common: stop importing std::{bind,ref,cref} into namespace ndn

And reduce the usage of std::bind() throughout the codebase.
C++14 lambdas are easier to understand for humans and more
likely to be optimized by the compiler.

Change-Id: Ia59fad34539710f8801c52914896ce426fb7e538
diff --git a/tests/unit/face.t.cpp b/tests/unit/face.t.cpp
index f7c6132..eaab9b6 100644
--- a/tests/unit/face.t.cpp
+++ b/tests/unit/face.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -35,6 +35,7 @@
 namespace tests {
 
 using ndn::util::DummyClientFace;
+using std::bind;
 
 struct WantPrefixRegReply;
 struct NoPrefixRegReply;
diff --git a/tests/unit/mgmt/dispatcher.t.cpp b/tests/unit/mgmt/dispatcher.t.cpp
index a6054c2..7827516 100644
--- a/tests/unit/mgmt/dispatcher.t.cpp
+++ b/tests/unit/mgmt/dispatcher.t.cpp
@@ -31,6 +31,7 @@
 namespace tests {
 
 using namespace ndn::tests;
+using std::bind;
 
 class DispatcherFixture : public IoKeyChainFixture
 {
diff --git a/tests/unit/mgmt/nfd/controller-fixture.hpp b/tests/unit/mgmt/nfd/controller-fixture.hpp
index 77c7620..764ff41 100644
--- a/tests/unit/mgmt/nfd/controller-fixture.hpp
+++ b/tests/unit/mgmt/nfd/controller-fixture.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -42,8 +42,8 @@
     : face(m_io, m_keyChain)
     , m_validator(true)
     , controller(face, m_keyChain, m_validator)
-    , commandFailCallback(bind(&ControllerFixture::recordCommandFail, this, _1))
-    , datasetFailCallback(bind(&ControllerFixture::recordDatasetFail, this, _1, _2))
+    , commandFailCallback([this] (const auto& resp) { failCodes.push_back(resp.getCode()); })
+    , datasetFailCallback([this] (auto code, const auto&) { failCodes.push_back(code); })
   {
     m_keyChain.setDefaultIdentity(m_keyChain.createIdentity("/localhost/ControllerFixture"));
   }
@@ -59,19 +59,6 @@
     m_validator.getPolicy().setResult(shouldAccept);
   }
 
-private:
-  void
-  recordCommandFail(const ControlResponse& response)
-  {
-    failCodes.push_back(response.getCode());
-  }
-
-  void
-  recordDatasetFail(uint32_t code, const std::string& reason)
-  {
-    failCodes.push_back(code);
-  }
-
 protected:
   ndn::util::DummyClientFace face;
   DummyValidator m_validator;
diff --git a/tests/unit/mgmt/nfd/controller.t.cpp b/tests/unit/mgmt/nfd/controller.t.cpp
index b0a5838..83deb23 100644
--- a/tests/unit/mgmt/nfd/controller.t.cpp
+++ b/tests/unit/mgmt/nfd/controller.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -37,11 +37,6 @@
 class CommandFixture : public ControllerFixture
 {
 protected:
-  CommandFixture()
-    : succeedCallback(bind(&CommandFixture::succeed, this, _1))
-  {
-  }
-
   void
   respond(const ControlResponse& responsePayload)
   {
@@ -51,15 +46,10 @@
     this->advanceClocks(1_ms);
   }
 
-private:
-  void
-  succeed(const ControlParameters& parameters)
-  {
-    succeeds.push_back(parameters);
-  }
-
 protected:
-  Controller::CommandSucceedCallback succeedCallback;
+  Controller::CommandSucceedCallback succeedCallback = [this] (const auto& params) {
+    succeeds.push_back(params);
+  };
   std::vector<ControlParameters> succeeds;
 };
 
diff --git a/tests/unit/mgmt/status-dataset-context.t.cpp b/tests/unit/mgmt/status-dataset-context.t.cpp
index 58c8382..6d1e0b9 100644
--- a/tests/unit/mgmt/status-dataset-context.t.cpp
+++ b/tests/unit/mgmt/status-dataset-context.t.cpp
@@ -229,13 +229,7 @@
 class AbnormalStateTestFixture
 {
 protected:
-  AbnormalStateTestFixture()
-    : context(Interest("/abnormal-state"), bind([]{}), bind([]{}))
-  {
-  }
-
-protected:
-  StatusDatasetContext context;
+  StatusDatasetContext context{Interest("/abnormal-state"), [] (auto&&...) {}, [] (auto&&...) {}};
 };
 
