Added test to testChannels unit-test to verify functionality of ChannelList::Iterator/ConstIterator

Signed-off-by: Aries Moczar <arcmantis@protulae.com>

Author: Arcmantis18

src/test/OpenEXRTest/testChannels.cpp

@@ -218,13 +218,79 @@ writeRead (
     cout << endl;
 }
 
+void
+verifyIterators(void)
+{
+    ChannelList l1,l2;
+
+    l1.insert("A", Channel(HALF));
+    l1.insert("B", Channel(HALF));
+    l1.insert("C", Channel(HALF));
+
+    l2 = l1;
+
+    auto it1 = l1.begin();
+    const auto cit1 = l1.begin();
+
+    auto it2 = l2.begin();
+    const auto cit2 = l2.begin();
+
+    // Test global '==' overloads
+    assert(it1 == it1);
+    assert(it1 == cit1);
+    assert(cit1 == it1);
+    assert(cit1 == cit1);
+
+    // Test global '!=' overloads
+    assert(it1 != it2);
+    assert(cit1 != it2);
+    assert(it1 != cit2);
+    assert(cit1 != cit2);
+
+     
+    while (it1 != l1.end())
+    {
+        // Test '*' overloads
+        Channel& c = *it1;
+        const Channel& cc = *it1;
+        assert(c.type == HALF);
+        assert(cc.type == HALF);
+        
+        // Test '->' overload
+        assert(it2->type == HALF);
+        assert(cit2->type == HALF);
+
+        // Test pre/post '++' overloads
+        it1++; 
+        ++it2;
+    }
+
+    assert(it1 == l1.end());
+    assert(it2 == l2.end()); 
+
+    while (it1 != l1.begin())
+    {
+
+        // Test pre/post '--' overloads
+        it1--;
+        --it2;
+    }
+
+    assert(it1 == l1.begin());
+    assert(it2 == l2.begin());
+}
+
 } // namespace
 
 void
 testChannels (const std::string& tempDir)
 {
     try
     {
+        cout << "Testing ChannelList Iterator behavior" << endl;
+
+        verifyIterators ();
+
         cout << "Testing filling of missing channels" << endl;
 
         const int W = 117;