DER: In visitor code, use ndnboost::any. We can use ndnboost::any because this is an internal header and will not conflict with the application if it uses boost::any.
diff --git a/ndn-cpp/encoding/der/visitor/simple-visitor.hpp b/ndn-cpp/encoding/der/visitor/simple-visitor.hpp
index d54c499..73991f2 100644
--- a/ndn-cpp/encoding/der/visitor/simple-visitor.hpp
+++ b/ndn-cpp/encoding/der/visitor/simple-visitor.hpp
@@ -18,15 +18,15 @@
 class SimpleVisitor : public NoArgumentsVisitor
 {
 public:
-  virtual Any visit(DerBool&           ) = 0;
-  virtual Any visit(DerInteger&        ) = 0;
-  virtual Any visit(DerPrintableString&) = 0;
-  virtual Any visit(DerBitString&      ) = 0;
-  virtual Any visit(DerNull&           ) = 0;
-  virtual Any visit(DerOctetString&    ) = 0;
-  virtual Any visit(DerOid&            ) = 0;
-  virtual Any visit(DerSequence&       ) = 0;
-  virtual Any visit(DerGtime&          ) = 0;
+  virtual ndnboost::any visit(DerBool&           ) = 0;
+  virtual ndnboost::any visit(DerInteger&        ) = 0;
+  virtual ndnboost::any visit(DerPrintableString&) = 0;
+  virtual ndnboost::any visit(DerBitString&      ) = 0;
+  virtual ndnboost::any visit(DerNull&           ) = 0;
+  virtual ndnboost::any visit(DerOctetString&    ) = 0;
+  virtual ndnboost::any visit(DerOid&            ) = 0;
+  virtual ndnboost::any visit(DerSequence&       ) = 0;
+  virtual ndnboost::any visit(DerGtime&          ) = 0;
 };
 
 } // der