Add hash_forward_list_test.cpp

test/Jamfile.v2

@@ -88,3 +88,5 @@ build-project ../examples ;
 run detail_is_range_test.cpp ;
 run detail_is_contiguous_range_test.cpp ;
 run detail_is_unordered_range_test.cpp ;
+
+run hash_forward_list_test.cpp ;

test/hash_forward_list_test.cpp

@@ -0,0 +1,55 @@
+// Copyright 2021 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/container_hash/hash.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config.hpp>
+#include <boost/config/pragma_message.hpp>
+
+#if defined(BOOST_NO_CXX11_HDR_FORWARD_LIST)
+
+BOOST_PRAGMA_MESSAGE( "Test skipped, BOOST_NO_CXX11_HDR_FORWARD_LIST is defined" )
+int main() {}
+
+#else
+
+#include <forward_list>
+
+template<class T> void test()
+{
+    typedef std::forward_list<T> list;
+    typedef boost::hash<list> hash;
+
+    int const N = 32;
+
+    std::size_t h[ N ];
+
+    list v;
+
+    for( int i = 0; i < N; ++i )
+    {
+        h[ i ] = hash()( v );
+
+        BOOST_TEST_EQ( h[ i ], hash()( v ) );
+
+        for( int j = 0; j < i; ++j )
+        {
+            BOOST_TEST_NE( h[ j ], h[ i ] );
+        }
+
+        v.push_front( T() );
+    }
+}
+
+int main()
+{
+    test<int>();
+    test<float>();
+    test<double>();
+    test< std::forward_list<int> >();
+
+    return boost::report_errors();
+}
+
+#endif