Refactor and modernize namespace declarations

Move all unit tests to namespace nfd::tests

Delete unused header core/algorithm.hpp

Change-Id: I5591f0c5f3bb5db67f8b45fae95471f8a555ca68
diff --git a/tests/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.t.cpp b/tests/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.t.cpp
index b804725..eab14e8 100644
--- a/tests/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.t.cpp
+++ b/tests/daemon/rib/readvertise/client-to-nlsr-readvertise-policy.t.cpp
@@ -28,11 +28,9 @@
 #include "tests/test-common.hpp"
 #include "tests/daemon/global-io-fixture.hpp"
 
-namespace nfd {
-namespace rib {
-namespace tests {
+namespace nfd::tests {
 
-using namespace nfd::tests;
+using namespace nfd::rib;
 
 BOOST_AUTO_TEST_SUITE(Readvertise)
 BOOST_FIXTURE_TEST_SUITE(TestClientToNlsrReadvertisePolicy, GlobalIoFixture)
@@ -72,6 +70,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestClientToNlsrReadvertisePolicy
 BOOST_AUTO_TEST_SUITE_END() // Readvertise
 
-} // namespace tests
-} // namespace rib
-} // namespace nfd
+} // namespace nfd::tests
diff --git a/tests/daemon/rib/readvertise/host-to-gateway-readvertise-policy.t.cpp b/tests/daemon/rib/readvertise/host-to-gateway-readvertise-policy.t.cpp
index c3682dd..df73058 100644
--- a/tests/daemon/rib/readvertise/host-to-gateway-readvertise-policy.t.cpp
+++ b/tests/daemon/rib/readvertise/host-to-gateway-readvertise-policy.t.cpp
@@ -29,11 +29,9 @@
 #include "tests/key-chain-fixture.hpp"
 #include "tests/daemon/global-io-fixture.hpp"
 
-namespace nfd {
-namespace rib {
-namespace tests {
+namespace nfd::tests {
 
-using namespace nfd::tests;
+using namespace nfd::rib;
 
 class HostToGatewayReadvertisePolicyFixture : public GlobalIoFixture, public KeyChainFixture
 {
@@ -109,6 +107,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestHostToGatewayReadvertisePolicy
 BOOST_AUTO_TEST_SUITE_END() // Readvertise
 
-} // namespace tests
-} // namespace rib
-} // namespace nfd
+} // namespace nfd::tests
diff --git a/tests/daemon/rib/readvertise/nfd-rib-readvertise-destination.t.cpp b/tests/daemon/rib/readvertise/nfd-rib-readvertise-destination.t.cpp
index 5a64bbe..36ca585 100644
--- a/tests/daemon/rib/readvertise/nfd-rib-readvertise-destination.t.cpp
+++ b/tests/daemon/rib/readvertise/nfd-rib-readvertise-destination.t.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,
@@ -32,11 +32,9 @@
 #include <ndn-cxx/security/signing-info.hpp>
 #include <ndn-cxx/util/dummy-client-face.hpp>
 
-namespace nfd {
-namespace rib {
-namespace tests {
+namespace nfd::tests {
 
-using namespace nfd::tests;
+using namespace nfd::rib;
 
 class NfdRibReadvertiseDestinationFixture : public GlobalIoTimeFixture, public KeyChainFixture
 {
@@ -251,6 +249,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestNfdRibReadvertiseDestination
 BOOST_AUTO_TEST_SUITE_END() // Readvertise
 
-} // namespace tests
-} // namespace rib
-} // namespace nfd
+} // namespace nfd::tests
diff --git a/tests/daemon/rib/readvertise/readvertise.t.cpp b/tests/daemon/rib/readvertise/readvertise.t.cpp
index ffcab71..6242dfc 100644
--- a/tests/daemon/rib/readvertise/readvertise.t.cpp
+++ b/tests/daemon/rib/readvertise/readvertise.t.cpp
@@ -34,11 +34,9 @@
 #include <boost/range/adaptor/transformed.hpp>
 #include <boost/range/algorithm/copy.hpp>
 
-namespace nfd {
-namespace rib {
-namespace tests {
+namespace nfd::tests {
 
-using namespace nfd::tests;
+using namespace nfd::rib;
 
 class DummyReadvertisePolicy : public ReadvertisePolicy
 {
@@ -300,6 +298,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestReadvertise
 BOOST_AUTO_TEST_SUITE_END() // Readvertise
 
-} // namespace tests
-} // namespace rib
-} // namespace nfd
+} // namespace nfd::tests