test_void_cast.cpp

来自「Boost provides free peer-reviewed portab」· C++ 代码 · 共 166 行

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// test_void_cast.cpp: test implementation of run-time casting of void pointers

// (C) Copyright 2002 Robert Ramey - http://www.rrsd.com . 
// Use, modification and distribution is subject to 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)
// <[e-mail]>

#include <cstddef> // NULL
#include "test_tools.hpp"
#include <boost/serialization/extended_type_info_typeid.hpp>
#include <boost/serialization/void_cast.hpp>
#include <boost/serialization/singleton.hpp>

class Base1
{
    char a;
};

class Base2
{
    int b;
};

class Derived : public Base1, public Base2
{
    long c;
};

class MostDerived : public Derived
{
    char d[32];
};

template<class T>
const boost::serialization::extended_type_info & eti(){
    return boost::serialization::singleton<
        boost::serialization::extended_type_info_typeid<T>
    >::get_const_instance();
}

int
test_main( int /* argc */, char* /* argv */[] )
{
    MostDerived md;
    MostDerived* pmd =& md;
    Derived* pd = static_cast<Derived*>(pmd);

    Base2* pb2 = static_cast<Base2*>(pmd);
    Base1* pb1 = static_cast<Base1*>(pd);

    void* vpmd = static_cast<void*>(pmd);
    void* vpb1 = static_cast<void*>(pb1);
    void* vpb2 = static_cast<void*>(pb2);
    void* vpd = static_cast<void*>(pd);

    // simple casts only requiring table lookup
    BOOST_CHECK(vpd == boost::serialization::void_downcast(
        eti<Derived>(),
        eti<Base1>(),
        vpb1
    ));
    BOOST_CHECK(vpb1 == boost::serialization::void_upcast(
        eti<Derived>(),
        eti<Base1>(),
        vpd  
    ));
    BOOST_CHECK(vpd == boost::serialization::void_downcast(  
        eti<Derived>(),
        eti<Base2>(),
        vpb2
    ));
    BOOST_CHECK(vpb2 == boost::serialization::void_upcast(
        eti<Derived>(),
        eti<Base2>(),
        vpd
    ));
    BOOST_CHECK(vpmd == boost::serialization::void_downcast(  
        eti<MostDerived>(),
        eti<Derived>(),
        vpd
    ));
    BOOST_CHECK(vpd == boost::serialization::void_upcast(
        eti<MostDerived>(),
        eti<Derived>(),
        vpmd
    ));
    // note relationship between MostDerived and Base1 is automatically derived
    BOOST_CHECK(vpmd == boost::serialization::void_downcast(  
        eti<MostDerived>(),
        eti<Base1>(),
        vpb1
    ));
    BOOST_CHECK(vpb1 == boost::serialization::void_upcast(
        eti<MostDerived>(),
        eti<Base1>(),
        vpmd
    ));

    // note relationship between MostDerived and Base2 is automatically derived
    BOOST_CHECK(vpmd == boost::serialization::void_downcast(  
        eti<MostDerived>(),
        eti<Base2>(),
        vpb2
    ));
    BOOST_CHECK(vpb2 == boost::serialization::void_upcast(
        eti<MostDerived>(),
        eti<Base2>(),
        vpmd
    ));

    // note: currently derivations are not optimised.  See void_cast.cpp
    // for and explanation.  These should still work though.

    // need to double check to validate speed up optimization of derivations
    BOOST_CHECK(vpmd == boost::serialization::void_downcast(  
        eti<MostDerived>(),
        eti<Base1>(),
        vpb1
    ));
    BOOST_CHECK(vpb1 == boost::serialization::void_upcast(
        eti<MostDerived>(),
        eti<Base1>(),
        vpmd
    ));
    BOOST_CHECK(vpmd == boost::serialization::void_downcast(
        eti<MostDerived>(),
        eti<Base2>(),
        vpb2
    ));
    BOOST_CHECK(vpb2 == boost::serialization::void_upcast(
        eti<MostDerived>(),
        eti<Base2>(),
        vpmd
    ));

    // check things that should fail
    BOOST_CHECK(NULL == boost::serialization::void_downcast(
        eti<Base2>(),
        eti<Base1>(),
        vpb1
    ));

    // note that a fundamental feature is that derived/base pairs are created
    // at compiler time so that all are registered before the main program starts
    // so leave the registration here at the end to verify this. Note bogus arguments
    // to workaround msvc 6 bug
    boost::serialization::void_cast_register<Derived, Base1>(
        static_cast<Derived *>(NULL),
        static_cast<Base1 *>(NULL)
    );
    boost::serialization::void_cast_register<Derived, Base2>(
        static_cast<Derived *>(NULL),
        static_cast<Base2 *>(NULL)
    );
    boost::serialization::void_cast_register<MostDerived, Derived>(
        static_cast<MostDerived *>(NULL),
        static_cast<Derived *>(NULL)
    );

    return EXIT_SUCCESS;
}

// EOF