From a369e3c8c53e3cc7bcef55936d68e6c8b8c9a660 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ion=20Gazta=C3=B1aga?= <igaztanaga@gmail.com>
Date: Sun, 4 Jan 2015 02:29:15 +0100
Subject: [PATCH] Avoid instantiating iterator tags to allow iterators that
 define iterator_categories with forward declared tags.

---
 bench/detail/varray.hpp                     | 19 ++++++++++---------
 include/boost/container/deque.hpp           | 11 ++++++-----
 include/boost/container/detail/iterator.hpp |  2 ++
 3 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/bench/detail/varray.hpp b/bench/detail/varray.hpp
index a1d1e8c..a1489f8 100644
--- a/bench/detail/varray.hpp
+++ b/bench/detail/varray.hpp
@@ -878,9 +878,7 @@ public:
     template <typename Iterator>
     iterator insert(iterator position, Iterator first, Iterator last)
     {
-        typedef typename boost::container::iterator_traits<Iterator>::iterator_category category;
-        this->insert_dispatch(position, first, last, category());
-
+        this->insert_dispatch(position, first, last);
         return position;
     }
 
@@ -961,8 +959,7 @@ public:
     template <typename Iterator>
     void assign(Iterator first, Iterator last)
     {
-        typedef typename boost::container::iterator_traits<Iterator>::iterator_category category;
-        this->assign_dispatch(first, last, category());                            // may throw
+        this->assign_dispatch(first, last);                            // may throw
     }
 
     //! @pre <tt>count <= capacity()</tt>
@@ -1698,7 +1695,8 @@ private:
     // @par Complexity
     //   Linear O(N).
     template <typename Iterator>
-    void insert_dispatch(iterator position, Iterator first, Iterator last, std::random_access_iterator_tag)
+    typename iterator_enable_if_tag<Iterator, std::random_access_iterator_tag>::type
+       insert_dispatch(iterator position, Iterator first, Iterator last)
     {
         errh::check_iterator_end_eq(*this, position);
 
@@ -1725,7 +1723,8 @@ private:
     // @par Complexity
     //   Linear O(N).
     template <typename Iterator, typename Category>
-    void insert_dispatch(iterator position, Iterator first, Iterator last, Category const& /*not_random_access*/)
+    typename iterator_disable_if_tag<Iterator, std::random_access_iterator_tag>::type
+        insert_dispatch(iterator position, Iterator first, Iterator last)
     {
         errh::check_iterator_end_eq(*this, position);
 
@@ -1791,7 +1790,8 @@ private:
     // @par Complexity
     //   Linear O(N).
     template <typename Iterator>
-    void assign_dispatch(Iterator first, Iterator last, std::random_access_iterator_tag const& /*not_random_access*/)
+    typename iterator_enable_if_tag<Iterator, std::random_access_iterator_tag>::type
+       assign_dispatch(Iterator first, Iterator last)
     {
         namespace sv = varray_detail;
 
@@ -1818,7 +1818,8 @@ private:
     // @par Complexity
     //   Linear O(N).
     template <typename Iterator, typename Category>
-    void assign_dispatch(Iterator first, Iterator last, Category const& /*not_random_access*/)
+    typename iterator_disable_if_tag<Iterator, std::random_access_iterator_tag>::type
+       assign_dispatch(Iterator first, Iterator last)
     {
         namespace sv = varray_detail;
 
diff --git a/include/boost/container/deque.hpp b/include/boost/container/deque.hpp
index 3383a21..38cd613 100644
--- a/include/boost/container/deque.hpp
+++ b/include/boost/container/deque.hpp
@@ -605,8 +605,7 @@ class deque : protected deque_base<Allocator>
       )
       : Base(a)
    {
-      typedef typename boost::container::iterator_traits<InIt>::iterator_category ItCat;
-      this->priv_range_initialize(first, last, ItCat());
+      this->priv_range_initialize(first, last);
    }
 
 #if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
@@ -620,7 +619,7 @@ class deque : protected deque_base<Allocator>
    deque(std::initializer_list<value_type> il, const allocator_type& a = allocator_type())
       : Base(a)
    {
-      this->priv_range_initialize(il.begin(), il.end(), std::input_iterator_tag());
+      this->priv_range_initialize(il.begin(), il.end());
    }
 #endif
 
@@ -1951,7 +1950,8 @@ class deque : protected deque_base<Allocator>
    }
 
    template <class InIt>
-   void priv_range_initialize(InIt first, InIt last, std::input_iterator_tag)
+   typename iterator_enable_if_tag<InIt, std::input_iterator_tag>::type
+      priv_range_initialize(InIt first, InIt last)
    {
       this->priv_initialize_map(0);
       BOOST_TRY {
@@ -1966,7 +1966,8 @@ class deque : protected deque_base<Allocator>
    }
 
    template <class FwdIt>
-   void priv_range_initialize(FwdIt first, FwdIt last, std::forward_iterator_tag)
+   typename iterator_disable_if_tag<FwdIt, std::input_iterator_tag>::type
+      priv_range_initialize(FwdIt first, FwdIt last)
    {
       size_type n = 0;
       n = boost::container::iterator_distance(first, last);
diff --git a/include/boost/container/detail/iterator.hpp b/include/boost/container/detail/iterator.hpp
index c1ef787..d7053c8 100644
--- a/include/boost/container/detail/iterator.hpp
+++ b/include/boost/container/detail/iterator.hpp
@@ -26,6 +26,8 @@ using ::boost::intrusive::iterator_traits;
 using ::boost::intrusive::iterator_distance;
 using ::boost::intrusive::iterator_advance;
 using ::boost::intrusive::iterator;
+using ::boost::intrusive::iterator_enable_if_tag;
+using ::boost::intrusive::iterator_disable_if_tag;
 
 }  //namespace container {
 }  //namespace boost {