refs #584 Moved hash related stuff to dictionary.h

This also means moving Mixin::Icon from CContainerBase one step down the inheritance hierarchy
to resolve what would otherwise have been a circular include dependency.

src/blackmisc/dictionary.h

@@ -468,6 +468,45 @@ namespace BlackMisc
         }
     }
 
+    namespace Mixin
+    {
+        /*!
+         * CRTP class template from which a derived class can inherit common methods dealing with hashing instances by metatuple.
+         *
+         * \tparam Derived Must be registered with BLACK_DECLARE_TUPLE_CONVERSION.
+         */
+        template <class Derived>
+        class HashByTuple : private Private::EncapsulationBreaker
+        {
+        public:
+            //! qHash overload, needed for storing value in a QSet.
+            friend uint qHash(const Derived &value, uint seed = 0)
+            {
+                return ::qHash(hashImpl(value), seed);
+            }
+
+        private:
+            static uint hashImpl(const Derived &value)
+            {
+                return BlackMisc::qHash(toMetaTuple(value)) ^ baseHash(static_cast<const BaseOfT<Derived> *>(&value));
+            }
+
+            template <typename T> static uint baseHash(const T *base) { return qHash(*base); }
+            static uint baseHash(const void *) { return 0; }
+        };
+    }
+
+    /*!
+     * \brief Calculate a single hash value based on a list of individual hash values
+     * \param values
+     * \param className   add a hash value for class name on top
+     * \return
+     */
+    BLACKMISC_EXPORT uint calculateHash(const QList<uint> &values, const char *className);
+
+    //! Hash value, but with int list
+    BLACKMISC_EXPORT uint calculateHash(const QList<int> &values, const char *className);
+
 } // namespace BlackMisc
 
 #endif // BLACKMISC_DICTIONARY_H