diff --git a/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.cpp b/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.cpp
index ca54132..7aff618 100644
--- a/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.cpp
+++ b/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.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,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -28,14 +28,14 @@
 namespace nfd {
 namespace rib {
 
-optional<ReadvertiseAction>
+std::optional<ReadvertiseAction>
 ClientToNlsrReadvertisePolicy::handleNewRoute(const RibRouteRef& ribRoute) const
 {
   if (ribRoute.route->origin == ndn::nfd::ROUTE_ORIGIN_CLIENT) {
     return ReadvertiseAction{ribRoute.entry->getName(), ndn::security::SigningInfo()};
   }
   else {
-    return nullopt;
+    return std::nullopt;
   }
 }
 
diff --git a/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.hpp b/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.hpp
index b1c5e29..c0d5837 100644
--- a/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.hpp
+++ b/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -41,7 +41,7 @@
    *  If the route origin is "client" (typically from auto prefix propagation), readvertise it
    *  using the default signing identity.
    */
-  optional<ReadvertiseAction>
+  std::optional<ReadvertiseAction>
   handleNewRoute(const RibRouteRef& ribRoute) const override;
 
   time::milliseconds
diff --git a/daemon/rib/readvertise/host-to-gateway-readvertise-policy.cpp b/daemon/rib/readvertise/host-to-gateway-readvertise-policy.cpp
index 9ee7985..89f11fd 100644
--- a/daemon/rib/readvertise/host-to-gateway-readvertise-policy.cpp
+++ b/daemon/rib/readvertise/host-to-gateway-readvertise-policy.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -44,13 +44,13 @@
   m_refreshInterval = interval ? time::seconds(*interval) : DEFAULT_REFRESH_INTERVAL;
 }
 
-optional<ReadvertiseAction>
+std::optional<ReadvertiseAction>
 HostToGatewayReadvertisePolicy::handleNewRoute(const RibRouteRef& ribRoute) const
 {
   auto ribEntryName = ribRoute.entry->getName();
   if (scope_prefix::LOCALHOST.isPrefixOf(ribEntryName) ||
       ribEntryName == RibManager::LOCALHOP_TOP_PREFIX) {
-    return nullopt;
+    return std::nullopt;
   }
 
   // find out the shortest identity whose name is a prefix of the RIB entry name
@@ -73,12 +73,10 @@
     }
   }
 
-  if (isFound) {
-    return ReadvertiseAction{prefixToAdvertise, ndn::security::signingByIdentity(signingIdentity)};
+  if (!isFound) {
+    return std::nullopt;
   }
-  else {
-    return nullopt;
-  }
+  return ReadvertiseAction{prefixToAdvertise, ndn::security::signingByIdentity(signingIdentity)};
 }
 
 time::milliseconds
diff --git a/daemon/rib/readvertise/host-to-gateway-readvertise-policy.hpp b/daemon/rib/readvertise/host-to-gateway-readvertise-policy.hpp
index 325fc80..ac2491d 100644
--- a/daemon/rib/readvertise/host-to-gateway-readvertise-policy.hpp
+++ b/daemon/rib/readvertise/host-to-gateway-readvertise-policy.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -43,7 +43,7 @@
                                  const ConfigSection& section);
 
 public:
-  optional<ReadvertiseAction>
+  std::optional<ReadvertiseAction>
   handleNewRoute(const RibRouteRef& ribRoute) const override;
 
   time::milliseconds
diff --git a/daemon/rib/readvertise/readvertise-policy.hpp b/daemon/rib/readvertise/readvertise-policy.hpp
index 99deccb..da22139 100644
--- a/daemon/rib/readvertise/readvertise-policy.hpp
+++ b/daemon/rib/readvertise/readvertise-policy.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -51,7 +51,7 @@
 
   /** \brief decide whether to readvertise a route, and what prefix to readvertise
    */
-  virtual optional<ReadvertiseAction>
+  virtual std::optional<ReadvertiseAction>
   handleNewRoute(const RibRouteRef& ribRoute) const = 0;
 
   /** \return how often readvertisements made by this policy should be refreshed.
diff --git a/daemon/rib/readvertise/readvertise.cpp b/daemon/rib/readvertise/readvertise.cpp
index 2f16795..addad72 100644
--- a/daemon/rib/readvertise/readvertise.cpp
+++ b/daemon/rib/readvertise/readvertise.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -67,7 +67,7 @@
 void
 Readvertise::afterAddRoute(const RibRouteRef& ribRoute)
 {
-  optional<ReadvertiseAction> action = m_policy->handleNewRoute(ribRoute);
+  std::optional<ReadvertiseAction> action = m_policy->handleNewRoute(ribRoute);
   if (!action) {
     NFD_LOG_DEBUG("add-route " << ribRoute.entry->getName() << '(' << ribRoute.route->faceId <<
                   ',' << ribRoute.route->origin << ") not-readvertising");
diff --git a/daemon/rib/route.hpp b/daemon/rib/route.hpp
index 18df250..9b0bead 100644
--- a/daemon/rib/route.hpp
+++ b/daemon/rib/route.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2021,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -82,13 +82,13 @@
   ndn::nfd::RouteOrigin origin = ndn::nfd::ROUTE_ORIGIN_APP;
   uint64_t cost = 0;
   std::underlying_type_t<ndn::nfd::RouteFlags> flags = ndn::nfd::ROUTE_FLAGS_NONE;
-  optional<time::steady_clock::time_point> expires;
+  std::optional<time::steady_clock::time_point> expires;
 
   /** \brief The prefix announcement that caused the creation of this route.
    *
    *  This is nullopt if this route is not created by a prefix announcement.
    */
-  optional<ndn::PrefixAnnouncement> announcement;
+  std::optional<ndn::PrefixAnnouncement> announcement;
 
   /** \brief Expiration time of the prefix announcement.
    *