From 54b0fbc99a2d6f961e88403b077b4faadd67812e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Loriot?= <sloriot.ml@gmail.com>
Date: Mon, 14 Jun 2010 16:24:10 +0000
Subject: [PATCH] add helper functions tuple_size and tuple_element for
 CGAL::cpp0x:tuple This is defined in cpp0x and tr1 but not in boost: in case 
 boost::tuple is used, it relies on internal boost struct.

---
 STL_Extension/include/CGAL/tuple.h            | 13 ++++++++++++
 .../test/STL_Extension/test_stl_extension.cpp | 20 +++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/STL_Extension/include/CGAL/tuple.h b/STL_Extension/include/CGAL/tuple.h
index 627fb85c367..f8cd14b608a 100644
--- a/STL_Extension/include/CGAL/tuple.h
+++ b/STL_Extension/include/CGAL/tuple.h
@@ -42,16 +42,29 @@ using std::tuple;
 using std::make_tuple;
 using std::tie;
 using std::get;
+using std::tuple_size;
+using std::tuple_element;
 #elif !defined CGAL_CFG_NO_TR1_TUPLE
 using std::tr1::tuple;
 using std::tr1::make_tuple;
 using std::tr1::tie;
 using std::tr1::get;
+using std::tr1::tuple_size;
+using std::tr1::tuple_element;
 #else
 using boost::tuple;
 using boost::make_tuple;
 using boost::tie;
 using boost::get;
+  
+//tuple_size
+template <class T>
+struct tuple_size:public boost::tuples::length<T> {};
+  
+//tuple_element
+template <int N,class T>
+struct tuple_element: public boost::tuples::element<N,T>{};
+  
 #endif
 
 } // cpp0x
diff --git a/STL_Extension/test/STL_Extension/test_stl_extension.cpp b/STL_Extension/test/STL_Extension/test_stl_extension.cpp
index 3666d99fcc6..e4fd55710f4 100644
--- a/STL_Extension/test/STL_Extension/test_stl_extension.cpp
+++ b/STL_Extension/test/STL_Extension/test_stl_extension.cpp
@@ -44,6 +44,7 @@
 #include <CGAL/Circulator_project.h>
 #include <CGAL/Circulator_on_node.h>
 #include <CGAL/function_objects.h>
+#include <CGAL/tuple.h>
 
 using namespace CGAL;
 
@@ -8987,6 +8988,24 @@ void test_Quadruple()
   if (x2 == y2) x4.third = x3;
 }
 
+void test_tuple(){
+  typedef CGAL::cpp0x::tuple<> T0;
+  typedef CGAL::cpp0x::tuple<int,int> T1;
+  typedef CGAL::cpp0x::tuple<int,My_to_int,int,int> T2;
+  
+  
+  BOOST_STATIC_ASSERT( CGAL::cpp0x::tuple_size<T0>::value == 0 );
+  BOOST_STATIC_ASSERT( CGAL::cpp0x::tuple_size<T1>::value == 2 );
+  BOOST_STATIC_ASSERT( CGAL::cpp0x::tuple_size<T2>::value == 4 );
+  BOOST_STATIC_ASSERT( (boost::is_same<CGAL::cpp0x::tuple_element<1,T2>::type,My_to_int>::value) );  
+  
+  T1 t1=CGAL::cpp0x::make_tuple(1,2);
+  int i1=-1,i2=-1;
+  CGAL::cpp0x::tie(i1,i2)=t1;
+  CGAL_assertion( CGAL::cpp0x::get<0>(t1)==i1 );
+  CGAL_assertion( CGAL::cpp0x::get<1>(t1)==i2 );
+}
+
 void test_predecessor_successor()
 {
   std::vector<int> V;
@@ -9018,6 +9037,7 @@ int main() {
   test_Quadruple();
   test_predecessor_successor();
   clean_global_data();
+  test_tuple();
   return 0;
 }
 // EOF //