Index: src/work/klao/debug.h
===================================================================
--- src/work/klao/debug.h	(revision 619)
+++ src/work/klao/debug.h	(revision 680)
@@ -9,4 +9,8 @@
 namespace hugo {
 
+  //! Debug mode for testing/debugging
+
+  //! Use this debug mode if you want exhaustive range and consistency checks.
+  //! It also produces verbose debug messages.
   struct DebugOn {
     //! Example: check whether the edges added to a path are adjacent
@@ -23,4 +27,9 @@
   };
 
+  //! Debug mode for turning off debug aids.
+
+  //! This debud mode switches off all range and consistency checks,
+  //! as well as the debug messages.
+  //!
   struct DebugOff {
     static const bool consistensy_check = false;
@@ -31,6 +40,14 @@
 
 #ifdef DEBUG
+  //! The default debug mode.
+
+  //! The default debug mode.
+  //!
   typedef DebugOn DefaultDebugMode;
 #else
+  //! The default debug mode. 
+
+  //! The default debug mode. 
+  //!
   typedef DebugOff DefaultDebugMode;
 #endif