Provide const access to entity map in the pool.

include/dynamic-graph/pool.h

@@ -87,6 +87,9 @@ namespace dynamicgraph
     */
     Entity& getEntity (const std::string& name);
 
+    /// Const access to entity map
+    const Entities& getEntityMap () const;
+
     /*! \brief Test if the entity exists. */
     bool existEntity (const std::string& name);
     /*! \brief Test if the entity exists. If it does, return a pointer on it. */

src/dgraph/pool.cpp

@@ -131,6 +131,12 @@ getEntity( const std::string& name )
   else return *entPtr->second;
 }
 
+const PoolStorage::Entities& PoolStorage::
+getEntityMap () const
+{
+  return entityMap;
+}
+
 bool PoolStorage::
 existEntity (const std::string& name)
 {