From f39fdf871bfaa6d1ef78c0a903083bade49b44cb Mon Sep 17 00:00:00 2001
From: Dave Abrahams <dave@boostpro.com>
Date: Sun, 23 Nov 2003 15:49:55 +0000
Subject: [PATCH] Workarounds for vc7

[SVN r20920]
---
 include/boost/multi_array.hpp                | 11 ++++--
 include/boost/multi_array/concept_checks.hpp | 23 ++++++------
 include/boost/multi_array/subarray.hpp       | 39 ++++++++++++++++++++
 3 files changed, 58 insertions(+), 15 deletions(-)

diff --git a/include/boost/multi_array.hpp b/include/boost/multi_array.hpp
index 03a601e..4674d0a 100644
--- a/include/boost/multi_array.hpp
+++ b/include/boost/multi_array.hpp
@@ -85,15 +85,20 @@ public:
     super_type((T*)initial_base_) {
     allocate_space();
   }
-
+    
   template <class ExtentList>
-  explicit multi_array(ExtentList const& extents) :
+  explicit multi_array(
+      ExtentList const& extents
+#ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
+    , typename detail::multi_array::disable_non_sub_array<ExtentList>::type* = 0
+#endif 
+  ) :
     super_type((T*)initial_base_,extents) {
     boost::function_requires<
       detail::multi_array::CollectionConcept<ExtentList> >();
     allocate_space();
   }
-
+    
   template <class ExtentList>
   explicit multi_array(ExtentList const& extents,
                        const general_storage_order<NumDims>& so) :
diff --git a/include/boost/multi_array/concept_checks.hpp b/include/boost/multi_array/concept_checks.hpp
index 6586618..148b691 100644
--- a/include/boost/multi_array/concept_checks.hpp
+++ b/include/boost/multi_array/concept_checks.hpp
@@ -61,7 +61,11 @@ namespace multi_array {
   struct ConstMultiArrayConcept
   {
     void constraints() {
-      //    function_requires< CopyConstructibleConcept<Array> >();
+    //    function_requires< CopyConstructibleConcept<Array> >();
+    function_requires< boost_concepts::ForwardTraversalConcept<iterator> >();
+    function_requires< boost_concepts::ReadableIteratorConcept<iterator> >();
+    function_requires< boost_concepts::ForwardTraversalConcept<const_iterator> >();
+    function_requires< boost_concepts::ReadableIteratorConcept<const_iterator> >();
 
       // RG - a( CollectionArchetype) when available...
       a[ id ];
@@ -100,11 +104,6 @@ namespace multi_array {
     typedef typename Array::extent_gen extent_gen;
     typedef typename Array::extent_range extent_range;
 
-    BOOST_CLASS_REQUIRE(iterator, boost_concepts, ForwardTraversalConcept);
-    BOOST_CLASS_REQUIRE(iterator, boost_concepts, ReadableIteratorConcept);
-    BOOST_CLASS_REQUIRE(const_iterator, boost_concepts, ForwardTraversalConcept);
-    BOOST_CLASS_REQUIRE(const_iterator, boost_concepts, ReadableIteratorConcept);
-                  
     Array a;
     size_type st;
     const size_type* stp;
@@ -124,6 +123,12 @@ namespace multi_array {
     void constraints() {
       //    function_requires< CopyConstructibleConcept<Array> >();
 
+      function_requires< boost_concepts::ForwardTraversalConcept<iterator> >();
+      function_requires< boost_concepts::ReadableIteratorConcept<iterator> >();
+      function_requires< boost_concepts::WritableIteratorConcept<iterator> >();
+      function_requires< boost_concepts::ForwardTraversalConcept<const_iterator> >();
+      function_requires< boost_concepts::ReadableIteratorConcept<const_iterator> >();
+      
       // RG - a( CollectionArchetype) when available...
       value_type vt = a[ id ];
 
@@ -186,12 +191,6 @@ namespace multi_array {
     typedef typename Array::extent_gen extent_gen;
     typedef typename Array::extent_range extent_range;
 
-    BOOST_CLASS_REQUIRE(iterator, boost_concepts, ForwardTraversalConcept);
-    BOOST_CLASS_REQUIRE(iterator, boost_concepts, ReadableIteratorConcept);
-    BOOST_CLASS_REQUIRE(iterator, boost_concepts, WritableIteratorConcept);
-    BOOST_CLASS_REQUIRE(const_iterator, boost_concepts, ForwardTraversalConcept);
-    BOOST_CLASS_REQUIRE(const_iterator, boost_concepts, ReadableIteratorConcept);
-      
     Array a;
     size_type st;
     const size_type* stp;
diff --git a/include/boost/multi_array/subarray.hpp b/include/boost/multi_array/subarray.hpp
index 00e8b9c..731c06d 100644
--- a/include/boost/multi_array/subarray.hpp
+++ b/include/boost/multi_array/subarray.hpp
@@ -194,6 +194,45 @@ private:
   const_sub_array& operator=(const const_sub_array&);
 };
 
+#ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
+//
+// Compilers that don't support partial ordering may need help to
+// disambiguate multi_array's templated constructors.  Even vc6/7 are
+// capable of some limited SFINAE, so we take the most-general version
+// out of the overload set with disable_non_sub_array.
+//
+template <typename T, std::size_t NumDims, typename TPtr>
+char is_sub_array_help(const_sub_array<T,NumDims,TPtr>&);
+
+char ( &is_sub_array_help(...) )[2];
+
+template <class T>
+struct is_sub_array
+{
+    static T x;
+    BOOST_STATIC_CONSTANT(bool, value = sizeof((is_sub_array_help)(x)) == 1);
+};
+
+template <bool sub_array = false>
+struct disable_non_sub_array_impl
+{
+    // forming a pointer to a reference triggers SFINAE
+    typedef int& type; 
+};
+
+template <>
+struct disable_non_sub_array_impl<true>
+{
+    typedef int type;
+};
+
+template <class T>
+struct disable_non_sub_array
+  : disable_non_sub_array_impl<is_sub_array<T>::value>
+{
+};
+#endif
+
 //
 // sub_array
 //    multi_array's proxy class to allow multiple overloads of