Add new connection trait.

src/mlpack/methods/ann/connections/connection_traits.hpp

@@ -31,6 +31,11 @@ class ConnectionTraits
    * This is true if the connection is a fullself connection.
    */
   static const bool IsFullselfConnection = false;
+
+  /**
+   * This is true if the connection is a pooling connection.
+   */
+  static const bool IsPoolingConnection = false;
 };
 
 }; // namespace ann

src/mlpack/methods/ann/connections/fullself_connection.hpp

@@ -154,6 +154,7 @@ class ConnectionTraits<
  public:
   static const bool IsSelfConnection = false;
   static const bool IsFullselfConnection = true;
+  static const bool IsPoolingConnection = false;
 };
 
 }; // namespace ann

src/mlpack/methods/ann/connections/self_connection.hpp

@@ -159,6 +159,7 @@ class ConnectionTraits<
  public:
   static const bool IsSelfConnection = true;
   static const bool IsFullselfConnection = false;
+  static const bool IsPoolingConnection = false;
 };
 
 }; // namespace ann