Added test to ensure that alignments of ctti_data and char are same

include/boost/type_index/ctti_type_index.hpp

@@ -63,6 +63,8 @@ inline const detail::ctti_data& ctti_construct() BOOST_NOEXCEPT {
     // “pointer to T1” to the type “pointer to T2” (where T1 and T2 are object types and where the alignment
     // requirements of T2 are no stricter than those of T1) and back to its original type yields the original pointer
     // value.
+    //
+    // Alignments are checked in `type_index_test_ctti_alignment.cpp` test.
     return *reinterpret_cast<const detail::ctti_data*>(boost::detail::ctti<T>::n());
 }
 

test/Jamfile.v2

@@ -40,6 +40,7 @@ test-suite type_index
     [ run testing_crossmodule.cpp test_lib_nortti $(tlib) : : : <rtti>off : testing_crossmodule_no_rtti ]
     [ compile-fail type_index_test_ctti_copy_fail.cpp ]
     [ compile-fail type_index_test_ctti_construct_fail.cpp ]
+    [ compile type_index_test_ctti_alignment.cpp ]
 
     # Mixing RTTI on and off
     [ link-fail testing_crossmodule.cpp $(tlib) test_lib_rtti : $(nortti) : link_fail_nortti_rtti ]

test/type_index_test_ctti_alignment.cpp

@@ -0,0 +1,18 @@
+//
+// Copyright Antony Polukhin, 2012-2013.
+//
+// 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/type_index/ctti_type_index.hpp>
+#include <boost/type_traits/alignment_of.hpp>
+
+int main() {
+    BOOST_STATIC_ASSERT_MSG(
+        boost::alignment_of<boost::typeind::detail::ctti_data>::value == boost::alignment_of<char>::value,
+        "Alignments of boost::typeind::detail::ctti_data and char differ. "
+        "It is unsafe to reinterpret_cast between them."
+    );
+}
+