Use std::string_view in several APIs

Change-Id: I2c13b229162b247738cbf46d6bf71fc69d45816f
diff --git a/tests/unit/util/logging.t.cpp b/tests/unit/util/logging.t.cpp
index 821e11e..02da03a 100644
--- a/tests/unit/util/logging.t.cpp
+++ b/tests/unit/util/logging.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2022 Regents of the University of California.
+ * Copyright (c) 2013-2023 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -162,7 +162,7 @@
 NDN_LOG_MEMBER_INIT_SPECIALIZED((ClassTemplateWithLogger<int, double>), ndn.util.tests.Specialized1);
 NDN_LOG_MEMBER_INIT_SPECIALIZED((ClassTemplateWithLogger<int, std::string>), ndn.util.tests.Specialized2);
 
-const time::microseconds LOG_SYSTIME(1468108800311239LL);
+constexpr time::microseconds LOG_SYSTIME{1468108800311239LL};
 const std::string LOG_SYSTIME_STR("1468108800.311239");
 
 class LoggingFixture : public ndn::tests::ClockFixture
@@ -177,7 +177,7 @@
     Logging::setDestination(os, true);
   }
 
-  ~LoggingFixture()
+  ~LoggingFixture() override
   {
     Logging::get().setLevelImpl(m_oldEnabledLevel);
     Logging::setDestination(m_oldDestination);