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/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)