Migrate to C++17 and refactor

Change-Id: I53407266939258990a1c3a9363c3ebe9ea113fd2
diff --git a/src/redirection/redirection-policy.cpp b/src/redirection/redirection-policy.cpp
index 88aef3e..9ecda9a 100644
--- a/src/redirection/redirection-policy.cpp
+++ b/src/redirection/redirection-policy.cpp
@@ -25,7 +25,7 @@
 std::unique_ptr<RedirectionPolicy>
 RedirectionPolicy::createPolicyFunc(const std::string& policyType, const std::string& format)
 {
-  PolicyFactory& factory = getFactory();
+  auto& factory = getFactory();
   auto i = factory.find(policyType);
   return i == factory.end() ? nullptr : i->second(format);
 }