Add support for described classes to hash.hpp

include/boost/container_hash/hash.hpp

@@ -26,7 +26,15 @@
 #include <boost/type_traits/make_unsigned.hpp>
 #include <boost/type_traits/enable_if.hpp>
 #include <boost/type_traits/conjunction.hpp>
+#include <boost/type_traits/is_union.hpp>
+#include <boost/describe/bases.hpp>
+#include <boost/describe/members.hpp>
 #include <boost/cstdint.hpp>
+
+#if defined(BOOST_DESCRIBE_CXX14)
+# include <boost/mp11/algorithm.hpp>
+#endif
+
 #include <string>
 #include <iterator>
 #include <complex>
@@ -384,6 +392,49 @@ namespace boost
         return boost::hash_unordered_range( v.begin(), v.end() );
     }
 
+#endif
+
+    // described classes
+
+#if defined(BOOST_DESCRIBE_CXX14)
+
+#if defined(_MSC_VER) && _MSC_VER == 1900
+# pragma warning(push)
+# pragma warning(disable: 4100) // unreferenced formal parameter
+#endif
+
+    template <typename T>
+    typename boost::enable_if_<container_hash::is_described_class<T>::value, std::size_t>::type
+        hash_value( T const& v )
+    {
+        static_assert( !boost::is_union<T>::value, "described unions are not supported" );
+
+        std::size_t r = 0;
+
+        using Bd = describe::describe_bases<T, describe::mod_any_access>;
+
+        mp11::mp_for_each<Bd>([&](auto D){
+
+            using B = typename decltype(D)::type;
+            boost::hash_combine( r, (B const&)v );
+
+        });
+
+        using Md = describe::describe_members<T, describe::mod_any_access>;
+
+        mp11::mp_for_each<Md>([&](auto D){
+
+            boost::hash_combine( r, v.*D.pointer );
+
+        });
+
+        return r;
+    }
+
+#if defined(_MSC_VER) && _MSC_VER == 1900
+# pragma warning(pop)
+#endif
+
 #endif
 
     // std::unique_ptr, std::shared_ptr

test/Jamfile.v2

@@ -109,3 +109,6 @@ run is_described_class_test2.cpp
   : : : <warnings>extra ;
 run is_described_class_test3.cpp
   : : : <warnings>extra ;
+
+run described_class_test.cpp
+  : : : <warnings>extra ;

