build: switch to C++17

Change-Id: Id6217b5c993f3e4726e89773128b565e5f136bb6
diff --git a/tests/chunks/pipeline-interests-cubic.t.cpp b/tests/chunks/pipeline-interests-cubic.t.cpp
index fc53343..9934d9f 100644
--- a/tests/chunks/pipeline-interests-cubic.t.cpp
+++ b/tests/chunks/pipeline-interests-cubic.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.
  *
@@ -29,17 +29,14 @@
 
 #include "pipeline-interests-fixture.hpp"
 
-namespace ndn {
-namespace chunks {
-namespace tests {
+namespace ndn::chunks::tests {
 
 using namespace ndn::tests;
 
 class PipelineInterestCubicFixture : public PipelineInterestsFixture
 {
-public:
+protected:
   PipelineInterestCubicFixture()
-    : rttEstimator(makeRttEstimatorOptions())
   {
     opt.isQuiet = true;
     createPipeline();
@@ -70,7 +67,7 @@
 
 protected:
   Options opt;
-  RttEstimatorWithStats rttEstimator;
+  RttEstimatorWithStats rttEstimator{makeRttEstimatorOptions()};
   PipelineInterestsCubic* pipeline;
   static constexpr double MARGIN = 0.001;
 };
@@ -562,6 +559,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestPipelineInterestsCubic
 BOOST_AUTO_TEST_SUITE_END() // Chunks
 
-} // namespace tests
-} // namespace chunks
-} // namespace ndn
+} // namespace ndn::chunks::tests