Ticket #1946: tt_failure.cpp

/*
 *    Compile with: cl -MD -I. -EHsc -O2 tt_failure.cpp
 *
 *    tt_failure.cpp
 *    .\boost/type_traits/type_with_alignment.hpp(206) : error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>'
 *            with
 *            [
 *                x=false
 *            ]
 *            .\boost/type_traits/type_with_alignment.hpp(218) : see reference to class template instantiation 'boost::detail::type_with_alignment_imp<Align>' being compiled
 *            with
 *            [
 *                Align=12
 *            ]
 *            tt_failure.cpp(36) : see reference to class template instantiation 'boost::type_with_alignment<Align>' being compiled
 *            with
 *            [
 *                Align=12
 *            ]
 *    .\boost/type_traits/type_with_alignment.hpp(207) : error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>'
 *            with
 *            [
 *                x=false
 *            ]
 */

#include <boost/function.hpp>
#include <boost/type_traits/alignment_of.hpp>
#include <boost/type_traits/type_with_alignment.hpp>

#ifdef _MSC_VER
// This kind of packing is set within MSVC 9.0 headers.
// E.g. std::ostream has it.
#pragma pack(push,8)
#endif  /* _MSC_VER */

// The issue is gone if Root has no data members
struct Root { int a; };
// The issue is gone if Root is inherited non-virtually
struct A : virtual public Root {};

#ifdef _MSC_VER
#pragma pack(pop)
#endif  /* _MSC_VER */

// The class gets alignment 12 for some reason
// The real-world case that triggered the problem is a user-defined stream class that
// derived from std::ostream. Such class could not be used with tools involving type_with_alignment.
class my_class :
    public A
{
public:
    // The issue is gone if the type is not a boost::function. The signature doesn't matter.
    typedef boost::function0< void > function_type;
    function_type m_function;
};


int main(int, char*[])
{
    boost::type_with_alignment<
        boost::alignment_of<
            my_class
        >::value
    >::type obj;

    return static_cast< int >(&obj != NULL);
}