Changed the parameter type comparer to work with qualified types because overriding cannot change the qualification of types.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>

src/AST/Type.cs

@@ -181,6 +181,16 @@ namespace CppSharp.AST
             return Type.Equals(type.Type) && Qualifiers.Equals(type.Qualifiers);
         }
 
+        public static bool operator ==(QualifiedType left, QualifiedType right)
+        {
+            return left.Equals(right);
+        }
+
+        public static bool operator !=(QualifiedType left, QualifiedType right)
+        {
+            return !(left == right);
+        }
+
         public override int GetHashCode()
         {
             return base.GetHashCode();

src/Generator/Passes/GenerateAbstractImplementationsPass.cs

@@ -87,7 +87,7 @@ namespace CppSharp.Passes
             {
                 var @abstract = abstractMethods[i];
                 if (overriddenMethods.Find(m => m.Name == @abstract.Name &&
-                    m.ReturnType.Type == @abstract.ReturnType.Type &&
+                    m.ReturnType == @abstract.ReturnType &&
                     m.Parameters.Count == @abstract.Parameters.Count &&
                     m.Parameters.SequenceEqual(@abstract.Parameters, paramTypeCmp)) != null)
                 {

src/Generator/Utils/ParameterTypeComparer.cs

@@ -7,7 +7,7 @@ namespace CppSharp.Utils
     {
         public bool Equals(Parameter x, Parameter y)
         {
-            return x.Type == y.Type;
+            return x.QualifiedType == y.QualifiedType;
         }
 
         public int GetHashCode(Parameter obj)