build: switch to C++17

Change-Id: Id6217b5c993f3e4726e89773128b565e5f136bb6
diff --git a/tests/chunks/pipeline-interests-fixed.t.cpp b/tests/chunks/pipeline-interests-fixed.t.cpp
index 872fe4e..b4f9723 100644
--- a/tests/chunks/pipeline-interests-fixed.t.cpp
+++ b/tests/chunks/pipeline-interests-fixed.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2016-2020, Regents of the University of California,
+ * Copyright (c) 2016-2022, Regents of the University of California,
  *                          Colorado State University,
  *                          University Pierre & Marie Curie, Sorbonne University.
  *
@@ -29,9 +29,7 @@
 
 #include "pipeline-interests-fixture.hpp"
 
-namespace ndn {
-namespace chunks {
-namespace tests {
+namespace ndn::chunks::tests {
 
 class PipelineInterestFixedFixture : public PipelineInterestsFixture
 {
@@ -298,6 +296,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestPipelineInterests
 BOOST_AUTO_TEST_SUITE_END() // Chunks
 
-} // namespace tests
-} // namespace chunks
-} // namespace ndn
+} // namespace ndn::chunks::tests