From 3002a898a0a980017af146b89e7f843ef0d5d010 Mon Sep 17 00:00:00 2001
From: Daniel James <daniel@calamity.org.uk>
Date: Sun, 16 Dec 2007 18:20:25 +0000
Subject: [PATCH] If the containers have equality comparisons, they'll also
 need 'hash_value'. Untested and undocumented, as before.

[SVN r42108]
---
 doc/ref.xml                                   | 80 +++++++++++++++++++
 .../unordered/detail/hash_table_impl.hpp      | 35 ++++++++
 include/boost/unordered_map.hpp               | 12 ++-
 include/boost/unordered_set.hpp               | 12 ++-
 test/container/compile_tests.hpp              |  5 ++
 test/objects/minimal.hpp                      |  4 +
 6 files changed, 146 insertions(+), 2 deletions(-)

diff --git a/doc/ref.xml b/doc/ref.xml
index c0e4bc30..58e14a95 100644
--- a/doc/ref.xml
+++ b/doc/ref.xml
@@ -636,6 +636,25 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
                 <para>This is a boost extension.</para>
               </notes>
             </function>
+            <function name="hash_value">
+              <template>
+                <template-type-parameter name="Value">
+                </template-type-parameter>
+                <template-type-parameter name="Hash">
+                </template-type-parameter>
+                <template-type-parameter name="Pred">
+                </template-type-parameter>
+                <template-type-parameter name="Alloc">
+                </template-type-parameter>
+              </template>
+              <parameter name="x">
+                <paramtype>unordered_set&lt;Value, Hash, Pred, Alloc&gt; const&amp;</paramtype>
+              </parameter>
+              <type>std::size_t</type>
+              <notes>
+                <para>This is a boost extension.</para>
+              </notes>
+            </function>
           </free-function-group>
           <free-function-group name="swap">
             <function name="swap">
@@ -1293,6 +1312,25 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
                 <para>This is a boost extension.</para>
               </notes>
             </function>
+            <function name="hash_value">
+              <template>
+                <template-type-parameter name="Value">
+                </template-type-parameter>
+                <template-type-parameter name="Hash">
+                </template-type-parameter>
+                <template-type-parameter name="Pred">
+                </template-type-parameter>
+                <template-type-parameter name="Alloc">
+                </template-type-parameter>
+              </template>
+              <parameter name="x">
+                <paramtype>unordered_multiset&lt;Value, Hash, Pred, Alloc&gt; const&amp;</paramtype>
+              </parameter>
+              <type>std::size_t</type>
+              <notes>
+                <para>This is a boost extension.</para>
+              </notes>
+            </function>
           </free-function-group>
           <free-function-group name="swap">
             <function name="swap">
@@ -2005,6 +2043,27 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
                 <para>This is a boost extension.</para>
               </notes>
             </function>
+            <function name="hash_value">
+              <template>
+                <template-type-parameter name="Key">
+                </template-type-parameter>
+                <template-type-parameter name="Mapped">
+                </template-type-parameter>
+                <template-type-parameter name="Hash">
+                </template-type-parameter>
+                <template-type-parameter name="Pred">
+                </template-type-parameter>
+                <template-type-parameter name="Alloc">
+                </template-type-parameter>
+              </template>
+              <parameter name="x">
+                <paramtype>unordered_map&lt;Key, Mapped, Hash, Pred, Alloc&gt; const&amp;</paramtype>
+              </parameter>
+              <type>std::size_t</type>
+              <notes>
+                <para>This is a boost extension.</para>
+              </notes>
+            </function>
           </free-function-group>
           <free-function-group name="swap">
             <function name="swap">
@@ -2676,6 +2735,27 @@ file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
                 <para>This is a boost extension.</para>
               </notes>
             </function>
+            <function name="hash_value">
+              <template>
+                <template-type-parameter name="Key">
+                </template-type-parameter>
+                <template-type-parameter name="Mapped">
+                </template-type-parameter>
+                <template-type-parameter name="Hash">
+                </template-type-parameter>
+                <template-type-parameter name="Pred">
+                </template-type-parameter>
+                <template-type-parameter name="Alloc">
+                </template-type-parameter>
+              </template>
+              <parameter name="x">
+                <paramtype>unordered_multimap&lt;Key, Mapped, Hash, Pred, Alloc&gt; const&amp;</paramtype>
+              </parameter>
+              <type>std::size_t</type>
+              <notes>
+                <para>This is a boost extension.</para>
+              </notes>
+            </function>
           </free-function-group>
           <free-function-group name="swap">
             <function name="swap">
diff --git a/include/boost/unordered/detail/hash_table_impl.hpp b/include/boost/unordered/detail/hash_table_impl.hpp
index 30e662a6..98aac7db 100644
--- a/include/boost/unordered/detail/hash_table_impl.hpp
+++ b/include/boost/unordered/detail/hash_table_impl.hpp
@@ -1926,6 +1926,41 @@ public:
                 return true;
             }
 
