From 224d63be588d325298d40addb99929deffd9c6b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philipp=20M=C3=B6ller?= <bootsarehax@gmail.com>
Date: Mon, 29 Jun 2015 13:03:48 +0200
Subject: [PATCH] On GCC 4.4 with C++0x enabled, ADL + next is unreliable

This is a combination of two bugs: the call to next should pick up
CGAL::next to begin with and even if it didn't iterator_traits should
arguably be SFINAE friendly. See
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40497

We fix this by fully qualifying the call on the affected compiler. To
make this work we have to partially break the dependency between
CGAL/boost/graph/iterator.h and CGAL/boost/graph/graph_traits_Surface_mesh.h
---
 .../boost/graph/graph_traits_Surface_mesh.h   | 16 +++++--
 BGL/include/CGAL/boost/graph/iterator.h       | 42 ++++++++++++++-----
 2 files changed, 43 insertions(+), 15 deletions(-)

diff --git a/BGL/include/CGAL/boost/graph/graph_traits_Surface_mesh.h b/BGL/include/CGAL/boost/graph/graph_traits_Surface_mesh.h
index aa4e388f9b4..9d44f2987c2 100644
--- a/BGL/include/CGAL/boost/graph/graph_traits_Surface_mesh.h
+++ b/BGL/include/CGAL/boost/graph/graph_traits_Surface_mesh.h
@@ -26,11 +26,21 @@
 #include <boost/iterator/transform_iterator.hpp>
 
 #include <CGAL/boost/graph/properties_Surface_mesh.h>
-#include <CGAL/boost/graph/iterator.h>
+// ATTN: <CGAL/boost/graph/iterator.h> is included at the end of this
+// file, because we need to fix some calls in that file instead of
+// using ADL on broken compilers, hence those calls need to declared
+// before that.
 
 #include <CGAL/Surface_mesh.h>
 
+namespace CGAL {
 
+template<typename Graph>
+class In_edge_iterator;
+template<typename Graph>
+class Out_edge_iterator;
+
+}
 
 namespace boost {
 
@@ -532,8 +542,6 @@ bool is_valid(CGAL::Surface_mesh<P>& sm, bool verbose = false)
 
 } // namespace CGAL
 
-
-
-
+#include <CGAL/boost/graph/iterator.h>
 
 #endif // CGAL_BOOST_GRAPH_TRAITS_SURFACE_MESH_H
diff --git a/BGL/include/CGAL/boost/graph/iterator.h b/BGL/include/CGAL/boost/graph/iterator.h
index 61eacb193aa..e794fcc0a66 100644
--- a/BGL/include/CGAL/boost/graph/iterator.h
+++ b/BGL/include/CGAL/boost/graph/iterator.h
@@ -20,8 +20,6 @@
 #ifndef CGAL_BGL_ITERATORS_H
 #define CGAL_BGL_ITERATORS_H
 
-#include <stdexcept>
-
 #include <boost/graph/graph_traits.hpp>
 #include <boost/iterator/iterator_adaptor.hpp>
 
@@ -181,6 +179,28 @@ struct Opposite_face {
     return face(opposite(h,*g),*g);
   }
 };
+
+// With gcc 4.4 and std=c++0x do not use ADL to find next/prev.
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40497
+template<typename A, typename Mesh>
+A adl_next(A a, const Mesh& m) {
+#if defined(__GXX_EXPERIMENTAL_CXX0X__) &&  __GNUC__ == 4 && __GNUC_MINOR__ == 4
+  return CGAL::next(a, m);
+#else
+  return next(a, m);
+#endif
+}
+
+template<typename A, typename Mesh>
+A adl_prev(A a, const Mesh& m) {
+#if defined(__GXX_EXPERIMENTAL_CXX0X__) &&  __GNUC__ == 4 && __GNUC_MINOR__ == 4
+  return CGAL::prev(a, m);
+#else
+  return prev(a, m);
+#endif
+}
+
+
 } // namespace internal
 /// \endcond
 
@@ -258,7 +278,7 @@ public:
   }
 
   Self& operator++() {
-    pos = next(opposite(pos,*g),*g);
+    pos = internal::adl_next(opposite(pos,*g),*g);
     if ( pos == anchor)
       ++winding;
     return *this;
@@ -271,7 +291,7 @@ public:
   Self& operator--() {
     if ( pos == anchor)
       --winding;
-    pos = opposite(prev(pos,*g),*g);
+    pos = opposite(internal::adl_prev(pos,*g),*g);
     return *this;
   }
   Self  operator--(int) {
@@ -358,7 +378,7 @@ public:
   }
 
   Self& operator++() {
-    pos = opposite(next(pos,*g),*g);
+    pos = opposite(internal::adl_next(pos,*g),*g);
     if ( pos == anchor)
       ++winding;
     return *this;
@@ -371,7 +391,7 @@ public:
   Self& operator--() {
     if ( pos == anchor)
       --winding;
-    pos = prev(opposite(pos,*g),*g);
+    pos = internal::adl_prev(opposite(pos,*g),*g);
     return *this;
   }
   Self  operator--(int) {
@@ -464,7 +484,7 @@ public:
     if ( pos == anchor)
       --winding;
   
-    pos = prev(pos,*g);
+    pos = internal::adl_prev(pos,*g);
     return *this;
   }
 
@@ -684,7 +704,7 @@ public:
   Self& operator++() 
   {
     CGAL_assertion(g != NULL);
-    pos = opposite(next(pos,*g),*g);
+    pos = opposite(internal::adl_next(pos,*g),*g);
     return *this;
   }
 
@@ -699,7 +719,7 @@ public:
   Self& operator--() 
   {
     CGAL_assertion(g != NULL);
-    pos = prev(opposite(pos,*g),*g);
+    pos = internal::adl_prev(opposite(pos,*g),*g);
     return *this;
   }
 
@@ -779,7 +799,7 @@ public:
   Self& operator++() 
   {
     CGAL_assertion(g != NULL);
-    pos = next(pos,*g);
+    pos = internal::adl_next(pos,*g);
     return *this;
   }
 
@@ -794,7 +814,7 @@ public:
   Self& operator--() 
   {
     CGAL_assertion(g != NULL);
-    pos = prev(pos,*g);
+    pos = internal::adl_prev(pos,*g);
     return *this;
   }