test/described_class_test.cpp

@@ -0,0 +1,155 @@
+// Copyright 2022 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/describe/class.hpp>
+#include <boost/describe/operators.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+
+#if !defined(BOOST_DESCRIBE_CXX14)
+
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE( "Skipping test because BOOST_DESCRIBE_CXX14 is not defined" )
+
+int main() {}
+
+#else
+
+struct X1
+{
+    int m;
+    explicit X1( int m_ ): m( m_ ) {}
+};
+
+BOOST_DESCRIBE_STRUCT( X1, (), (m) )
+
+struct X2
+{
+    int m;
+    explicit X2( int m_ ): m( m_ ) {}
+};
+
+BOOST_DESCRIBE_STRUCT( X2, (), (m) )
+
+struct X3
+{
+    int m;
+    explicit X3( int m_ ): m( m_ ) {}
+};
+
+BOOST_DESCRIBE_STRUCT( X3, (), (m) )
+
+class Y: public X1, protected X2, private X3
+{
+public:
+
+    int m1;
+
+protected:
+
+    int m2;
+
+private:
+
+    int m3;
+
+public:
+
+    Y( int x1, int x2, int x3, int m1_, int m2_, int m3_ ):
+      X1( x1 ), X2( x2 ), X3( x3 ), m1( m1_ ), m2( m2_ ), m3( m3_ ) {}
+
+    BOOST_DESCRIBE_CLASS( Y, (X1, X2, X3), (m1), (m2), (m3) )
+};
+
+using boost::describe::operators::operator==;
+using boost::describe::operators::operator!=;
+using boost::describe::operators::operator<<;
+
+int main()
+{
+    Y y1( 0, 0, 0, 0, 0, 0 );
+
+    BOOST_TEST_EQ( y1, y1 );
+    BOOST_TEST_EQ( boost::hash<Y>()(y1), boost::hash<Y>()(y1) );
+
+    Y y2( 1, 0, 0, 0, 0, 0 );
+
+    BOOST_TEST_NE( y1, y2 );
+    BOOST_TEST_NE( boost::hash<Y>()(y1), boost::hash<Y>()(y2) );
+
+    Y y3( 0, 1, 0, 0, 0, 0 );
+
+    BOOST_TEST_NE( y1, y3 );
+    BOOST_TEST_NE( boost::hash<Y>()(y1), boost::hash<Y>()(y3) );
+
+    BOOST_TEST_NE( y2, y3 );
+    BOOST_TEST_NE( boost::hash<Y>()(y2), boost::hash<Y>()(y3) );
+
+    Y y4( 0, 0, 1, 0, 0, 0 );
+
+    BOOST_TEST_NE( y1, y4 );
+    BOOST_TEST_NE( boost::hash<Y>()(y1), boost::hash<Y>()(y4) );
+
+    BOOST_TEST_NE( y2, y4 );
+    BOOST_TEST_NE( boost::hash<Y>()(y2), boost::hash<Y>()(y4) );
+
+    BOOST_TEST_NE( y3, y4 );
+    BOOST_TEST_NE( boost::hash<Y>()(y3), boost::hash<Y>()(y4) );
+
+    Y y5( 0, 0, 0, 1, 0, 0 );
+
+    BOOST_TEST_NE( y1, y5 );
+    BOOST_TEST_NE( boost::hash<Y>()(y1), boost::hash<Y>()(y5) );
+
+    BOOST_TEST_NE( y2, y5 );
+    BOOST_TEST_NE( boost::hash<Y>()(y2), boost::hash<Y>()(y5) );
+
+    BOOST_TEST_NE( y3, y5 );
+    BOOST_TEST_NE( boost::hash<Y>()(y3), boost::hash<Y>()(y5) );
+
+    BOOST_TEST_NE( y4, y5 );
+    BOOST_TEST_NE( boost::hash<Y>()(y4), boost::hash<Y>()(y5) );
+
+    Y y6( 0, 0, 0, 0, 1, 0 );
+
+    BOOST_TEST_NE( y1, y6 );
+    BOOST_TEST_NE( boost::hash<Y>()(y1), boost::hash<Y>()(y6) );
+
+    BOOST_TEST_NE( y2, y6 );
+    BOOST_TEST_NE( boost::hash<Y>()(y2), boost::hash<Y>()(y6) );
+
+    BOOST_TEST_NE( y3, y6 );
+    BOOST_TEST_NE( boost::hash<Y>()(y3), boost::hash<Y>()(y6) );
+
+    BOOST_TEST_NE( y4, y6 );
+    BOOST_TEST_NE( boost::hash<Y>()(y4), boost::hash<Y>()(y6) );
+
+    BOOST_TEST_NE( y5, y6 );
+    BOOST_TEST_NE( boost::hash<Y>()(y5), boost::hash<Y>()(y6) );
+
+    Y y7( 0, 0, 0, 0, 0, 1 );
+
+    BOOST_TEST_NE( y1, y7 );
+    BOOST_TEST_NE( boost::hash<Y>()(y1), boost::hash<Y>()(y7) );
+
+    BOOST_TEST_NE( y2, y7 );
+    BOOST_TEST_NE( boost::hash<Y>()(y2), boost::hash<Y>()(y7) );
+
+    BOOST_TEST_NE( y3, y7 );
+    BOOST_TEST_NE( boost::hash<Y>()(y3), boost::hash<Y>()(y7) );
+
+    BOOST_TEST_NE( y4, y7 );
+    BOOST_TEST_NE( boost::hash<Y>()(y4), boost::hash<Y>()(y7) );
+
+    BOOST_TEST_NE( y5, y7 );
+    BOOST_TEST_NE( boost::hash<Y>()(y5), boost::hash<Y>()(y7) );
+
+    BOOST_TEST_NE( y6, y7 );
+    BOOST_TEST_NE( boost::hash<Y>()(y6), boost::hash<Y>()(y7) );
+
+    return boost::report_errors();
+}
+
+#endif