Fix build with latest ndn-cxx

Change-Id: I48f45eab3f3500c1a2174094c820642b1eb4962f
diff --git a/tests/clock-fixture.cpp b/tests/clock-fixture.cpp
index f138bda..daa0e6d 100644
--- a/tests/clock-fixture.cpp
+++ b/tests/clock-fixture.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  Regents of the University of California,
+ * Copyright (c) 2014-2024,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -28,8 +28,8 @@
 namespace ndn::tests {
 
 ClockFixture::ClockFixture()
-  : m_steadyClock(make_shared<time::UnitTestSteadyClock>())
-  , m_systemClock(make_shared<time::UnitTestSystemClock>())
+  : m_steadyClock(std::make_shared<time::UnitTestSteadyClock>())
+  , m_systemClock(std::make_shared<time::UnitTestSystemClock>())
 {
   time::setCustomClocks(m_steadyClock, m_systemClock);
 }
diff --git a/tests/clock-fixture.hpp b/tests/clock-fixture.hpp
index 27bf167..c329775 100644
--- a/tests/clock-fixture.hpp
+++ b/tests/clock-fixture.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  Regents of the University of California,
+ * Copyright (c) 2014-2024,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -78,8 +78,8 @@
   }
 
 protected:
-  shared_ptr<time::UnitTestSteadyClock> m_steadyClock;
-  shared_ptr<time::UnitTestSystemClock> m_systemClock;
+  std::shared_ptr<time::UnitTestSteadyClock> m_steadyClock;
+  std::shared_ptr<time::UnitTestSystemClock> m_systemClock;
 };
 
 } // namespace ndn::tests
diff --git a/tests/ping/server/ping-server.t.cpp b/tests/ping/server/ping-server.t.cpp
index 05a7d84..2efae0e 100644
--- a/tests/ping/server/ping-server.t.cpp
+++ b/tests/ping/server/ping-server.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2023,  Arizona Board of Regents.
+ * Copyright (c) 2014-2024,  Arizona Board of Regents.
  *
  * This file is part of ndn-tools (Named Data Networking Essential Tools).
  * See AUTHORS.md for complete list of ndn-tools authors and contributors.
@@ -37,7 +37,7 @@
   {
     Name name(pingOptions.prefix);
     name.append("ping")
-        .append(to_string(seq));
+        .append(std::to_string(seq));
 
     return Interest(name)
            .setMustBeFresh(true)