From 887faad3734aaf7a17e257cfc0c3fd218ffa1546 Mon Sep 17 00:00:00 2001
From: Raoul Gough <RaoulGough@yahoo.co.uk>
Date: Wed, 19 Nov 2003 15:02:10 +0000
Subject: [PATCH] Allow client replacement of value_traits, including less and
 equal_to members

[SVN r20860]
---
 .../suite/indexing/container_traits.hpp       | 39 ++++++++++++-------
 1 file changed, 25 insertions(+), 14 deletions(-)

diff --git a/include/boost/python/suite/indexing/container_traits.hpp b/include/boost/python/suite/indexing/container_traits.hpp
index d2254a48..f964f355 100755
--- a/include/boost/python/suite/indexing/container_traits.hpp
+++ b/include/boost/python/suite/indexing/container_traits.hpp
@@ -31,6 +31,7 @@
 #include <boost/type_traits/ice.hpp>
 
 #define ICE_AND(a, b) type_traits::ice_and<(a), (b)>::value
+// #undef'd later in this header
 
 namespace boost { namespace python { namespace indexing {
 #if BOOST_WORKAROUND (BOOST_MSVC, <= 1200)
@@ -52,7 +53,7 @@ namespace boost { namespace python { namespace indexing {
   // and iterator pairs
   /////////////////////////////////////////////////////////////////////////
 
-  template<typename Container>
+  template<typename Container, typename ValueTraits = detail::no_override>
   struct base_container_traits
     : public ::boost::python::indexing::iterator_traits <
         BOOST_DEDUCED_TYPENAME mpl::if_ <
@@ -71,8 +72,8 @@ namespace boost { namespace python { namespace indexing {
       >::type
     > base_type;
 
-    BOOST_STATIC_CONSTANT (bool,   is_mutable
-                           = ! boost::is_const<Container>::value);
+    BOOST_STATIC_CONSTANT (
+        bool, is_mutable = ! boost::is_const<Container>::value);
 
   public:
     typedef Container container;
@@ -91,13 +92,19 @@ namespace boost { namespace python { namespace indexing {
     typedef typename BOOST_PYTHON_INDEXING_CALL_TRAITS <index_type>::param_type
         index_param;
 
-    typedef value_traits<typename base_type::value_type> value_traits_;
+    // Allow client code to replace the default value traits via our
+    // second (optional) template parameter
+    typedef value_traits<typename base_type::value_type> default_value_traits;
 
-    BOOST_STATIC_CONSTANT (bool, has_mutable_ref
-                           = ICE_AND (base_type::has_mutable_ref, is_mutable));
+    typedef typename detail::maybe_override <
+        default_value_traits, ValueTraits>::type value_traits_;
 
-    BOOST_STATIC_CONSTANT (bool, has_find
-                           = value_traits_::equality_comparable);
+    BOOST_STATIC_CONSTANT (
+        bool, has_mutable_ref
+        = ICE_AND (base_type::has_mutable_ref, is_mutable));
+
+    BOOST_STATIC_CONSTANT (
+        bool, has_find = value_traits_::equality_comparable);
 
     // Assume the worst for everything else
     BOOST_STATIC_CONSTANT (bool, has_insert    = false);
@@ -118,10 +125,11 @@ namespace boost { namespace python { namespace indexing {
   // at least these requirements
   /////////////////////////////////////////////////////////////////////////
 
-  template<typename Container>
-  struct default_container_traits : public base_container_traits<Container>
+  template<typename Container, typename ValueTraits = detail::no_override>
+  struct default_container_traits
+    : public base_container_traits<Container, ValueTraits>
   {
-    typedef default_container_traits<Container> self_type;
+    typedef default_container_traits<Container, ValueTraits> self_type;
     BOOST_STATIC_CONSTANT (bool, has_insert = self_type::is_mutable);
     BOOST_STATIC_CONSTANT (bool, has_erase  = self_type::is_mutable);
   };
@@ -130,14 +138,17 @@ namespace boost { namespace python { namespace indexing {
   // Sequences (list, deque, vector)
   /////////////////////////////////////////////////////////////////////////
 
-  template<typename Container>
-  struct default_sequence_traits : public default_container_traits<Container>
+  template<typename Container, typename ValueTraits = detail::no_override>
+  struct default_sequence_traits
+    : public default_container_traits<Container, ValueTraits>
   {
-    typedef default_sequence_traits<Container> self_type;
+    typedef default_sequence_traits<Container, ValueTraits> self_type;
     BOOST_STATIC_CONSTANT (bool, has_pop_back  = self_type::is_mutable);
     BOOST_STATIC_CONSTANT (bool, has_push_back = self_type::is_mutable);
   };
 
 } } }
 
+#undef ICE_AND
+
 #endif // BOOST_PYTHON_INDEXING_CONTAINER_SUITE_HPP