C++: support enum class

Author: tautschnig

regression/cpp/enum_class1/main.cpp

@@ -14,4 +14,7 @@ int main()
 {
   Color1 c;
   c=Color1::red;
+
+  Color2 c2;
+  c2 = red;
 }

regression/cpp/enum_class1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.cpp
 -std=c++11
 ^EXIT=0$

src/cpp/cpp_typecheck_enum_type.cpp

@@ -193,6 +193,12 @@ void cpp_typecheckt::typecheck_enum_type(typet &type)
       cpp_scopes.put_into_scope(*new_symbol, dest_scope);
 
     scope_identifier.id_class=cpp_idt::id_classt::CLASS;
+    scope_identifier.is_scope = true;
+
+    cpp_save_scopet save_scope(cpp_scopes);
+
+    if(new_symbol->type.get_bool(ID_C_class))
+      cpp_scopes.go_to(scope_identifier);
 
     typecheck_enum_body(*new_symbol);
   }

src/cpp/parse.cpp

@@ -4039,7 +4039,6 @@ bool Parser::rEnumSpec(typet &spec)
   #endif
 
   cpp_tokent tk;
-  // bool is_enum_class=false;
 
   if(lex.get_token(tk)!=TOK_ENUM)
     return false;
@@ -4053,7 +4052,7 @@ bool Parser::rEnumSpec(typet &spec)
   if(lex.LookAhead(0)==TOK_CLASS)
   {
     lex.get_token(tk);
-    // is_enum_class=true;
+    spec.set(ID_C_class, true);
   }
 
   if(lex.LookAhead(0)!='{' &&