code style: Don't use std:: inside .cpp files.
diff --git a/ndn-cpp/encoding/der/visitor/print-visitor.cpp b/ndn-cpp/encoding/der/visitor/print-visitor.cpp
index ab56b5d..cba5d2d 100644
--- a/ndn-cpp/encoding/der/visitor/print-visitor.cpp
+++ b/ndn-cpp/encoding/der/visitor/print-visitor.cpp
@@ -50,7 +50,7 @@
const string& indent = ndnboost::any_cast<const string&>(param);
printData(derBStr.getHeader(), indent);
- const std::vector<uint8_t>& payload = derBStr.getPayload();
+ const vector<uint8_t>& payload = derBStr.getPayload();
cout << indent << " " << " " << hex << setw(2) << setfill('0') << (int)(uint8_t)payload[0] << endl;
printData(payload, indent + " ", 1);
}