Index: libcfa/src/virtual_dtor.hfa
===================================================================
--- libcfa/src/virtual_dtor.hfa	(revision 1fbf481de7b6f658d4627f71c96ffba349954e16)
+++ libcfa/src/virtual_dtor.hfa	(revision a1f0cb667245ca06f92ac43da8ee0b87f481ab7a)
@@ -1,3 +1,5 @@
-// inline this structure to have a virtual dtor.
+#pragma once
+
+// inline virtual_dtor to have a virtual dtor.
 // when using this, delete() is also virtual and will be called on the right address
 // using free() directly on polymorphic types may result in unaligned memory deallocation
@@ -8,5 +10,4 @@
 //     given struct A { inline virtual_dtor; } and struct B { inline virtual_dtor; }
 //     struct C { inline A; inline B; } will result in undefined behaviour
-
 struct virtual_dtor {
     void (*__virtual_dtor_ptr)(virtual_dtor &);