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/daemon/table/pit.hpp b/daemon/table/pit.hpp
index c998a4d..b44dce8 100644
--- a/daemon/table/pit.hpp
+++ b/daemon/table/pit.hpp
@@ -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,
@@ -99,7 +99,7 @@
   deleteInOutRecords(Entry* entry, const Face& face);
 
 public: // enumeration
-  typedef Iterator const_iterator;
+  using const_iterator = Iterator;
 
   /** \return an iterator to the beginning
    *  \note Iteration order is implementation-defined.