Move is_template_scope to parent as it holds the id_class member

Author: tautschnig

src/cpp/cpp_id.h

@@ -70,6 +70,11 @@ class cpp_idt
     return id_class==id_classt::TYPEDEF;
   }
 
+  bool is_template_scope() const
+  {
+    return id_class==id_classt::TEMPLATE_SCOPE;
+  }
+
   irep_idt identifier, base_name;
 
   // if it is a member or method, what class is it in?

src/cpp/cpp_scope.h

@@ -81,11 +81,6 @@ class cpp_scopet:public cpp_idt
            id_class==id_classt::NAMESPACE;
   }
 
-  bool is_template_scope() const
-  {
-    return id_class==id_classt::TEMPLATE_SCOPE;
-  }
-
   cpp_scopet &get_parent() const
   {
     return static_cast<cpp_scopet &>(cpp_idt::get_parent());

src/cpp/cpp_typecheck_template.cpp

@@ -159,8 +159,10 @@ void cpp_typecheckt::typecheck_class_template(
         previous_declaration.template_type());
     }
 
-    assert(cpp_scopes.id_map[symbol_name]->id_class ==
-           cpp_idt::id_classt::TEMPLATE_SCOPE);
+    INVARIANT(
+      cpp_scopes.id_map[symbol_name]->is_template_scope(),
+      "symbol should be in template scope");
+
     return;
   }
 
@@ -198,8 +200,10 @@ void cpp_typecheckt::typecheck_class_template(
 
   // link the template symbol with the template scope
   cpp_scopes.id_map[symbol_name]=&template_scope;
-  assert(cpp_scopes.id_map[symbol_name]->id_class ==
-         cpp_idt::id_classt::TEMPLATE_SCOPE);
+
+  INVARIANT(
+    cpp_scopes.id_map[symbol_name]->is_template_scope(),
+    "symbol should be in template scope");
 }
 
 /// typecheck function templates
@@ -301,8 +305,10 @@ void cpp_typecheckt::typecheck_function_template(
             id2string(new_symbol->base_name);
 
   // link the template symbol with the template scope
-  assert(template_scope.id_class==cpp_idt::id_classt::TEMPLATE_SCOPE);
   cpp_scopes.id_map[symbol_name] = &template_scope;
+  INVARIANT(
+    template_scope.is_template_scope(),
+    "symbol should be in template scope");
 }
 
 /// typecheck class template members; these can be methods or static members