refs#16

In NumA++ :
- Implement Registry/Factory (as a draft) for Integrator.

include/NumA/integration/IntegratorFactory.h

+class IntegratorFactory {
+
+};

include/NumA/integration/IntegratorRegistry.h

+#ifndef INTEGRATOR_REGISTRY_H
+#define INTEGRATOR_REGISTRY_H
+
+/**
+ * @file IntegratorRegistry.h
+ * @author Bryan BERTHOU (SPhN / CEA Saclay)
+ * @date June 29, 2016
+ * @version 1.0
+ */
+
+namespace NumA {
+
+/**
+ * @class IntegratorRegistry
+ *
+ * @brief
+ */
+class IntegratorRegistry {
+public:
+    /**
+     * Static function to be able to retrieve a unique instance pointer of this class anywhere in the code.
+     *
+     * @return a unique instance of this class
+     */
+    static IntegratorRegistry* getInstance();
+
+    /**
+     * Default destructor
+     */
+    virtual ~IntegratorRegistry();
+
+    unsigned int registerIntegrator(Integrator * pIntegrator);
+
+    /**
+     * Try to find stored object identified by its unique class identifier.
+     *
+     * @param classId
+     * @return reference to object in memory or throw an exception
+     */
+    Integrator* get(unsigned int classId) const;
+
+    /**
+     * Try to find stored object identified by its class name.
+     *
+     * @param className
+     * @return reference to object in memory or throw an exception
+     */
+    Integrator* get(const std::string &className) const;
+
+private:
+    /**
+     * Private pointer of this class for a unique instance
+     */
+    static IntegratorRegistry* m_pInstance;
+
+    /**
+     * Private default constructor for a unique instance
+     */
+    IntegratorRegistry();
+
+    std::map<unsigned int, Integrator*> m_baseObjectList; ///< list of registered objects identified by their unique integer identifier
+    std::map<std::string, Integrator*> m_translateList; ///< list of registered objects identified by their class name.
+};
+
+} // namespace NumA
+
+#endif /* INTEGRATOR_REGISTRY_H */

include/NumA/integration/one_dimension/Integrator.h

+class Integrator {
+public:
+    Integrator();
+    virtual ~Integrator();
+};