From b63c8214d73dab3d2c9c92a9bfbd43b6de5f49a7 Mon Sep 17 00:00:00 2001
From: Joel de Guzman <djowel@gmail.com>
Date: Mon, 14 May 2012 00:37:21 +0000
Subject: [PATCH] Patches from Nathan Ridge using SFINAE to disable the Fusion
 algorithms for non-{Fusion sequence} types

[SVN r78463]
---
 .../boost/fusion/algorithm/auxiliary/copy.hpp | 13 ++++++-
 .../fusion/algorithm/iteration/accumulate.hpp | 16 +++++++--
 .../algorithm/iteration/accumulate_fwd.hpp    | 15 ++++++--
 .../fusion/algorithm/iteration/for_each.hpp   | 16 +++++++--
 .../algorithm/iteration/for_each_fwd.hpp      | 17 +++++++--
 .../boost/fusion/algorithm/query/count.hpp    |  9 ++++-
 .../boost/fusion/algorithm/query/count_if.hpp |  9 ++++-
 .../fusion/algorithm/transformation/erase.hpp | 35 ++++++++++++++++---
 .../algorithm/transformation/insert.hpp       | 10 ++++--
 .../algorithm/transformation/push_back.hpp    |  9 ++++-
 .../algorithm/transformation/push_front.hpp   |  9 ++++-
 .../algorithm/transformation/replace.hpp      |  9 ++++-
 .../algorithm/transformation/replace_if.hpp   |  8 ++++-
 .../algorithm/transformation/reverse.hpp      |  9 ++++-
 .../detail/segmented_iterator_range.hpp       | 14 ++++++--
 15 files changed, 174 insertions(+), 24 deletions(-)

diff --git a/include/boost/fusion/algorithm/auxiliary/copy.hpp b/include/boost/fusion/algorithm/auxiliary/copy.hpp
index 2720627c..fd866468 100644
--- a/include/boost/fusion/algorithm/auxiliary/copy.hpp
+++ b/include/boost/fusion/algorithm/auxiliary/copy.hpp
@@ -11,8 +11,11 @@
 #include <boost/fusion/sequence/intrinsic/end.hpp>
 #include <boost/fusion/sequence/intrinsic/size.hpp>
 #include <boost/fusion/sequence/comparison/detail/equal_to.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
 #include <boost/config.hpp>
 #include <boost/static_assert.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/type_traits/ice.hpp>
 
 #if defined (BOOST_MSVC)
 #  pragma warning(push)
@@ -54,7 +57,15 @@ namespace boost { namespace fusion
     }
 
     template <typename Seq1, typename Seq2>
-    inline void
+    inline
+    typename
+        enable_if_c<
+            type_traits::ice_and<
+                traits::is_sequence<Seq1>::value
+              , traits::is_sequence<Seq2>::value
+            >::value,
+            void
+        >::type
     copy(Seq1 const& src, Seq2& dest)
     {
         BOOST_STATIC_ASSERT(
diff --git a/include/boost/fusion/algorithm/iteration/accumulate.hpp b/include/boost/fusion/algorithm/iteration/accumulate.hpp
index a8d6a357..4b676dea 100644
--- a/include/boost/fusion/algorithm/iteration/accumulate.hpp
+++ b/include/boost/fusion/algorithm/iteration/accumulate.hpp
@@ -9,6 +9,8 @@
 
 #include <boost/fusion/algorithm/iteration/accumulate_fwd.hpp>
 #include <boost/fusion/algorithm/iteration/fold.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
 
 namespace boost { namespace fusion
 {
@@ -23,14 +25,24 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename State, typename F>
-    inline typename result_of::accumulate<Sequence, State const, F>::type
+    inline 
+    typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::accumulate<Sequence, State const, F>
+        >::type
     accumulate(Sequence& seq, State const& state, F f)
     {
         return fusion::fold(seq, state, f);
     }
 
     template <typename Sequence, typename State, typename F>
-    inline typename result_of::accumulate<Sequence const, State const, F>::type
+    inline 
+    typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::accumulate<Sequence const, State const, F>
+        >::type
     accumulate(Sequence const& seq, State const& state, F f)
     {
         return fusion::fold(seq, state, f);
diff --git a/include/boost/fusion/algorithm/iteration/accumulate_fwd.hpp b/include/boost/fusion/algorithm/iteration/accumulate_fwd.hpp
index 9c0bd115..a4ca316c 100644
--- a/include/boost/fusion/algorithm/iteration/accumulate_fwd.hpp
+++ b/include/boost/fusion/algorithm/iteration/accumulate_fwd.hpp
@@ -7,6 +7,9 @@
 #if !defined(BOOST_FUSION_ACCUMULATE_FWD_HPP_INCLUDED)
 #define BOOST_FUSION_ACCUMULATE_FWD_HPP_INCLUDED
 
