Make assignment_typet into an enum class

Author: reuk

src/goto-symex/build_goto_trace.cpp

@@ -191,7 +191,9 @@ void build_goto_trace(
           symex_target_equationt::assignment_typet::PHI ||
         SSA_step.assignment_type==
           symex_target_equationt::assignment_typet::GUARD))
+    {
       continue;
+    }
 
     goto_tracet::stepst &steps=time_map[current_time];
     steps.push_back(goto_trace_stept());

src/goto-symex/symex_target.h

@@ -56,7 +56,12 @@ class symex_targett
 
   enum class assignment_typet
   {
-    STATE, HIDDEN, VISIBLE_ACTUAL_PARAMETER, HIDDEN_ACTUAL_PARAMETER, PHI, GUARD
+    STATE,
+    HIDDEN,
+    VISIBLE_ACTUAL_PARAMETER,
+    HIDDEN_ACTUAL_PARAMETER,
+    PHI,
+    GUARD,
   };
 
   // read event

src/goto-symex/symex_target_equation.cpp

@@ -647,17 +647,23 @@ void symex_target_equationt::SSA_stept::output(
     switch(assignment_type)
     {
     case assignment_typet::HIDDEN:
-      out << "HIDDEN"; break;
+      out << "HIDDEN";
+      break;
     case assignment_typet::STATE:
-      out << "STATE"; break;
+      out << "STATE";
+      break;
     case assignment_typet::VISIBLE_ACTUAL_PARAMETER:
-      out << "VISIBLE_ACTUAL_PARAMETER"; break;
+      out << "VISIBLE_ACTUAL_PARAMETER";
+      break;
     case assignment_typet::HIDDEN_ACTUAL_PARAMETER:
-      out << "HIDDEN_ACTUAL_PARAMETER"; break;
+      out << "HIDDEN_ACTUAL_PARAMETER";
+      break;
     case assignment_typet::PHI:
-      out << "PHI"; break;
+      out << "PHI";
+      break;
     case assignment_typet::GUARD:
-      out << "GUARD"; break;
+      out << "GUARD";
+      break;
     default:
       {
       }