+            inline bool group_hash(local_iterator_base it, type_wrapper<key_type>*) const
+            {
+                std::size_t seed = group_count(it);
+                boost::hash_combine(seed, hash_function()(*it));
+                return seed;
+            }
+
+            inline bool group_hash(local_iterator_base it, void*) const
+            {
+                std::size_t seed = hash_function()(it->first);
+
+                local_iterator_base end = it;
+                end.next_group();
+
+                do {
+                    boost::hash_combine(seed, it->second);
+                } while(it != end);
+
+                return seed;
+            }
+
+            std::size_t hash_value() const
+            {
+                std::size_t seed = 0;
+
+                for(bucket_ptr i = this->cached_begin_bucket_,
+                        j = this->buckets_ + this->bucket_count_; i != j; ++i)
+                {
+                    for(local_iterator_base it(i->next_); it.not_finished(); it.next_group())
+                        seed ^= group_hash(it, (type_wrapper<value_type>*)0);
+                }
+
+                return seed;
+            }
+
         private:
 
             // strong exception safety, no side effects
diff --git a/include/boost/unordered_map.hpp b/include/boost/unordered_map.hpp
index 6fe05b69..7dd7b185 100644
--- a/include/boost/unordered_map.hpp
+++ b/include/boost/unordered_map.hpp
@@ -16,8 +16,8 @@
 #include <functional>
 #include <memory>
 
-#include <boost/unordered/detail/hash_table.hpp>
 #include <boost/functional/hash.hpp>
+#include <boost/unordered/detail/hash_table.hpp>
 
 namespace boost
 {
@@ -335,6 +335,11 @@ namespace boost
         {
             return !m1.base.equals(m2.base);
         }
+
+        friend std::size_t hash_value(unordered_map const& m)
+        {
+            return m.base.hash_value();
+        }
     }; // class template unordered_map
 
     template <class K, class T, class H, class P, class A>
@@ -642,6 +647,11 @@ namespace boost
         {
             return !m1.base.equals(m2.base);
         }
+
+        friend std::size_t hash_value(unordered_multimap const& m)
+        {
+            return m.base.hash_value();
+        }
     }; // class template unordered_multimap
 
     template <class K, class T, class H, class P, class A>
diff --git a/include/boost/unordered_set.hpp b/include/boost/unordered_set.hpp
index 9f713587..f20aef0c 100644
--- a/include/boost/unordered_set.hpp
+++ b/include/boost/unordered_set.hpp
@@ -16,8 +16,8 @@
 #include <functional>
 #include <memory>
 
-#include <boost/unordered/detail/hash_table.hpp>
 #include <boost/functional/hash.hpp>
+#include <boost/unordered/detail/hash_table.hpp>
 
 namespace boost
 {
@@ -305,6 +305,11 @@ namespace boost
         {
             return !m1.base.equals(m2.base);
         }
+
+        friend std::size_t hash_value(unordered_set const& m)
+        {
+            return m.base.hash_value();
+        }
     }; // class template unordered_set
 
     template <class T, class H, class P, class A>
@@ -597,6 +602,11 @@ namespace boost
         {
             return !m1.base.equals(m2.base);
         }
+
+        friend std::size_t hash_value(unordered_multiset const& m)
+        {
+            return m.base.hash_value();
+        }
     }; // class template unordered_multiset
 
     template <class T, class H, class P, class A>
diff --git a/test/container/compile_tests.hpp b/test/container/compile_tests.hpp
index 19455aba..c8a22ae7 100644
--- a/test/container/compile_tests.hpp
+++ b/test/container/compile_tests.hpp
@@ -129,4 +129,9 @@ void equality_test(X& r, T&)
 
     test::check_return_type<bool>::equals(a == b);
     test::check_return_type<bool>::equals(a != b);
+#if defined(BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP)
+    test::check_return_type<std::size_t>::equals(boost::hash_value(a));
+#else
+    test::check_return_type<std::size_t>::equals(hash_value(a));
+#endif
 }
diff --git a/test/objects/minimal.hpp b/test/objects/minimal.hpp
index a1450437..f8f84445 100644
--- a/test/objects/minimal.hpp
+++ b/test/objects/minimal.hpp
@@ -57,6 +57,10 @@ namespace minimal
         return false;
     }
 
+    std::size_t hash_value(copy_constructible_equality_comparable) {
+        return 1;
+    }
+
     class default_copy_constructible
     {
     public: