Use more C++17 features

Mainly structured bindings, inline variables, and class template
argument deduction, plus many more smaller things.

Change-Id: I810d17e0adb470426e4e30c898e03b3140ad052f
diff --git a/tests/daemon/face/lp-reliability.t.cpp b/tests/daemon/face/lp-reliability.t.cpp
index 526708f..0d891e0 100644
--- a/tests/daemon/face/lp-reliability.t.cpp
+++ b/tests/daemon/face/lp-reliability.t.cpp
@@ -140,8 +140,7 @@
   getPktNum(const lp::Packet& pkt)
   {
     BOOST_REQUIRE(pkt.has<lp::FragmentField>());
-    ndn::Buffer::const_iterator begin, end;
-    std::tie(begin, end) = pkt.get<lp::FragmentField>();
+    auto [begin, end] = pkt.get<lp::FragmentField>();
     if (std::distance(begin, end) < 4) {
       return 0;
     }