build: switch to C++17

Change-Id: I119767c48c085c62556347ba6c11a85e30c32ced
diff --git a/src/common.cpp b/src/common.cpp
index da4c5fd..45488b1 100644
--- a/src/common.cpp
+++ b/src/common.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2014-2018, Regents of the University of California
+/*
+ * Copyright (c) 2014-2022, Regents of the University of California
  *
  * NAC library is free software: you can redistribute it and/or modify it under the
  * terms of the GNU Lesser General Public License as published by the Free Software
@@ -19,8 +19,7 @@
 
 #include "common.hpp"
 
-namespace ndn {
-namespace nac {
+namespace ndn::nac {
 
 Name
 convertKekNameToKdkPrefix(const Name& kekName, const ErrorCallback& onFailure)
@@ -47,10 +46,9 @@
   }
 
   auto kekName = ckDataName.getSubName(ckName.size() + 1);
-  return std::make_tuple(convertKekNameToKdkPrefix(kekName, onFailure),
-                         kekName.getPrefix(-2),
-                         kekName.getPrefix(-2).append("KEY").append(kekName.get(-1)));
+  return {convertKekNameToKdkPrefix(kekName, onFailure),
+          kekName.getPrefix(-2),
+          kekName.getPrefix(-2).append("KEY").append(kekName.get(-1))};
 }
 
-} // namespace nac
-} // namespace ndn
+} // namespace ndn::nac