Add get_deleter test with an incomplete class

test/Jamfile.v2

@@ -218,6 +218,8 @@ import testing ;
 
           [ run atomic_sp_constexpr_test.cpp ]
 
+          [ run get_deleter_test2.cpp ]
+
           [ run local_sp_test.cpp ]
           [ run lsp_array_test.cpp ]
           [ run lsp_array_n_test.cpp ]

test/get_deleter_test2.cpp

@@ -0,0 +1,37 @@
+//
+// get_deleter_test2.cpp
+//
+// Copyright 2017 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/core/lightweight_test.hpp>
+
+struct deleter;
+
+struct X
+{
+};
+
+static void test_get_deleter( boost::shared_ptr<X> const & p )
+{
+    BOOST_TEST( boost::get_deleter<deleter>( p ) != 0 );
+}
+
+struct deleter
+{
+    void operator()( X const * p ) { delete p; }
+};
+
+int main()
+{
+    boost::shared_ptr<X> p( new X, deleter() );
+
+    test_get_deleter( p );
+
+    return boost::report_errors();
+}