Index: libcfa/src/virtual_dtor.hfa
===================================================================
--- libcfa/src/virtual_dtor.hfa	(revision 1e940de005fb6cb7e356132c758058f238a0b528)
+++ libcfa/src/virtual_dtor.hfa	(revision 1f10959b24503b04405e0b0b4143b2c7f494bbef)
@@ -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 &);