 BOOST_FIXTURE_TEST_SUITE(AbnormalState, AbnormalStateTestFixture)
diff --git a/tests/unit/net/dns.t.cpp b/tests/unit/net/dns.t.cpp
index db834c0..374eeea 100644
--- a/tests/unit/net/dns.t.cpp
+++ b/tests/unit/net/dns.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2018 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -36,12 +36,6 @@
 class DnsFixture
 {
 public:
-  DnsFixture()
-    : m_nFailures(0)
-    , m_nSuccesses(0)
-  {
-  }
-
   void
   onSuccess(const IpAddress& resolvedAddress,
             const IpAddress& expectedAddress,
@@ -51,7 +45,7 @@
     ++m_nSuccesses;
 
     if (!isValid) {
-      BOOST_FAIL("Resolved to " + resolvedAddress.to_string() + ", but should have failed");
+      BOOST_ERROR("Resolved to " + resolvedAddress.to_string() + ", but should have failed");
     }
 
     BOOST_CHECK_EQUAL(resolvedAddress.is_v4(), expectedAddress.is_v4());
@@ -64,20 +58,15 @@
   }
 
   void
-  onFailure(bool isValid)
+  onFailure(bool shouldFail)
   {
     ++m_nFailures;
-
-    if (!isValid) {
-      BOOST_FAIL("Resolution should not have failed");
-    }
-
-    BOOST_CHECK_MESSAGE(true, "Resolution failed as expected");
+    BOOST_CHECK_MESSAGE(shouldFail, "Resolution should not have failed");
   }
 
 protected:
-  uint32_t m_nFailures;
-  uint32_t m_nSuccesses;
+  int m_nFailures = 0;
+  int m_nSuccesses = 0;
   boost::asio::io_service m_ioService;
 };
 
@@ -89,8 +78,8 @@
   SKIP_IF_IP_UNAVAILABLE();
 
   asyncResolve("nothost.nothost.nothost.arpa",
-               bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v4()), false, false),
-               bind(&DnsFixture::onFailure, this, true),
+               std::bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v4()), false, false),
+               [this] (auto&&...) { onFailure(true); },
                m_ioService); // should fail
 
   m_ioService.run();
@@ -103,9 +92,9 @@
   SKIP_IF_IPV4_UNAVAILABLE();
 
   asyncResolve("192.0.2.1",
-               bind(&DnsFixture::onSuccess, this, _1,
-                    IpAddress(address_v4::from_string("192.0.2.1")), true, true),
-               bind(&DnsFixture::onFailure, this, false),
+               std::bind(&DnsFixture::onSuccess, this, _1,
+                         IpAddress(address_v4::from_string("192.0.2.1")), true, true),
+               [this] (auto&&...) { onFailure(false); },
                m_ioService);
 
   m_ioService.run();
@@ -118,15 +107,15 @@
   SKIP_IF_IPV6_UNAVAILABLE();
 
   asyncResolve("ipv6.google.com", // only IPv6 address should be available
-               bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v6()), true, false),
-               bind(&DnsFixture::onFailure, this, false),
+               std::bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v6()), true, false),
+               [this] (auto&&...) { onFailure(false); },
                m_ioService);
 
   asyncResolve("2001:db8:3f9:0:3025:ccc5:eeeb:86d3",
-               bind(&DnsFixture::onSuccess, this, _1,
-                    IpAddress(address_v6::from_string("2001:db8:3f9:0:3025:ccc5:eeeb:86d3")),
-                    true, true),
-               bind(&DnsFixture::onFailure, this, false),
+               std::bind(&DnsFixture::onSuccess, this, _1,
+                         IpAddress(address_v6::from_string("2001:db8:3f9:0:3025:ccc5:eeeb:86d3")),
+                         true, true),
+               [this] (auto&&...) { onFailure(false); },
                m_ioService);
 
   m_ioService.run();
@@ -140,28 +129,28 @@
   SKIP_IF_IPV6_UNAVAILABLE();
 
   asyncResolve("www.named-data.net",
-               bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v4()), true, false),
-               bind(&DnsFixture::onFailure, this, false),
+               std::bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v4()), true, false),
+               [this] (auto&&...) { onFailure(false); },
                m_ioService, Ipv4Only());
 
   asyncResolve("a.root-servers.net",
-               bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v4()), true, false),
-               bind(&DnsFixture::onFailure, this, false),
+               std::bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v4()), true, false),
+               [this] (auto&&...) { onFailure(false); },
                m_ioService, Ipv4Only()); // request IPv4 address
 
