From 69aa01ec001ac2a737274fb7738d2c370fac3d19 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Thu, 24 Feb 2011 23:24:54 +0000
Subject: [PATCH] Add hash_value for shared_ptr; prevents hash_value( bool )
 from being used. Refs #5216.

[SVN r69260]
---
 include/boost/smart_ptr/shared_ptr.hpp | 12 ++++++++-
 test/Jamfile.v2                        |  1 +
 test/sp_hash_test.cpp                  | 34 ++++++++++++++++++++++++++
 3 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 test/sp_hash_test.cpp

diff --git a/include/boost/smart_ptr/shared_ptr.hpp b/include/boost/smart_ptr/shared_ptr.hpp
index 66ab48a..16a1f92 100644
--- a/include/boost/smart_ptr/shared_ptr.hpp
+++ b/include/boost/smart_ptr/shared_ptr.hpp
@@ -41,6 +41,7 @@
 #include <algorithm>            // for std::swap
 #include <functional>           // for std::less
 #include <typeinfo>             // for std::bad_cast
+#include <cstddef>              // for std::size_t
 
 #if !defined(BOOST_NO_IOSTREAM)
 #if !defined(BOOST_NO_IOSFWD)
@@ -722,7 +723,16 @@ template<class T> inline bool atomic_compare_exchange_explicit( shared_ptr<T> *
     return atomic_compare_exchange( p, v, w ); // std::move( w )
 }
 
-#endif
+#endif // !defined(BOOST_SP_NO_ATOMIC_ACCESS)
+
+// hash_value
+
+template< class T > struct hash;
+
+template< class T > std::size_t hash_value( boost::shared_ptr<T> const & p )
+{
+    return boost::hash< T* >()( p.get() );
+}
 
 } // namespace boost
 
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 95e0654..632ef08 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -65,5 +65,6 @@ import testing ;
           [ run atomic_count_test2.cpp ]
           [ run sp_typeinfo_test.cpp ]
           [ compile make_shared_fp_test.cpp ]
+          [ run sp_hash_test.cpp ]
         ;
 }
diff --git a/test/sp_hash_test.cpp b/test/sp_hash_test.cpp
new file mode 100644
index 0000000..b67f547
--- /dev/null
+++ b/test/sp_hash_test.cpp
@@ -0,0 +1,34 @@
+//
+// sp_hash_test.cpp
+//
+// Copyright 2011 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0.
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+//
+
+#include <boost/shared_ptr.hpp>
+#include <boost/functional/hash.hpp>
+#include <boost/detail/lightweight_test.hpp>
+
+int main()
+{
+    boost::hash< boost::shared_ptr<int> > hasher;
+
+    boost::shared_ptr< int > p1, p2( p1 ), p3( new int ), p4( p3 ), p5( new int );
+
+    BOOST_TEST_EQ( p1, p2 );
+    BOOST_TEST_EQ( hasher( p1 ), hasher( p2 ) );
+
+    BOOST_TEST_NE( p1, p3 );
+    BOOST_TEST_NE( hasher( p1 ), hasher( p3 ) );
+
+    BOOST_TEST_EQ( p3, p4 );
+    BOOST_TEST_EQ( hasher( p3 ), hasher( p4 ) );
+
+    BOOST_TEST_NE( p3, p5 );
+    BOOST_TEST_NE( hasher( p3 ), hasher( p5 ) );
+
+    return boost::report_errors();
+}