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
+
 namespace boost { namespace fusion
 {
     namespace result_of
@@ -16,11 +19,19 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename State, typename F>
-    typename result_of::accumulate<Sequence, State const, F>::type
+    typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::accumulate<Sequence, State const, F>
+        >::type
     accumulate(Sequence& seq, State const& state, F f);
 
     template <typename Sequence, typename State, typename F>
-    typename result_of::accumulate<Sequence const, State const, F>::type
+    typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::accumulate<Sequence const, State const, F>
+        >::type
     accumulate(Sequence const& seq, State const& state, F f);
 }}
 
diff --git a/include/boost/fusion/algorithm/iteration/for_each.hpp b/include/boost/fusion/algorithm/iteration/for_each.hpp
index ab8b8f0e..17cde34a 100644
--- a/include/boost/fusion/algorithm/iteration/for_each.hpp
+++ b/include/boost/fusion/algorithm/iteration/for_each.hpp
@@ -11,6 +11,8 @@
 #include <boost/fusion/algorithm/iteration/detail/for_each.hpp>
 #include <boost/fusion/algorithm/iteration/detail/segmented_for_each.hpp>
 #include <boost/fusion/support/is_segmented.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
 
 namespace boost { namespace fusion
 {
@@ -24,14 +26,24 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename F>
-    inline void
+    inline
+    typename
+        enable_if<
+            traits::is_sequence<Sequence>
+          , void
+        >::type
     for_each(Sequence& seq, F const& f)
     {
         detail::for_each(seq, f, typename traits::is_segmented<Sequence>::type());
     }
 
     template <typename Sequence, typename F>
-    inline void
+    inline
+    typename
+        enable_if<
+            traits::is_sequence<Sequence>
+          , void
+        >::type
     for_each(Sequence const& seq, F const& f)
     {
         detail::for_each(seq, f, typename traits::is_segmented<Sequence>::type());
diff --git a/include/boost/fusion/algorithm/iteration/for_each_fwd.hpp b/include/boost/fusion/algorithm/iteration/for_each_fwd.hpp
index 544915d9..b757873e 100644
--- a/include/boost/fusion/algorithm/iteration/for_each_fwd.hpp
+++ b/include/boost/fusion/algorithm/iteration/for_each_fwd.hpp
@@ -7,6 +7,9 @@
 #if !defined(BOOST_FUSION_FOR_EACH_FWD_HPP_INCLUDED)
 #define BOOST_FUSION_FOR_EACH_FWD_HPP_INCLUDED
 
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
+
 namespace boost { namespace fusion
 {
     namespace result_of
@@ -16,11 +19,21 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename F>
-    void
+    inline
+    typename
+        enable_if<
+            traits::is_sequence<Sequence>
+          , void
+        >::type
     for_each(Sequence& seq, F const& f);
 
     template <typename Sequence, typename F>
-    void
+    inline
+    typename
+        enable_if<
+            traits::is_sequence<Sequence>
+          , void
+        >::type
     for_each(Sequence const& seq, F const& f);
 }}
 
diff --git a/include/boost/fusion/algorithm/query/count.hpp b/include/boost/fusion/algorithm/query/count.hpp
index ade58671..04887163 100644
--- a/include/boost/fusion/algorithm/query/count.hpp
+++ b/include/boost/fusion/algorithm/query/count.hpp
@@ -10,6 +10,8 @@
 
 #include <boost/fusion/algorithm/query/count_if.hpp>
 #include <boost/fusion/algorithm/query/detail/count.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
 
 namespace boost { namespace fusion
 {
@@ -23,7 +25,12 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename T>
-    inline int
+    inline
+    typename
+        enable_if<
+            traits::is_sequence<Sequence>
+          , int
+        >::type
     count(Sequence const& seq, T const& x)
     {
         detail::count_compare<T> f(x);
diff --git a/include/boost/fusion/algorithm/query/count_if.hpp b/include/boost/fusion/algorithm/query/count_if.hpp
index 51112cf0..79297973 100644
--- a/include/boost/fusion/algorithm/query/count_if.hpp
+++ b/include/boost/fusion/algorithm/query/count_if.hpp
@@ -10,6 +10,8 @@
 
 #include <boost/fusion/algorithm/query/detail/count_if.hpp>
 #include <boost/fusion/support/category_of.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
 
 namespace boost { namespace fusion
 {
@@ -23,7 +25,12 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename F>
-    inline int
+    inline 
+    typename
+        enable_if<
+            traits::is_sequence<Sequence>
+          , int
+        >::type
     count_if(Sequence const& seq, F f)
     {
         return detail::count_if(
diff --git a/include/boost/fusion/algorithm/transformation/erase.hpp b/include/boost/fusion/algorithm/transformation/erase.hpp
index 304ed4c5..6ad737fd 100644
--- a/include/boost/fusion/algorithm/transformation/erase.hpp
+++ b/include/boost/fusion/algorithm/transformation/erase.hpp
@@ -16,6 +16,9 @@
 #include <boost/fusion/sequence/intrinsic/begin.hpp>
 #include <boost/fusion/sequence/intrinsic/end.hpp>
 #include <boost/fusion/adapted/mpl/mpl_iterator.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/mpl/if.hpp>
 
 namespace boost { namespace fusion
 {
@@ -53,18 +56,38 @@ namespace boost { namespace fusion
             }
         };
 
+        struct use_default;
+        
+        template <class T, class Default>
+        struct fusion_default_help
+          : mpl::if_<
+                is_same<T, use_default>
+              , Default
+              , T
+            >
+        {
+        };
+        
         template <
             typename Sequence
           , typename First
-          , typename Last = typename compute_erase_last<Sequence, First>::type>
+          , typename Last = use_default>
         struct erase
         {
             typedef typename result_of::begin<Sequence>::type seq_first_type;
             typedef typename result_of::end<Sequence>::type seq_last_type;
             BOOST_STATIC_ASSERT((!result_of::equal_to<seq_first_type, seq_last_type>::value));
 
-            typedef typename convert_iterator<First>::type first_type;
-            typedef typename convert_iterator<Last>::type last_type;
+            typedef First FirstType;
+            typedef typename 
+                fusion_default_help<
+                    Last 
+                  , typename compute_erase_last<Sequence, First>::type
+                >::type
+            LastType;
+            
+            typedef typename convert_iterator<FirstType>::type first_type;
+            typedef typename convert_iterator<LastType>::type last_type;
             typedef iterator_range<seq_first_type, first_type> left_type;
             typedef iterator_range<last_type, seq_last_type> right_type;
             typedef joint_view<left_type, right_type> type;
@@ -72,7 +95,11 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename First>
-    typename result_of::erase<Sequence const, First>::type
+    typename 
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , typename result_of::erase<Sequence const, First> 
+        >::type
     erase(Sequence const& seq, First const& first)
     {
         typedef result_of::erase<Sequence const, First> result_of;
diff --git a/include/boost/fusion/algorithm/transformation/insert.hpp b/include/boost/fusion/algorithm/transformation/insert.hpp
index ac5bca38..2052fc01 100644
--- a/include/boost/fusion/algorithm/transformation/insert.hpp
+++ b/include/boost/fusion/algorithm/transformation/insert.hpp
@@ -16,6 +16,8 @@
 #include <boost/fusion/sequence/intrinsic/begin.hpp>
 #include <boost/fusion/sequence/intrinsic/end.hpp>
 #include <boost/fusion/adapted/mpl/mpl_iterator.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
 
 namespace boost { namespace fusion
 {
@@ -38,8 +40,12 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename Position, typename T>
-    inline typename result_of::insert<
-        Sequence const, Position, T>::type
+    inline 
+    typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::insert<Sequence const, Position, T>
+        >::type
     insert(Sequence const& seq, Position const& pos, T const& x)
     {
         typedef result_of::insert<
diff --git a/include/boost/fusion/algorithm/transformation/push_back.hpp b/include/boost/fusion/algorithm/transformation/push_back.hpp
index 00a01a80..9afe538a 100644
--- a/include/boost/fusion/algorithm/transformation/push_back.hpp
+++ b/include/boost/fusion/algorithm/transformation/push_back.hpp
@@ -10,6 +10,8 @@
 #include <boost/fusion/support/detail/as_fusion_element.hpp>
 #include <boost/fusion/view/joint_view/joint_view.hpp>
 #include <boost/fusion/view/single_view/single_view.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
 
 namespace boost { namespace fusion
 {
@@ -24,7 +26,12 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename T>
-    inline typename result_of::push_back<Sequence const, T>::type
+    inline 
+    typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::push_back<Sequence const, T>
+        >::type
     push_back(Sequence const& seq, T const& x)
     {
         typedef typename result_of::push_back<Sequence const, T> push_back;
diff --git a/include/boost/fusion/algorithm/transformation/push_front.hpp b/include/boost/fusion/algorithm/transformation/push_front.hpp
index d08ad279..abe7faad 100644
--- a/include/boost/fusion/algorithm/transformation/push_front.hpp
+++ b/include/boost/fusion/algorithm/transformation/push_front.hpp
@@ -10,6 +10,8 @@
 #include <boost/fusion/support/detail/as_fusion_element.hpp>
 #include <boost/fusion/view/joint_view/joint_view.hpp>
 #include <boost/fusion/view/single_view/single_view.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
 
 namespace boost { namespace fusion
 {
@@ -24,7 +26,12 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename T>
-    inline typename result_of::push_front<Sequence const, T>::type
+    inline 
+    typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::push_front<Sequence const, T>
+        >::type
     push_front(Sequence const& seq, T const& x)
     {
         typedef typename result_of::push_front<Sequence const, T> push_front;
diff --git a/include/boost/fusion/algorithm/transformation/replace.hpp b/include/boost/fusion/algorithm/transformation/replace.hpp
index bfe186e5..a92e6e37 100644
--- a/include/boost/fusion/algorithm/transformation/replace.hpp
+++ b/include/boost/fusion/algorithm/transformation/replace.hpp
@@ -9,6 +9,8 @@
 
 #include <boost/fusion/view/transform_view/transform_view.hpp>
 #include <boost/fusion/algorithm/transformation/detail/replace.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
 
 namespace boost { namespace fusion
 {
@@ -22,7 +24,12 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename T>
-    inline typename result_of::replace<Sequence const, T>::type
+    inline 
+    typename
+        enable_if<
+            traits::is_sequence<Sequence>
+          , typename result_of::replace<Sequence const, T>::type
+        >::type
     replace(Sequence const& seq, T const& old_value, T const& new_value)
     {
         typedef typename result_of::replace<Sequence const, T>::type result;
diff --git a/include/boost/fusion/algorithm/transformation/replace_if.hpp b/include/boost/fusion/algorithm/transformation/replace_if.hpp
index 29913436..39b9009a 100644
--- a/include/boost/fusion/algorithm/transformation/replace_if.hpp
+++ b/include/boost/fusion/algorithm/transformation/replace_if.hpp
@@ -9,6 +9,7 @@
 
 #include <boost/fusion/view/transform_view/transform_view.hpp>
 #include <boost/fusion/algorithm/transformation/detail/replace_if.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
 #include <boost/utility/enable_if.hpp>
 #include <boost/type_traits/is_same.hpp>
 
@@ -24,7 +25,12 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename F, typename T>
-    inline typename result_of::replace_if<Sequence const, F, T>::type
+    inline 
+    typename 
+        enable_if<
+            traits::is_sequence<Sequence>
+          , typename result_of::replace_if<Sequence const, F, T>::type
+        >::type
     replace_if(Sequence const& seq, F pred, T const& new_value)
     {
         typedef typename result_of::replace_if<Sequence const, F, T>::type result;
diff --git a/include/boost/fusion/algorithm/transformation/reverse.hpp b/include/boost/fusion/algorithm/transformation/reverse.hpp
index 23c4fe65..923b90fc 100644
--- a/include/boost/fusion/algorithm/transformation/reverse.hpp
+++ b/include/boost/fusion/algorithm/transformation/reverse.hpp
@@ -8,6 +8,8 @@
 #define FUSION_REVERSE_07212005_1230
 
 #include <boost/fusion/view/reverse_view/reverse_view.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
 
 namespace boost { namespace fusion
 {
@@ -21,7 +23,12 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence>
-    inline reverse_view<Sequence const>
+    inline 
+    typename
+        enable_if<
+            traits::is_sequence<Sequence>
+          , reverse_view<Sequence const>
+        >::type
     reverse(Sequence const& view)
     {
         return reverse_view<Sequence const>(view);
diff --git a/include/boost/fusion/view/iterator_range/detail/segmented_iterator_range.hpp b/include/boost/fusion/view/iterator_range/detail/segmented_iterator_range.hpp
index 489d9553..9bf459c4 100644
--- a/include/boost/fusion/view/iterator_range/detail/segmented_iterator_range.hpp
+++ b/include/boost/fusion/view/iterator_range/detail/segmented_iterator_range.hpp
@@ -21,6 +21,8 @@
 #include <boost/fusion/iterator/equal_to.hpp>
 #include <boost/fusion/container/list/detail/reverse_cons.hpp>
 #include <boost/fusion/iterator/detail/segment_sequence.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/utility/enable_if.hpp>
 
 //  Invariants:
 //  - Each segmented iterator has a stack
@@ -45,11 +47,19 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence, typename T>
-    typename result_of::push_back<Sequence const, T>::type
+    typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::push_back<Sequence const, T>
+        >::type
     push_back(Sequence const& seq, T const& x);
 
     template <typename Sequence, typename T>
-    typename result_of::push_front<Sequence const, T>::type
+    typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::push_front<Sequence const, T>
+        >::type
     push_front(Sequence const& seq, T const& x);
 }}