Add test for make_shared's move-emulation support

This tests the functionality added with PR boostorg/smart_ptr#24.

Specifically this tests that passing moveable-only types to
constructors is possible through make_shared. Note that real rvalue's
still cannot be passed that way on C++03 unfortunately because there's
no generic way of accomplishing that with current move emulation.

test/Jamfile.v2

@@ -47,6 +47,7 @@ import testing ;
           [ run spinlock_try_test.cpp : : : <threading>multi : spinlock_try_test.mt ]
           [ run spinlock_pool_test.cpp ]
           [ run make_shared_test.cpp ]
+          [ run make_shared_move_emulation_test.cpp ]
           [ run make_shared_perfect_forwarding_test.cpp ]
           [ run shared_ptr_convertible_test.cpp ]
           [ run wp_convertible_test.cpp ]

test/make_shared_move_emulation_test.cpp

@@ -0,0 +1,81 @@
+// make_shared_move_emulation_test.cpp - a test of make_shared
+//   semi-perfect forwarding of constructor arguments when using a C++03
+//   compiler with move emulation.
+//   Note the "semi": it means moving temporaries (real r-values) doesn't work.
+//
+// Copyright 2016 Giel van Schijndel
+//
+// 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/detail/lightweight_test.hpp>
+#include <boost/make_shared.hpp>
+#include <boost/move/core.hpp>
+#include <boost/move/utility_core.hpp>
+#include <boost/shared_ptr.hpp>
+
+class movearg
+{
+private:
+    BOOST_MOVABLE_BUT_NOT_COPYABLE(movearg)
+public:
+    movearg()
+    {}
+    movearg(BOOST_RV_REF(movearg))
+    {}
+    movearg& operator=(BOOST_RV_REF(movearg))
+    {
+        return *this;
+    }
+};
+
+class ByVal
+{
+public:
+    ByVal(movearg) {}
+};
+
+class ByRef
+{
+public:
+    enum constructor_id
+    {
+        move_constructor,
+        const_ref_constructor
+    };
+
+    ByRef(BOOST_RV_REF(movearg)): constructed_by_(move_constructor)
+    {}
+    ByRef(const movearg &arg): constructed_by_(const_ref_constructor)
+    {}
+
+    constructor_id constructed_by_;
+};
+
+int main()
+{
+    {
+        movearg a;
+        boost::shared_ptr< ByVal > x = boost::make_shared< ByVal >(boost::move(a));
+    }
+    {
+        movearg a;
+        boost::shared_ptr< ByRef > x = boost::make_shared< ByRef >(boost::move(a));
+        BOOST_TEST( x->constructed_by_ == ByRef::move_constructor);
+    }
+#if !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
+    {
+        boost::shared_ptr< ByVal > x = boost::make_shared< ByVal >(movearg());
+        boost::shared_ptr< ByRef > y = boost::make_shared< ByRef >(movearg());
+        BOOST_TEST( y->constructed_by_ == ByRef::move_constructor);
+    }
+#endif // !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
+    {
+        const movearg ca;
+        boost::shared_ptr< ByRef > x = boost::make_shared< ByRef >(ca);
+        BOOST_TEST( x->constructed_by_ == ByRef::const_ref_constructor);
+    }
+
+    return boost::report_errors();
+}