   asyncResolve("a.root-servers.net",
-               bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v6()), true, false),
-               bind(&DnsFixture::onFailure, this, false),
+               std::bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v6()), true, false),
+               [this] (auto&&...) { onFailure(false); },
                m_ioService, Ipv6Only()); // request IPv6 address
 
   asyncResolve("ipv6.google.com", // only IPv6 address should be available
-               bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v6()), true, false),
-               bind(&DnsFixture::onFailure, this, false),
+               std::bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v6()), true, false),
+               [this] (auto&&...) { onFailure(false); },
                m_ioService, Ipv6Only());
 
   asyncResolve("ipv6.google.com", // only IPv6 address should be available
-               bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v6()), false, false),
-               bind(&DnsFixture::onFailure, this, true),
+               std::bind(&DnsFixture::onSuccess, this, _1, IpAddress(address_v6()), false, false),
+               [this] (auto&&...) { onFailure(true); },
                m_ioService, Ipv4Only()); // should fail
 
   m_ioService.run();
diff --git a/tests/unit/net/face-uri.t.cpp b/tests/unit/net/face-uri.t.cpp
index c8f7d16..76af381 100644
--- a/tests/unit/net/face-uri.t.cpp
+++ b/tests/unit/net/face-uri.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California,
+ * Copyright (c) 2013-2021 Regents of the University of California,
  *                         Arizona Board of Regents,
  *                         Colorado State University,
  *                         University Pierre & Marie Curie, Sorbonne University,
@@ -69,8 +69,8 @@
     auto tc = make_shared<CanonizeTestCase>(request, shouldSucceed, expectedUri);
 
     FaceUri uri(request);
-    uri.canonize(bind(&CanonizeFixture::onCanonizeSuccess, this, tc, _1),
-                 bind(&CanonizeFixture::onCanonizeFailure, this, tc, _1),
+    uri.canonize(std::bind(&CanonizeFixture::onCanonizeSuccess, this, tc, _1),
+                 std::bind(&CanonizeFixture::onCanonizeFailure, this, tc, _1),
                  m_io, 10_s);
   }
 
diff --git a/tests/unit/security/certificate-fetcher-from-network.t.cpp b/tests/unit/security/certificate-fetcher-from-network.t.cpp
index caf941a..36a1ae9 100644
--- a/tests/unit/security/certificate-fetcher-from-network.t.cpp
+++ b/tests/unit/security/certificate-fetcher-from-network.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -65,7 +65,7 @@
     interest.setCanBePrefix(false);
     m_keyChain.sign(interest, signingByIdentity(subSubIdentity));
 
-    processInterest = bind(&CertificateFetcherFromNetworkFixture<Response>::makeResponse, this, _1);
+    processInterest = [this] (const Interest& i) { makeResponse(i); };
   }
 
   void
diff --git a/tests/unit/security/validator-fixture.cpp b/tests/unit/security/validator-fixture.cpp
index 8bb4713..7a7ee14 100644
--- a/tests/unit/security/validator-fixture.cpp
+++ b/tests/unit/security/validator-fixture.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -46,7 +46,7 @@
 {
   util::signal::ScopedConnection conn = face.onSendInterest.connect([this] (const Interest& interest) {
     if (processInterest) {
-      m_io.post(bind(processInterest, interest));
+      m_io.post([=] { processInterest(interest); });
     }
   });
   advanceClocks(s_mockPeriod, s_mockTimes);
diff --git a/tests/unit/security/validator-null.t.cpp b/tests/unit/security/validator-null.t.cpp
index 9d04cb8..8fc5a5e 100644
--- a/tests/unit/security/validator-null.t.cpp
+++ b/tests/unit/security/validator-null.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -28,6 +28,8 @@
 namespace security {
 namespace tests {
 
+using std::bind;
+
 BOOST_AUTO_TEST_SUITE(Security)
 BOOST_FIXTURE_TEST_SUITE(TestValidatorNull, ndn::tests::KeyChainFixture)
 
