Add test/append_described_4.cpp

test/Jamfile

@@ -58,6 +58,7 @@ run append_map.cpp ;
 run append_described.cpp ;
 run append_described_2.cpp ;
 run append_described_3.cpp ;
+run append_described_4.cpp ;
 
 run hash_append_5.cpp ;
 run hash_append_range.cpp ;

test/append_described_4.cpp

@@ -0,0 +1,64 @@
+// Copyright 2024 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/hash2/hash_append.hpp>
+#include <boost/hash2/fnv1a.hpp>
+#include <boost/describe/class.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+class X
+{
+private:
+
+    std::string s1_;
+    std::string s2_;
+
+    BOOST_DESCRIBE_CLASS(X, (), (), (), (s1_, s2_))
+
+public:
+
+    X(): s1_( "s1" ), s2_( "s2" )
+    {
+    }
+
+    std::string s1() const
+    {
+        return s1_;
+    }
+
+    std::string s2() const
+    {
+        return s2_;
+    }
+};
+
+template<class Hash, class Flavor, class R> void test( X const& x, R r )
+{
+    Flavor f;
+
+    {
+        Hash h;
+        hash_append( h, f, x );
+
+        BOOST_TEST_EQ( h.result(), r );
+    }
+
+    {
+        Hash h;
+        hash_append( h, f, x.s1() );
+        hash_append( h, f, x.s2() );
+
+        BOOST_TEST_EQ( h.result(), r );
+    }
+}
+
+int main()
+{
+    using namespace boost::hash2;
+
+    test<fnv1a_32, little_endian_flavor>( {}, 1388033884 );
+    test<fnv1a_32, big_endian_flavor>( {}, 3611226160 );
+
+    return boost::report_errors();
+}