Add a get method that doesn't throw, but returns a default argument instead

MongoDB/include/Poco/MongoDB/Document.h

@@ -141,6 +141,32 @@ public:
 		}
 	}
 
+
+	template<typename T>
+	T get(const std::string& name, const T& def) const
+		/// Returns the element with the given name and tries to convert
+		/// it to the template type. When the element is not found, or
+		/// has the wrong type, the def argument will be returned.
+	{
+		Element::Ptr element = get(name);
+		if ( element.isNull() )
+		{
+			return def;
+		}
+
+		if ( ElementTraits<T>::TypeId == element->type() )
+		{
+			ConcreteElement<T>* concrete = dynamic_cast<ConcreteElement<T>* >(element.get());
+			if ( concrete != NULL )
+			{
+				return concrete->value();
+			}
+		}
+
+		return def;
+	}
+
+
 	Element::Ptr get(const std::string& name) const;
 		/// Returns the element with the given name.
 		/// An empty element will be returned when the element is not found.