diff --git a/tests/unit/util/notification-subscriber.t.cpp b/tests/unit/util/notification-subscriber.t.cpp
index d8f9dfd..3936e9e 100644
--- a/tests/unit/util/notification-subscriber.t.cpp
+++ b/tests/unit/util/notification-subscriber.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2020 Regents of the University of California,
+ * Copyright (c) 2014-2021 Regents of the University of California,
  *                         Arizona Board of Regents,
  *                         Colorado State University,
  *                         University Pierre & Marie Curie, Sorbonne University,
@@ -74,45 +74,16 @@
   void
   deliverNack(const Interest& interest, const lp::NackReason& reason)
   {
-    lp::Nack nack = makeNack(interest, reason);
-    subscriberFace.receive(nack);
-  }
-
-  void
-  afterNotification(const SimpleNotification& notification)
-  {
-    lastNotification = notification;
-  }
-
-  void
-  afterNack(const lp::Nack& nack)
-  {
-    lastNack = nack;
-  }
-
-  void
-  afterTimeout()
-  {
-    hasTimeout = true;
-  }
-
-  void
-  afterDecodeError(const Data& data)
-  {
-    lastDecodeErrorData = data;
+    subscriberFace.receive(makeNack(interest, reason));
   }
 
   void
   connectHandlers()
   {
-    notificationConn = subscriber.onNotification.connect(
-      bind(&NotificationSubscriberFixture::afterNotification, this, _1));
-    nackConn = subscriber.onNack.connect(
-      bind(&NotificationSubscriberFixture::afterNack, this, _1));
-    subscriber.onTimeout.connect(
-      bind(&NotificationSubscriberFixture::afterTimeout, this));
-    subscriber.onDecodeError.connect(
-      bind(&NotificationSubscriberFixture::afterDecodeError, this, _1));
+    notificationConn = subscriber.onNotification.connect([this] (const auto& n) { lastNotification = n; });
+    nackConn = subscriber.onNack.connect([this] (const auto& nack) { lastNack = nack; });
+    subscriber.onTimeout.connect([this] { hasTimeout = true; });
+    subscriber.onDecodeError.connect([this] (const auto& data) { lastDecodeErrorData = data; });
   }
 
   void
diff --git a/tests/unit/util/scheduler.t.cpp b/tests/unit/util/scheduler.t.cpp
index 12f018a..1040b92 100644
--- a/tests/unit/util/scheduler.t.cpp
+++ b/tests/unit/util/scheduler.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -109,7 +109,7 @@
   void
   reschedule()
   {
-    EventId eventId = scheduler.schedule(100_ms, bind(&SelfRescheduleFixture::reschedule, this));
+    EventId eventId = scheduler.schedule(100_ms, [this] { reschedule(); });
     selfEventId.cancel();
     selfEventId = eventId;
 
@@ -125,7 +125,7 @@
     selfEventId.cancel();
 
     if (count < 5)  {
-      selfEventId = scheduler.schedule(100_ms, bind(&SelfRescheduleFixture::reschedule2, this));
+      selfEventId = scheduler.schedule(100_ms, [this] { reschedule2(); });
       count++;
     }
   }
@@ -150,21 +150,21 @@
 
 BOOST_FIXTURE_TEST_CASE(Reschedule, SelfRescheduleFixture)
 {
-  selfEventId = scheduler.schedule(0_s, bind(&SelfRescheduleFixture::reschedule, this));
+  selfEventId = scheduler.schedule(0_s, [this] { reschedule(); });
   BOOST_REQUIRE_NO_THROW(advanceClocks(50_ms, 1000_ms));
   BOOST_CHECK_EQUAL(count, 5);
 }
 
 BOOST_FIXTURE_TEST_CASE(Reschedule2, SelfRescheduleFixture)
 {
-  selfEventId = scheduler.schedule(0_s, bind(&SelfRescheduleFixture::reschedule2, this));
+  selfEventId = scheduler.schedule(0_s, [this] { reschedule2(); });
   BOOST_REQUIRE_NO_THROW(advanceClocks(50_ms, 1000_ms));
   BOOST_CHECK_EQUAL(count, 5);
 }
 
 BOOST_FIXTURE_TEST_CASE(Reschedule3, SelfRescheduleFixture)
 {
-  selfEventId = scheduler.schedule(0_s, bind(&SelfRescheduleFixture::reschedule3, this));
+  selfEventId = scheduler.schedule(0_s, [this] { reschedule3(); });
   BOOST_REQUIRE_NO_THROW(advanceClocks(50_ms, 1000_ms));
   BOOST_CHECK_EQUAL(count, 6);
 }
diff --git a/tests/unit/util/segment-fetcher.t.cpp b/tests/unit/util/segment-fetcher.t.cpp
index c58c1f9..55247fe 100644
--- a/tests/unit/util/segment-fetcher.t.cpp
+++ b/tests/unit/util/segment-fetcher.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -36,6 +36,7 @@
 namespace tests {
 
 using namespace ndn::tests;
+using std::bind;
 
 class SegmentFetcherFixture : public IoKeyChainFixture
 {