
-	       const __wrapper_iterator<_IteratorR, _Container>& __rhs)
-{ return __lhs.base() == __rhs.base(); }
+operator==(const __wrapper_iterator<_IteratorL, _Container>& lhs,
+	       const __wrapper_iterator<_IteratorR, _Container>& rhs)
+{ return lhs.base() == rhs.base(); }
 
 template<typename _Iterator, typename _Container>
 inline bool
-operator==(const __wrapper_iterator<_Iterator, _Container>& __lhs,
-	       const __wrapper_iterator<_Iterator, _Container>& __rhs)
-{ return __lhs.base() == __rhs.base(); }
+operator==(const __wrapper_iterator<_Iterator, _Container>& lhs,
+	       const __wrapper_iterator<_Iterator, _Container>& rhs)
+{ return lhs.base() == rhs.base(); }
 
 template<typename _IteratorL, typename _IteratorR, typename _Container>
 inline bool
-operator!=(const __wrapper_iterator<_IteratorL, _Container>& __lhs,
-	       const __wrapper_iterator<_IteratorR, _Container>& __rhs)
-{ return __lhs.base() != __rhs.base(); }
+operator!=(const __wrapper_iterator<_IteratorL, _Container>& lhs,
+	       const __wrapper_iterator<_IteratorR, _Container>& rhs)
+{ return lhs.base() != rhs.base(); }
 
 template<typename _Iterator, typename _Container>
 inline bool
-operator!=(const __wrapper_iterator<_Iterator, _Container>& __lhs,
-	       const __wrapper_iterator<_Iterator, _Container>& __rhs)
-{ return __lhs.base() != __rhs.base(); }
+operator!=(const __wrapper_iterator<_Iterator, _Container>& lhs,
+	       const __wrapper_iterator<_Iterator, _Container>& rhs)
+{ return lhs.base() != rhs.base(); }
+
+// operator+ so we support 100 + iterator<>.
+template<typename _Iterator, typename _Container>
+inline __wrapper_iterator<_Iterator, _Container>
+operator+(typename __wrapper_iterator<_Iterator, _Container>::difference_type n,
+	      const __wrapper_iterator<_Iterator, _Container>& i)
+{ return __wrapper_iterator<_Iterator, _Container>(i.base() + n); }
+
+// operator- : diff is supported on iterators.
+
+template<typename _Iterator, typename _Container>
+inline typename __wrapper_iterator<_Iterator, _Container>::difference_type
+operator-(const __wrapper_iterator<_Iterator, _Container>& lhs,
+	      const __wrapper_iterator<_Iterator, _Container>& rhs)
+{ return lhs.base() - rhs.base(); }
+
 
 }  // namespace std
 
diff --git a/include/vector b/include/vector
index 978d4d1..b5f363a 100644
--- a/include/vector
+++ b/include/vector
@@ -34,6 +34,7 @@
 #include <cstdlib>
 #include <cstring>
 #include <algorithm>
+#include <iterator>
 #include <memory>
 #include <type_traits.h>
 
@@ -58,6 +59,8 @@ namespace std {
 template<typename _T>
 class vector
 {
+    typedef vector<_T> vector_type;
+
   public:
     typedef _T         value_type;
     typedef _T*        pointer;
@@ -65,8 +68,8 @@ class vector
     typedef _T&        reference;
     typedef const _T&  const_reference;
 
-    typedef pointer iterator;
-    typedef const_pointer const_iterator;
+    typedef __wrapper_iterator<pointer,vector_type>  iterator;
+    typedef __wrapper_iterator<const_pointer,vector_type> const_iterator;
 
     typedef size_t    size_type;
     typedef ptrdiff_t difference_type;
@@ -112,13 +115,11 @@ class vector
     // @return A reference to the element.
     reference operator[](size_type index) { return *(mBegin + index); }
 
-    // We don't have iterator, use pointers for now.  begin and end
-    // return NULL if the vector has been cleared or not initialized.
-    iterator begin() { return mBegin; }
-    iterator end() { return mBegin + mLength; }
+    iterator begin() { return iterator(mBegin); }
+    iterator end() { return iterator(mBegin + mLength); }
 
-    const_iterator begin() const { return mBegin; }
-    const_iterator end() const { return mBegin + mLength; }
+    const_iterator begin() const { return const_iterator(mBegin); }
+    const_iterator end() const { return const_iterator(mBegin + mLength); }
 
     // Add data at the end of the vector. Constant in time if the
     // memory has been preallocated (e.g using reserve).
diff --git a/tests/test_vector.cpp b/tests/test_vector.cpp
index 99007b7..2412607 100644
--- a/tests/test_vector.cpp
+++ b/tests/test_vector.cpp
@@ -78,7 +78,6 @@ bool testConstructorRepeat()
     {
         const vector<int> vec1(100, 10);
 
-        EXPECT_TRUE(vec1.end() - vec1.begin() == 100);
         for (int i = 0; i < 100; ++i)
         {
             EXPECT_TRUE(vec1[i] == 10);
@@ -239,7 +238,7 @@ bool testPopBack()
     EXPECT_TRUE(vec1.size() == 0);
     EXPECT_TRUE(vec1.capacity() == 0);
     EXPECT_TRUE(vec1.begin() == vec1.end());
-    EXPECT_TRUE(vec1.begin() == NULL);
+    EXPECT_TRUE(vec1.begin().base() == NULL);
 
     CtorDtorCounter instance;
     vector<CtorDtorCounter> vec2(10, instance);
@@ -294,6 +293,28 @@ bool testIterators()
     {
         EXPECT_TRUE(c == *j);
     }
+
+    {
+        const vector<int> vec1(100, 10);
+
+        EXPECT_TRUE(vec1.end().operator-(100) == vec1.begin());
+        EXPECT_TRUE(vec1.end() - 100 == vec1.begin());
+
+        EXPECT_TRUE(100 + vec1.begin() == vec1.end());
+        EXPECT_TRUE(vec1.begin() + 100 == vec1.end());
+
+        EXPECT_TRUE(vec1.end() - vec1.begin() == 100);
+
+        for (vector<int>::const_iterator i = vec1.begin();
+             i != vec1.end(); ++i) {
+            EXPECT_TRUE(*i == 10);
+        }
+    }
+
+    {
+        const vector<int> vec2;
+        EXPECT_TRUE(vec2.begin() == vec2.end());
+    }
     return true;
 }