From bcd55626efca835d3b2aa038daf1ec5d9eb29f64 Mon Sep 17 00:00:00 2001
From: Emil Tin <emil.tin@tmf.kk.dk>
Date: Wed, 20 Aug 2014 11:37:47 +0200
Subject: [PATCH] make accessors const, add comments

---
 DataStructures/TravelMode.h |  2 +-
 Extractor/ExtractionWay.h   | 11 ++++++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/DataStructures/TravelMode.h b/DataStructures/TravelMode.h
index 0cead0d65..7ccc24d21 100644
--- a/DataStructures/TravelMode.h
+++ b/DataStructures/TravelMode.h
@@ -28,7 +28,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #ifndef TRAVEL_MODE_H
 #define TRAVEL_MODE_H
 
-typedef unsigned char TravelMode;
+using TravelMode = unsigned char;
 static const TravelMode TRAVEL_MODE_INACCESSIBLE = 0;
 static const TravelMode TRAVEL_MODE_DEFAULT = 1;
 
diff --git a/Extractor/ExtractionWay.h b/Extractor/ExtractionWay.h
index 6a3acc697..36c138f89 100644
--- a/Extractor/ExtractionWay.h
+++ b/Extractor/ExtractionWay.h
@@ -62,6 +62,9 @@ struct ExtractionWay
       bidirectional,
       opposite };
     
+    // These accessor methods exists to support the depreciated "way.direction" access
+    // in LUA. Since the direction attribute was removed from ExtractionWay, the 
+    // accessors translate to/from the mode attributes.
     inline void set_direction(const Directions m)
     {
         if (Directions::oneway == m)
@@ -81,7 +84,7 @@ struct ExtractionWay
         }
     }
 
-    inline const Directions get_direction()
+    inline const Directions get_direction() const
     {
         if (TRAVEL_MODE_INACCESSIBLE != forward_travel_mode && TRAVEL_MODE_INACCESSIBLE != backward_travel_mode)
         {
@@ -101,10 +104,12 @@ struct ExtractionWay
         }
     }
 
+    // These accessors exists because it's not possible to take the address of a bitfield,
+    // and LUA therefore cannot read/write the mode attributes directly.
     inline void set_forward_mode(const TravelMode m) { forward_travel_mode = m; }
-    inline const TravelMode get_forward_mode() { return forward_travel_mode; }
+    inline const TravelMode get_forward_mode() const { return forward_travel_mode; }
     inline void set_backward_mode(const TravelMode m) { backward_travel_mode = m; }
-    inline const TravelMode get_backward_mode() { return backward_travel_mode; }
+    inline const TravelMode get_backward_mode() const { return backward_travel_mode; }
 
     unsigned id;
     unsigned nameID;