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/fw/unsolicited-data-policy.t.cpp b/tests/daemon/fw/unsolicited-data-policy.t.cpp
index 5c8c8ad..77722c7 100644
--- a/tests/daemon/fw/unsolicited-data-policy.t.cpp
+++ b/tests/daemon/fw/unsolicited-data-policy.t.cpp
@@ -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,
@@ -95,8 +95,8 @@
 struct FaceScopePolicyTest
 {
   using PolicyType = Policy;
-  using ShouldAdmitLocal = std::integral_constant<bool, shouldAdmitLocal>;
-  using ShouldAdmitNonLocal = std::integral_constant<bool, shouldAdmitNonLocal>;
+  using ShouldAdmitLocal = std::bool_constant<shouldAdmitLocal>;
+  using ShouldAdmitNonLocal = std::bool_constant<shouldAdmitNonLocal>;
 };
 
 using FaceScopePolicyTests = boost::mpl::vector<